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Turbocharging a lawn mower

#1

W

wineman

Have any of you used any of the following and what were the results?

www.outdoorpowerllc.net

Boosted Mowers. Lawn Mower Turbo Kit

If you're looking for a way to boost the performance of your lawn mower, a turbo kit is the perfect solution. With the right kit, you can increase horsepower, improve fuel efficiency, and get a cleaner, healthier lawn. Fortunately, Amazon offers a wide selection of lawn mower turbo kits that are...
www.outdoorpowerllc.net www.outdoorpowerllc.net

Thanks
TBB


#2

Hammermechanicman

Hammermechanicman

No idea about that kit but once routed a 1 1/2" hose from the fan shroud to the carb on a 5hp briggs. It did up the top end but was a bear to tune. Had to richen up the main jet for top end and ran rich at partial throttle.


#3

W

wineman

Hammermechanicman said:
No idea about that kit but once routed a 1 1/2" hose from the fan shroud to the carb on a 5hp briggs. It did up the top end but was a bear to tune. Had to richen up the main jet for top end and ran rich at partial throttle.
Click to expand...
Thanks. Do you know if you brought up the horsepower?

T


#4

B

bertsmobile1

Why are you doing this
Hp is Torque x revs


#5

Hammermechanicman

Hammermechanicman

wineman said:
Thanks. Do you know if you brought up the horsepower?

T
Click to expand...
Only top end. This was on a go cart. Even with different gearing the engine would top out right at 6300 rpm. This is with no govenor and wide open throttle. After the tube was connected it topped out about 6700. Didn't help the acceleration so no gain in the midrange and 6500 is about the limit for a stock rod so dumped the idea. It was just a "what if" experiment anyway.


#6

W

wineman

bertsmobile1 said:
Why are you doing this
Hp is Torque x revs
Click to expand...
It is a Murray walk behind mower and the grass is very thick and the mower sometimes has trouble getting through it. I have received numerous suggestions to add a turbocharger and get rid of the muffler. I have been told with this being an OVC that it will double the power and that the muffler is taking away power.

Thanks


#7

Farmer Jean

Farmer Jean

I'd be interested in hearing about it too. I wouldn't use one on my lawn-cutting rigs, but a mud-mower would be fun.

Turbo-Kaboom!


#8

Hammermechanicman

Hammermechanicman

Someone is BSing you.


#9

W

wineman

Hammermechanicman said:
Someone is BSing you.
Click to expand...
Are you referring to my post and if so, why do you say that? What am I missing?

Thanks

TBB


#10

Hammermechanicman

Hammermechanicman

A single cylinder governed engine running 3400 rpm would respond to a positive displacement supercharger but you won't get enough exhaust to properly spin a turbo to get any midrange improvement. You need at least a twin cylinder engine for a turbo to work. The kits in your link are for multi cylinder 500cc or bigger engines. Trying to turbocharge a push mower would be very difficult and probably cheaper to just buy a mower with a bigger engine.


#11

B

bertsmobile1

The phrase silk purse from a sows ear comes to mind
It is not as simple as just bolting on a kit
You would need a steel con rod , more or larger head bolts , modified governor , new crankshaft dynamically balanced + the kit costs which even without labour would be more expensive than a bigger engine.
Next you will not double Hp unless you double revs and if you try running it at 7000 rpm then little end will depart the can rod if the crankcase does not explode first .
After that increased engine speed will change the airflow dynamics under the deck so it might not cut the grass at all.
I have done some racing engines and these came to well over $ 1000 just in parts and for that there was no doubling of Hp .
The muffler does not "take away" Hp but tuning the exhaust will help breathing and more efficient cylinder filling over a specific narrow range of engine revs .
Adding weight can help prevent bogging down
A lot of old 30" to 40" ride ons were fitted with small 8 Hp engines but they had very heavy cast iron pulleys to store momentum

Who ever has been feeding you this guff has spent too many hours on Face Book & You Tube .


#12

W

wineman

Hammermechanicman said:
A single cylinder governed engine running 3400 rpm would respond to a positive displacement supercharger but you won't get enough exhaust to properly spin a turbo to get any midrange improvement. You need at least a twin cylinder engine for a turbo to work. The kits in your link are for multi cylinder 500cc or bigger engines. Trying to turbocharge a push mower would be very difficult and probably cheaper to just buy a mower with a bigger engine.
Click to expand...
I see, however the person that referred me to this procedure, showed me a video that moved the running rpm's to 6000 and had an addition that allowed more air flow. Does that make any sense?

