Intec 12.5 Vertical

[Knots]

Intec 219802 type 0117E1
I checked one other thing on this engine. The air filter and breather box are both dry and clean. About the crankcase breather in this engine, can anyone tell me where it is located? Might as well check it before I pull head and spend $50.00 on gaskets.
Many thanks to all who have responded.
Much appreciated!

Knots

 

[StarTech]

Under the flywheel according to the IPL.

 

[bertsmobile1]

What about a bad or a broken ring? Or scored cylinder walls? I've seen a few weird cases where the engine has compression to run but has terrible blow-by

And you put it right.
"weird"
Yes there are other causes but about 90% of the times it will be a head gasket .
Then around 9 % of the time it will be a breather
the final 1% is "other causes"
So we start with the obvious and then move to the obscure
When the head is off you can inspect the bore for cross hatching / scoring etc

It is an intek engine which is renown for blowing head gaskets
I keep about 30 in stock because I am forever changing them and the warehouse regularly runs out of them in the middle of the season
And for repeat performers I have some solid copper ones because despite lapping they just keep on blowing .
It is fundamentially bad design , copied from Vanguard but cheapened .
There is not enough clamping force on the bridge region between the bore & the push rod tunnel
So either then bolts need to be moved in, another bolt added or the bridge needs to be wider .
B & S's answer was to rough cut the surfaces with a fly cutter so the clamping faces are rough & hold the gasket tighter
Some times it works and some times it does not work .

 

[VRR.DYNDNS>BIZ]

Nope. I have never used that before and I don't think briggs recommends any sealants. Before we do call it on the head gasket though, did you make sure it isn't just overfilled with oil or something simple? Typically blown head gaskets will cause engine smoking and there will be fumes coming out of the dipstick if you take it out after the engine has been running for a while.

Even a dirty air filter, and a few more like bad breather. Head gasket need to be proven in my thinking.

 

[VRR.DYNDNS>BIZ]

And you put it right.
"weird"
Yes there are other causes but about 90% of the times it will be a head gasket .
Then around 9 % of the time it will be a breather
the final 1% is "other causes"
So we start with the obvious and then move to the obscure
When the head is off you can inspect the bore for cross hatching / scoring etc

It is an intek engine which is renown for blowing head gaskets
I keep about 30 in stock because I am forever changing them and the warehouse regularly runs out of them in the middle of the season
And for repeat performers I have some solid copper ones because despite lapping they just keep on blowing .
It is fundamentially bad design , copied from Vanguard but cheapened .
There is not enough clamping force on the bridge region between the bore & the push rod tunnel
So either then bolts need to be moved in, another bolt added or the bridge needs to be wider .
B & S's answer was to rough cut the surfaces with a fly cutter so the clamping faces are rough & hold the gasket tighter
Some times it works and some times it does not work .

I believe since your bulk order of gaskets a gasket change has been made.

 

[artemjemmy]

Even a dirty air filter, and a few more like bad breather. Head gasket need to be proven in my thinking.

I test for head gasket leaks using a cylinder leakdown tester with the valve cover off, then try to feel a air current from the cylinder to the pushrod cavity. I bet if you had a smoke machine or something it would work even better.

 

[artemjemmy]

And you put it right.
"weird"
Yes there are other causes but about 90% of the times it will be a head gasket .
Then around 9 % of the time it will be a breather
the final 1% is "other causes"
So we start with the obvious and then move to the obscure
When the head is off you can inspect the bore for cross hatching / scoring etc

It is an intek engine which is renown for blowing head gaskets
I keep about 30 in stock because I am forever changing them and the warehouse regularly runs out of them in the middle of the season
And for repeat performers I have some solid copper ones because despite lapping they just keep on blowing .
It is fundamentially bad design , copied from Vanguard but cheapened .
There is not enough clamping force on the bridge region between the bore & the push rod tunnel
So either then bolts need to be moved in, another bolt added or the bridge needs to be wider .
B & S's answer was to rough cut the surfaces with a fly cutter so the clamping faces are rough & hold the gasket tighter
Some times it works and some times it does not work .

Yup, there really needs to be a bolt in the bridge between the cylinder and pushrod cavity. For those engines that keep blowing head gaskets, do you check if the head is warped? You can use a machinists straight edge or a piece of plate glass and place the head on it and try to fit feeler gauges to check for warpage.

 

[bertsmobile1]

At a rough guess I would do 20 or so intek gaskets a season.
If you are suggesting I swap gaskets just because I can then you have no idea of the way I work.
Nothing gets replaced unless it needs to be replaced thus I use about 50 spark plugs a year and about 30 fuel filters a year .
That is against around a 300 job average year .
The only real proof is to pull the head & check and in doing this you destroy the gasket so it is a moot point.
Excessive crankcase pressure is either charge leaking in or the breather blocked.
A blocked breather, can easily be checked with a damp finger over the end of the tube, takes about 2 minutes
Leaking inlet valve seals & bad rings can be checked by working the throttle with your finger & watching / listening.
You also pick up blown gaskets this way as well because the engine will faulter on initial acceleration as it will be sucking in crankcase fume rather than fuel then steady out when the speed has been maintained .
If the gasket was not at fault then the customer gets it done for free.
I believe it stems from a casting fault as some will run 1000 hours without problems while others will do a gasket a season from new .
Usually I can diagnose a blown gasket by the sound the engine makes when it starts then the way it sounds when the blades are engaged .
Now I could spend an full hour doing a dozen thests to confirm the gasket leak or 1/2 hour to replace the the gasket if all goes well .

Crankcases are cast on a multi head machine so one bad mould can affect as few as 1 in 100 castings depending upon the size of the machine.
Or it could be because they are not scrapping the first couple of rotations which are needed to get the machine & channels up to working temperature .
Tossing ingots into the melt pot in too large a batch can also cause temperature problems that will cause flow problems.
Had a "materials fault" at one time that was actually a lack of forklifts problem .
The driver would put 10 pallets ( stacks actually ) of ingots in front of the machine which was around a full shifts worth
Th ingots from the first 2 stacks , sat on the side for the regulation 3 minutes to pre warm & drive off water then got shoved in
As the stacks got further away the furnace man started to get behind so a lot of them were dropped directly into the furnace which drops the temperature which slows down the flow so you end up with porus castings because the parts of the casting solidifies & blocks off the feeder sprews before the entire casting has solidified leaving internal voids .

 

[bertsmobile1]

Yup, there really needs to be a bolt in the bridge between the cylinder and pushrod cavity. For those engines that keep blowing head gaskets, do you check if the head is warped? You can use a machinists straight edge or a piece of plate glass and place the head on it and try to fit feeler gauges to check for warpage.

Standard Operating proceedure as a in a lot of cases they have been leaking for a very long time and the bridge is erroded

 

[artemjemmy]

Here this particular gasket design doesn't present itself as smoker most times here in my shop. I had one engine that burned one quart per 1/2 gallon of fuel and the only thing that was apparent while mowing was a smell of oil burning. Many modern oils don't smoke near as much as older oils did either. Most times the only indication of a blown head gasket is loss of oil volume and oil present in the air cleaner side of the carburetor. Now the fuel pump vent does sometimes have oil leaking out of it too.

Any engine using this particular gasket design that comes into my