Thanks


#13

W

wineman

bertsmobile1 said:
The phrase silk purse from a sows ear comes to mind
It is not as simple as just bolting on a kit
You would need a steel con rod , more or larger head bolts , modified governor , new crankshaft dynamically balanced + the kit costs which even without labour would be more expensive than a bigger engine.
Next you will not double Hp unless you double revs and if you try running it at 7000 rpm then little end will depart the can rod if the crankcase does not explode first .
After that increased engine speed will change the airflow dynamics under the deck so it might not cut the grass at all.
I have done some racing engines and these came to well over $ 1000 just in parts and for that there was no doubling of Hp .
The muffler does not "take away" Hp but tuning the exhaust will help breathing and more efficient cylinder filling over a specific narrow range of engine revs .
Adding weight can help prevent bogging down
A lot of old 30" to 40" ride ons were fitted with small 8 Hp engines but they had very heavy cast iron pulleys to store momentum

Who ever has been feeding you this guff has spent too many hours on Face Book & You Tube .
Click to expand...
I had asked about some of what you said,but the people indicated there will be no such problem. They also said the current head-bolts should hold with no problem. I was concerned if it would cause engine failure and they indicated to put in differential oil and that would solve the problem.

Thanks


#14

Hammermechanicman

Hammermechanicman

You are talking about a single cylinder push mower engine which is probably 8 to 10 cubic inch displacement. Here are some reasons why turbocharging such an engine is difficult. First is exhaust reversion. When a single cylinder engine closes the exhaust valve the exhaust gases literally stop until the exhaust valve opens again and gasses are pushed out. This cycle of pressure and no pressure is called exhaust reversion. Not what you want to spin a turbo. Second reason is exhaust gas volume. Turbos need to spin at least 3k to 4k to start to build boost. Look at the size of a turbo on a 2.5L (150CID) car engine and now scale it down to a 8 CID engine governed at 3400 RPM. It will be a pretty small turbo. Next is the carb. Trying to pressurize a simple push mower carb to deal with varying degrees of vacum and boost and properly meter fuel at different loads and RPM would be a nightmare. Cooling would be an issue since the engine is designed to cool at a certain power output. More power equals more heat.

I would like to see a working turbocharged push mower from the folks you are talking to.

Different oil fixes a problem??????


#15

Hammermechanicman

Hammermechanicman

wineman said:
I see, however the person that referred me to this procedure, showed me a video that moved the running rpm's to 6000 and had an addition that allowed more air flow. Does that make any sense?

Thanks
Click to expand...
Are you planning to run the engine at 6000 RPM?


#16

B

bertsmobile1

It is your engine and your money so go piss it up against the wall as you seem to be determined to do that
You have just had 2 techs tell you it will not work and you run the risk of destroying your engine if by some miracle it does work
Very few mower engines will run over 5000 rpm for any length of time
The con rod is simply not strong enough
When the governor fails usually the piston ends up slamming into the head because the rod fails
These engines are a cheap as it is possible to make them
Then there is the balance factor , they are not balanced to 6000 rpm
When I do a racing engine they have to be dynamically balanced, particularly the flywheels
I can make a mower engine do 10,000 rpm if I want to, but it won't do that for any length of time

Then as previously mentioned you have airflow under the deck to consider
In many cases over speeding the engine will cause either the grass to build up under the deck till it chokes the mower or will toss rocks 60' out the chute or right through the side of the deck
Just increasing the speed from 3200 to 3600 on a Honda buggered the deck within a single season .
Next striking an object ( tree root for instance ) at double the revs will probably bend the crankshaft like a bannana
And on top of that there is blade balance to take into account
The faster the blade spins the higher the level off balance needed .

This is my last word on this thread
No use talking if the other party refuses to listen
and note neither Hammer nor I make a cent for giving you sound advice where as the other clot is trying to sell you a trick up kit that will not work .


#17

C

CraigH

I'm curious, how much have you been quoted for the turbo and related parts to convert the engine you have?
And have the people who have been giving you advice on this actually shown you a running single cylinder mower engine with their turbo kit on it?


#18

W

wineman

CraigH said:
I'm curious, how much have you been quoted for the turbo and related parts to convert the engine you have?
And have the people who have been giving you advice on this actually shown you a running single cylinder mower engine with their turbo kit on it?
Click to expand...
Yes and I can get is done for $75.


#19

W

wineman

bertsmobile1 said:
It is your engine and your money so go piss it up against the wall as you seem to be determined to do that
You have just had 2 techs tell you it will not work and you run the risk of destroying your engine if by some miracle it does work
Very few mower engines will run over 5000 rpm for any length of time
The con rod is simply not strong enough
When the governor fails usually the piston ends up slamming into the head because the rod fails
These engines are a cheap as it is possible to make them
Then there is the balance factor , they are not balanced to 6000 rpm
When I do a racing engine they have to be dynamically balanced, particularly the flywheels
I can make a mower engine do 10,000 rpm if I want to, but it won't do that for any length of time

Then as previously mentioned you have airflow under the deck to consider
In many cases over speeding the engine will cause either the grass to build up under the deck till it chokes the mower or will toss rocks 60' out the chute or right through the side of the deck
Just increasing the speed from 3200 to 3600 on a Honda buggered the deck within a single season .
Next striking an object ( tree root for instance ) at double the revs will probably bend the crankshaft like a bannana
And on top of that there is blade balance to take into account
The faster the blade spins the higher the level off balance needed .

This is my last word on this thread
No use talking if the other party refuses to listen
and note neither Hammer nor I make a cent for giving you sound advice where as the other clot is trying to sell you a trick up kit that will not work .
Click to expand...
Thanks for your help. I have bought one of the kits and will let you know what happens to the mower.It is fairly new, so it should tolerate more power.


#20

Hammermechanicman

Hammermechanicman

wineman said:
Yes and I can get is done for $75.
Click to expand...
Link to kit? I am curious.


#21

C

CraigH

wineman said:
Yes and I can get is done for $75.
Click to expand...
That's an amazing price!
What do you get for your $75, is there a manifold and boost pipes included?
Would you be able to post a link or even pm me the details please.


#22

Hammermechanicman

Hammermechanicman

CraigH said:
That's an amazing price!
What do you get for your $75, is there a manifold and boost pipes included?
Would you be able to post a link or even pm me the details please.
Click to expand...
I would ba amazed if even the chineese could make a turbo for $75. What type of bearings are they using to withstand the heat with no oil cooling? Or is it called a turbo kit and is just a fancy air cleaner and muffler on a pipe?


#23

C

CraigH

Hammermechanicman said:
I would ba amazed if even the chineese could make a turbo for $75. What type of bearings are they using to withstand the heat with no oil cooling? Or is it called a turbo kit and is just a fancy air cleaner and muffler on a pipe?
Click to expand...
My thoughts exactly..


#24

J

jkp62

wineman said:
It is a Murray walk behind mower and the grass is very thick and the mower sometimes has trouble getting through it. I have received numerous suggestions to add a turbocharger and get rid of the muffler. I have been told with this being an OVC that it will double the power and that the muffler is taking away power.

Thanks
Click to expand...
Find a used Lawnboy with the Duraforce , mine goes through anything ( long , wet , thick ) . Paid $50 for it .


#25

T

troverman

I'm curious if you can make it work. I personally don't think it will work, and I also think a $75 turbo kit means it will be incredibly poor quality. It seems just buying a more powerful engine that fits your mower's bolt pattern would be the most effective solution. For example, a Harbor Freight Predator (Honda knockoff) engine that is rated for more power than your engine. What is the current engine you have on your Murray? Horsepower rating? I have a 21" Honda walk behind with a 6.5HP engine and it will bog down in tall grass. Kind of the nature of the beast.


#26

MyGrassHasCrabs

MyGrassHasCrabs

"The flame that burns twice as bright burns half as long."

Seems to me that increasing the RPM also increases the wear on the engine...might be something to consider.


#27

Moparjoe499

Moparjoe499

wineman said:
Have any of you used any of the following and what were the results?

www.outdoorpowerllc.net

Boosted Mowers. Lawn Mower Turbo Kit

If you're looking for a way to boost the performance of your lawn mower, a turbo kit is the perfect solution. With the right kit, you can increase horsepower, improve fuel efficiency, and get a cleaner, healthier lawn. Fortunately, Amazon offers a wide selection of lawn mower turbo kits that are...
www.outdoorpowerllc.net www.outdoorpowerllc.net

Thanks
TBB
Click to expand...
WHAT STUPID IDIOT WOULD WANT TO DO THAT TO A LAWN MOWER.


#28

G

Gord Baker

wineman said:
It is a Murray walk behind mower and the grass is very thick and the mower sometimes has trouble getting through it. I have received numerous suggestions to add a turbocharger and get rid of the muffler. I have been told with this being an OVC that it will double the power and that the muffler is taking away power.

Thanks
Click to expand...
Cut the lawn more often @ 3-½" and buy a new Gas Powered Mower while you still can! Take good care of it.
Forget all the magic crap. I tried Hi Compression Floor Mats in my Youth. Did not help HP and used more Fuel.


#29

C

Chipg1956

bertsmobile1 said:
Why are you doing this
Hp is Torque x revs
Click to expand...
torque x RPM / 5251.1 =HP
In order to add a turbo you would need to also add some sort of pressurized oiling system. I am guessing that the kits you showed are for larger engines.


#30

Reverett

Reverett

Why not just buy a mower more suited to your mowing needs or mow more often. I read this thread in amazement that this would even exist for a single cylinder engine. I guess you can sell anything to someone who doesn't know better!


#31

T

tschwarting

Hammermechanicman said:
A single cylinder governed engine running 3400 rpm would respond to a positive displacement supercharger but you won't get enough exhaust to properly spin a turbo to get any midrange improvement. You need at least a twin cylinder engine for a turbo to work. The kits in your link are for multi cylinder 500cc or bigger engines. Trying to turbocharge a push mower would be very difficult and probably cheaper to just buy a mower with a bigger engine.
Click to expand...
Think Tim Allen of Home Improvement fame = MORE POWER!!


#32

Mike88se

Mike88se

I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.


#33

Hammermechanicman

Hammermechanicman

Famous quote "Let's not confuse the issue with facts."
🤣
Still waiting for the link.


#34

EatPreyMow

EatPreyMow

Those little engines aren't designed for boost, they are designed to be as cheap to manufacture as possible which means they aren't built to handle an extra 30% of power/torque. Even if you successfully tune the carburetor and achieve higher power output then it will at best mow slightly better for a while until the rod breaks or your head gasket blows. If you decide to raise the RPMs then you have the blade spinning far beyond design spec so it could fragment and cause a word of hurt for you or a bystander.

I see two alternatives.
  1. Buy a larger displacement engine. It will be designed to produce higher torque at mowing speeds so there will be less bogging, and it will last. You won't mow your lawn significantly faster but it will be less frustrating.
  2. Buy a better lawnmower. Get a wider deck or better yet get a riding mower. You will finish mowing far faster and you can sell your old mower since it hasn't had a turbo hacked onto it.
This is a good time of year to find deals on used lawn mowers so that's what I'd do.


#35

T

TobyU

wineman said:
Have any of you used any of the following and what were the results?

www.outdoorpowerllc.net

Boosted Mowers. Lawn Mower Turbo Kit

If you're looking for a way to boost the performance of your lawn mower, a turbo kit is the perfect solution. With the right kit, you can increase horsepower, improve fuel efficiency, and get a cleaner, healthier lawn. Fortunately, Amazon offers a wide selection of lawn mower turbo kits that are...
www.outdoorpowerllc.net www.outdoorpowerllc.net

Thanks
TBB
Click to expand...
It's absolutely silly and absurd for anyone to be interested in this kind of thing for a lawn mower that's actually used to cut grass.
Even the current horsepower ratings we have, even though they're kind of a joke and erroneously high, still have far more power than we need to cut our lawns!

The only thing I can see this being worthwhile for are the play toys and race or pulling mowers people do.
This is not some makeshift play around kit but a real turbocharger and would certainly give huge power increases but it also would come with other complications with tuning and then with exhaust etc but I'm assuming anyone wanting to build this kind of power for pulling purposes etc is using a custom exhaust of a very large size or rather a dump and using the size to help tune exhaust scavenging etc.

Now in the play around version of Turbo charging lawn mower I've done that several times just for fun.

The quickest and easiest way has always been with a leaf blower but you can also use anything where you have a controlled or consistent flow of air like a shop vac exhaust or compressed air etc.
All you have to do is add an extra fuel source

So you take your handheld leaf blower whether it be gasoline or a battery powered one and then you drill you a hole somewhere around 8 in from the end of they discharged tube there where the air comes out and you pipe you a little hose brass fitting spray tip nozzle etc into there.
You need Subway to control the size of the bottom like a fixed orifice etc but many things can be adapted.
Then you run you a piece of tubing, preferably clear so you can see the fuel flow to a fuel tank source and when you blow the air out the blower it will suck the fuel out and you can adjust everything just right with your speed and with the orifice size so you're blowing a gasoline enriched mixture of air coming out of the end.
Now of course you can take this makeshift design a little further and turn it into a flamethrower too but none of it is very safe.

So you just pipe the leaf blower into the intake with various plastic hose and adapter assemblies like PVC or Shop-Vac accessories.
You can even get creative and make a little box with a rubber flap that falls down and is open when the engine is running and no air coming from the leaf blower so it sucks air not through the tubing and not through the leaf blower but in reality that's not really a problem because most leaf blowers will flow just fine and don't restrict the flow at all.
This way though when you pressurize the air filter intake and stuff with the leaf blower it will soft close the little box flap so the only air coming through is coming from the leaf blower with the gasoline mixture.

The problem is you really can't give it that much volume until you get up to pretty high engine speeds but if you had a situation where you kept the engine at constant RPMs or even if you eliminated the governor like many race engines do you could get it adjusted pretty decently.


#36

R

rdedrick

wineman said:
It is a Murray walk behind mower and the grass is very thick and the mower sometimes has trouble getting through it. I have received numerous suggestions to add a turbocharger and get rid of the muffler. I have been told with this being an OVC that it will double the power and that the muffler is taking away power.

Sharpen the blade and narrow your cut. Or buy a bigger mower.
Click to expand...


#37

Hammermechanicman

Hammermechanicman

Back in a previous century when the 5hp flathead briggs was THE engine guys running the unlimited class were running superchargers and alcohol. Some were centrifugal and some axial flow. Usually a belt drive off the crank. Pretty much aftermarket for everthing but the block, crank and flywheel. They made crazy power.


#38

W

wineman

Chipg1956 said:
torque x RPM / 5251.1 =HP
In order to add a turbo you would need to also add some sort of pressurized oiling system. I am guessing that the kits you showed are for larger engines.
Click to expand...
They said to use 90W differential oil and everything would be fine.


#39

W

wineman

Mike88se said:
I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.
Click to expand...
I am going to work on it today and will report back.


#40

W

wineman

Mike88se said:
I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.
Click to expand...
They said that using an octane booster will also be part of the deal.


#41

B

bertsmobile1

Chipg1956 said:
torque x RPM / 5251.1 =HP
In order to add a turbo you would need to also add some sort of pressurized oiling system. I am guessing that the kits you showed are for larger engines.
Click to expand...
Yes I forgot to add the fudge factor because I was not trying to put in an equation, just to show that you can drastically increase theHp simply by making the engine run faster
The down side is a governed mower should be running just past the peak torque revs , thus as you load the engine the torque ( which is what does the work ) comes into play to help the engine recover .
Go too far past peak torque and the curve flattens out so not much extra torque to help it recover.
Japanese buzz boxes are the perfect example where you need to change back all the time in order to accelerate under load .


#42

W

wineman

Mike88se said:
I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.
Click to expand...
Well, I got everything together this morning. It took 4 hours to do. I was told that I may have to use some starter fluid first, but did not and it started right up. This is the sequence of what happened.
It started with a much louder engine and then some alternating low and very high pitched sounds. The mower was shaking violently and the blade seemed to be running a much higher rpm. Then all of a sudden the engine seemed to surge even more (it would not not turn off no matter what I did) and I heard a bang. It stopped running and blue smoke cam out along with it dumping of oil and then I smelled gas and went to the other side of the house for safety reasons, heard another loud pop and the entire mower was covered in gas and flames. I got the fire put out and figured it probably would not run again. It blew pieces of the engine out a few feet and 2 of the bolts that hold the engine in had been broken.

Do any of you have a suggestion as to what I might have done wrong in the assembly.


#43

W

wineman

TobyU said:
It's absolutely silly and absurd for anyone to be interested in this kind of thing for a lawn mower that's actually used to cut grass.
Even the current horsepower ratings we have, even though they're kind of a joke and erroneously high, still have far more power than we need to cut our lawns!

The only thing I can see this being worthwhile for are the play toys and race or pulling mowers people do.
This is not some makeshift play around kit but a real turbocharger and would certainly give huge power increases but it also would come with other complications with tuning and then with exhaust etc but I'm assuming anyone wanting to build this kind of power for pulling purposes etc is using a custom exhaust of a very large size or rather a dump and using the size to help tune exhaust scavenging etc.

Now in the play around version of Turbo charging lawn mower I've done that several times just for fun.

The quickest and easiest way has always been with a leaf blower but you can also use anything where you have a controlled or consistent flow of air like a shop vac exhaust or compressed air etc.
All you have to do is add an extra fuel source

So you take your handheld leaf blower whether it be gasoline or a battery powered one and then you drill you a hole somewhere around 8 in from the end of they discharged tube there where the air comes out and you pipe you a little hose brass fitting spray tip nozzle etc into there.
You need Subway to control the size of the bottom like a fixed orifice etc but many things can be adapted.
Then you run you a piece of tubing, preferably clear so you can see the fuel flow to a fuel tank source and when you blow the air out the blower it will suck the fuel out and you can adjust everything just right with your speed and with the orifice size so you're blowing a gasoline enriched mixture of air coming out of the end.
Now of course you can take this makeshift design a little further and turn it into a flamethrower too but none of it is very safe.

So you just pipe the leaf blower into the intake with various plastic hose and adapter assemblies like PVC or Shop-Vac accessories.
You can even get creative and make a little box with a rubber flap that falls down and is open when the engine is running and no air coming from the leaf blower so it sucks air not through the tubing and not through the leaf blower but in reality that's not really a problem because most leaf blowers will flow just fine and don't restrict the flow at all.
This way though when you pressurize the air filter intake and stuff with the leaf blower it will soft close the little box flap so the only air coming through is coming from the leaf blower with the gasoline mixture.

The problem is you really can't give it that much volume until you get up to pretty high engine speeds but if you had a situation where you kept the engine at constant RPMs or even if you eliminated the governor like many race engines do you could get it adjusted pretty decently.
Click to expand...
Well, I got everything together this morning. It took 4 hours to do. I was told that I may have to use some starter fluid first, but did not and it started right up. This is the sequence of what happened.
It started with a much louder engine and then some alternating low and very high pitched sounds. The mower was shaking violently and the blade seemed to be running a much higher rpm. Then all of a sudden the engine seemed to surge even more (it would not not turn off no matter what I did) and I heard a bang. It stopped running and blue smoke cam out along with it dumping of oil and then I smelled gas and went to the other side of the house for safety reasons, heard another loud pop and the entire mower was covered in gas and flames. I got the fire put out and figured it probably would not run again. It blew pieces of the engine out a few feet and 2 of the bolts that hold the engine in had been broken.

Do any of you have a suggestion as to what I might have done wrong in the assembly.


#44

Mike88se

Mike88se

wineman said:
I am going to work on it today and will report back.
Click to expand...
Okay, should be interesting.

wineman said:
They said that using an octane booster will also be part of the deal.
Click to expand...
Might be best to just buy some race gas. I say you still need an oil pump. Among other things ;) I looked at your link. Uness I missed seeing it, the site doesn't give any specs on the turbo except "100hp" so you really don't know what you're getting in terms of compressor size, wastegate (the thing that controls when to dump boost to prevent your piston(s) from becoming missiles) setting etc.
So add a manual boost controller and boost gauge to your parts list just in case you do get enough exhaust to move the turbine. Which I don't think you will bc that turbocharger is just too damned big for your lawn mower. I don't recall you posting the displacement or air volumetrics (is that a word?) but I do recall you saying it's a Murray so at least you won't be blowing up a good mower. J/K ;)
wineman said:
They said to use 90W differential oil and everything would be fine.
Click to expand...
Ok (altho 90w oil sounds crazy) but where are you running the oil supply & return lines? To the crankcase obviously but the question is how are you going to get oil to flow through the supply line to the turbo? I see they have banjo fittings and oil feed flanges for sale but gravity is not your friend here.Oil is not going to voluntarily run up the supply line to the turbo bearings. There's so many problems with this idea that I don't even know where to go next so I'll just recommend you read the second review at the link on that site to Amazon. That is what is going to happen with a $140 turbocharger in a best case scenario. It seems like nitrous oxide would be easier and more likely to work but you'd still need more fuel. NOS got a bad rep from people who didn't know how to use it plus those silly Fast & Furious movies. It's actually good when used properly.
At any rate I'll say good luck and hope to get email notifications of the results.


#45

W

wineman

Mike88se said:
Okay, should be interesting.


Might be best to just buy some race gas. I say you still need an oil pump. Among other things ;) I looked at your link. Uness I missed seeing it, the site doesn't give any specs on the turbo except "100hp" so you really don't know what you're getting in terms of compressor size, wastegate (the thing that controls when to dump boost to prevent your piston(s) from becoming missiles) setting etc.
So add a manual boost controller and boost gauge to your parts list just in case you do get enough exhaust to move the turbine. Which I don't think you will bc that turbocharger is just too damned big for your lawn mower. I don't recall you posting the displacement or air volumetrics (is that a word?) but I do recall you saying it's a Murray so at least you won't be blowing up a good mower. J/K ;)

Ok (altho 90w oil sounds crazy) but where are you running the oil supply & return lines? To the crankcase obviously but the question is how are you going to get oil to flow through the supply line to the turbo? I see they have banjo fittings and oil feed flanges for sale but gravity is not your friend here.Oil is not going to voluntarily run up the supply line to the turbo bearings. There's so many problems with this idea that I don't even know where to go next so I'll just recommend you read the second review at the link on that site to Amazon. That is what is going to happen with a $140 turbocharger in a best case scenario. It seems like nitrous oxide would be easier and more likely to work but you'd still need more fuel. NOS got a bad rep from people who didn't know how to use it plus those silly Fast & Furious movies. It's actually good when used properly.
At any rate I'll say good luck and hope to get email notifications of the results.
Click to expand...
Well, I got everything together this morning. It took 4 hours to do. I was told that I may have to use some starter fluid first, but did not and it started right up. This is the sequence of what happened.
It started with a much louder engine and then some alternating low and very high pitched sounds. The mower was shaking violently and the blade seemed to be running a much higher rpm. Then all of a sudden the engine seemed to surge even more (it would not not turn off no matter what I did) and I heard a bang. It stopped running and blue smoke cam out along with it dumping of oil and then I smelled gas and went to the other side of the house for safety reasons, heard another loud pop and the entire mower was covered in gas and flames. I got the fire put out and figured it probably would not run again. It blew pieces of the engine out a few feet and 2 of the bolts that hold the engine in had been broken.

Do any of you have a suggestion as to what I might have done wrong in the assembly.


#46

C

CraigH

wineman said:
Well, I got everything together this morning. It took 4 hours to do. I was told that I may have to use some starter fluid first, but did not and it started right up. This is the sequence of what happened.
It started with a much louder engine and then some alternating low and very high pitched sounds. The mower was shaking violently and the blade seemed to be running a much higher rpm. Then all of a sudden the engine seemed to surge even more (it would not not turn off no matter what I did) and I heard a bang. It stopped running and blue smoke cam out along with it dumping of oil and then I smelled gas and went to the other side of the house for safety reasons, heard another loud pop and the entire mower was covered in gas and flames. I got the fire put out and figured it probably would not run again. It blew pieces of the engine out a few feet and 2 of the bolts that hold the engine in had been broken.

Do any of you have a suggestion as to what I might have done wrong in the assembly.
Click to expand...
That has to be one of the best posts of the year right there!

@wineman have you got any pics of the setup at all? Or any info on the parts used?


#47

Mike88se

Mike88se

wineman said:
Well, I got everything together this morning. It took 4 hours to do. I was told that I may have to use some starter fluid first, but did not and it started right up. This is the sequence of what happened.
It started with a much louder engine and then some alternating low and very high pitched sounds. The mower was shaking violently and the blade seemed to be running a much higher rpm. Then all of a sudden the engine seemed to surge even more (it would not not turn off no matter what I did) and I heard a bang. It stopped running and blue smoke cam out along with it dumping of oil and then I smelled gas and went to the other side of the house for safety reasons, heard another loud pop and the entire mower was covered in gas and flames. I got the fire put out and figured it probably would not run again. It blew pieces of the engine out a few feet and 2 of the bolts that hold the engine in had been broken.

Do any of you have a suggestion as to what I might have done wrong in the assembly.
Click to expand...
much louder engine: no muffler
Turbos make high pitched sounds... maybe you actually got it to spool up
The oil? Where was it coming from?
The gasoline... if the turbo spooled high enough then it got very very hot. I've seen them get glowing red hot. Might have melted the gas tank if it was plastic... or maybe the fuel hose. If it's any consolation your project was more successful than I expected... sort of.
I imagine you had a lot of predetonation... piston is probably toast
Mostly it sounds like what people here expected to happen... happened. Now you can get a better lawn mower :) I'd recommend a used Honda. They're usually reliable but parts are cheap, they're easy to work on, and it's a good time of year to find a deal on one, unless there's a lot of trees in your area in which case people may be using them to bag leaves which is something they're very good at.

This>>>>
CraigH said:
have you got any pics of the setup at all?
Click to expand...


#48

T

ToniG

Do any of you have a suggestion as to what I might have done wrong in the assembly
Click to expand...

Not having a kill switch/fuel shutoff (or an inlet strangle). I do hope there is a video, it could be useful.
As you learned, Don't have much fuel in the tank.
To have any chance of success( just getting it to run ok) in this type of experiment you need to do a lot of thinking, research & learning. Listen to advice from the experienced.
Analise results of the failure, one obvious point being over-speed = bang. (wasn't that advised...)

If you did get to the stage where you had usable control of the engine with increased RPM/power it will be short lived. Maybe should wear motocross boots.
Most modern mower engines are the opposite to "bullet proof", there is little or no headroom for "increased power & reliability". You can't have both in this situation.
So good on you for doing something interesting but do expect to fail in the original goal to cut Harder-Longer.
I have fails in my experiments & its part of the learning.
At least you can fallback to a bit bigger engine after the smoke settles, this has a good chance of success.

I had an old 8hp B&S powered walk behind mower that was bogging down with tall seteria grass, I made a longer exhaust pipe with a free-flow silencer (perf-tube with glass fiber packing), re-tuned & the mid RPM power increase was now adequate for the job.


#49

Hammermechanicman

Hammermechanicman

Need a pic of the engine with the turbo on it and a link to where you bought it from.


#50

B

bertsmobile1

I expect when he has a good look the rod will be poking out through a nice new window in the crankcase
Would not turn off is most likely because the spark plug was now red hot which allowed the engine to continue running but way out of time because the charge would detonate as soon as it got to a combustable Air:Fuel: compression ratio
next time take a video and put it on You Tube people like to see engines blowing up and who knows you might even make $ 4.95 in royalties .
We did try to warn you .


#51

Hammermechanicman

Hammermechanicman

Still waiting on pics
🤔


#52

W

wineman

bertsmobile1 said:
I expect when he has a good look the rod will be poking out through a nice new window in the crankcase
Would not turn off is most likely because the spark plug was now red hot which allowed the engine to continue running but way out of time because the charge would detonate as soon as it got to a combustable Air:Fuel: compression ratio
next time take a video and put it on You Tube people like to see engines blowing up and who knows you might even make $ 4.95 in royalties .
We did try to warn you .
Click to expand...
Very correct the spark plug did turn red hot. I am not sure about enjoying seeing things blowing up. We have enough of that going on around the world as it is.

But you were correct. As soon as I smelled gas I got away from it quite quickly and hid around a corner.


#53

L

lizford

After reading this complete thread, I still cannot take this story seriously.
It sounds more like someone trying to make a joke and the forum is the punch line.
If someone appears to have the ability to install a turbocharger on this lawn mower, why would they not have the common sense to know it wouldn't work. (Scratch that, we have a lot of those people walking among us.)
Why not just raise the mower deck to help alleviate the problem? A more powerful engine will not help if there is no where for the grass to go.
Why are there no pictures or videos?
PIctures can be taken of the aftermath. I call BS.


#54

M

minipower

wineman said:
Have any of you used any of the following and what were the results?

www.outdoorpowerllc.net

Boosted Mowers. Lawn Mower Turbo Kit

If you're looking for a way to boost the performance of your lawn mower, a turbo kit is the perfect solution. With the right kit, you can increase horsepower, improve fuel efficiency, and get a cleaner, healthier lawn. Fortunately, Amazon offers a wide selection of lawn mower turbo kits that are...
www.outdoorpowerllc.net www.outdoorpowerllc.net

Thanks
TBB
Click to expand...
I haven't done this. It's just an idea I've had. Do remember in the 1980's american cars having smog pumps ? They were used to pump air into the exhaust manifolds to trigger burning the left over fuel inside the exhaust system.
My idea is to use the pump and a supercharger on these relatively small engines. The problem is I have not been able to find info on the cfm the pump blows or the working rpm ranges.


#55

Hammermechanicman

Hammermechanicman

lizford said:
After reading this complete thread, I still cannot take this story seriously.
It sounds more like someone trying to make a joke and the forum is the punch line.
If someone appears to have the ability to install a turbocharger on this lawn mower, why would they not have the common sense to know it wouldn't work. (Scratch that, we have a lot of those people walking among us.)
Why not just raise the mower deck to help alleviate the problem? A more powerful engine will not help if there is no where for the grass to go.
Why are there no pictures or videos?
PIctures can be taken of the aftermath. I call BS.
Click to expand...
I was trying to be nice about questioning things and I find the description of the result suspect. So at this point I will assume my first thoughts were correct and I agree with you. BS.


#56

C

CraigH

@wineman is there a reason you seem to not want to post any pictures or info on this?
I'm genuinely curious about how you had it set up to make it work and would love to see some pictures or even a video of it if you took a video of it running?


#57

L

lbrac

Was there any entertainment value to this inquiry and subsequent thread?


#58

A

aussielawny

Best thread l've read in ages :D


#59

EatPreyMow

EatPreyMow

lizford said:
After reading this complete thread, I still cannot take this story seriously.
It sounds more like someone trying to make a joke and the forum is the punch line.
If someone appears to have the ability to install a turbocharger on this lawn mower, why would they not have the common sense to know it wouldn't work. (Scratch that, we have a lot of those people walking among us.)
Why not just raise the mower deck to help alleviate the problem? A more powerful engine will not help if there is no where for the grass to go.
Why are there no pictures or videos?
PIctures can be taken of the aftermath. I call BS.
Click to expand...
Had to check back in on this thread and after reading it again I must agree with @lizford. For it to blow up on the first start is suspect, but the biggest tell is the lack of photos. No way would he try out a turbo kit and fail to have his phone at hand for the first start.

That said, if I had money to burn it would be fun to try a turbo kit, but then if I'm going to do that then why not get a old Miata to tinker with? A lawnmower doesn't get more fun with a turbo, it only grows more expensive.


#60

C

Chipg1956

You can pretty much assume that the weakest part of most small engines is the connecting rod. If you find it interesting to read about high performance small engines, try here: https://4cycle.com/karting/


#61

B

bertsmobile1

Chipg1956 said:
You can pretty much assume that the weakest part of most small engines is the connecting rod. If you find it interesting to read about high performance small engines, try here: https://4cycle.com/karting/
Click to expand...
Yep 5000 rpm and bang no rod
Mowers with pressure fed big ends can go a bit higher but usually the little end simply snaps off

When doing racing mower engines, the rods have to be changed unless you are just runny one for the kids to play with


#62

Moparjoe499

Moparjoe499

wineman said:
Have any of you used any of the following and what were the results?

www.outdoorpowerllc.net

Boosted Mowers. Lawn Mower Turbo Kit

If you're looking for a way to boost the performance of your lawn mower, a turbo kit is the perfect solution. With the right kit, you can increase horsepower, improve fuel efficiency, and get a cleaner, healthier lawn. Fortunately, Amazon offers a wide selection of lawn mower turbo kits that are...
www.outdoorpowerllc.net www.outdoorpowerllc.net

Thanks
TBB
Click to expand...
For what reason would anyone want to spend money on a turbo kit when the engines on today's mowers are reaching close to 30 horses for a riding mower. After that one could invest in a utility tractor with 40 horses and a 5 to 6 foot mower with a 3 point hitch or a pull behind finish mower. You are only asking for trouble when putting a turbo kit on a riding mower engine. These riding mower engines are that cheap made in china crap that barely last 5 years and someone wants to add a turbo to throw the rods. Good luck with a turbo, you are only asking for trouble.


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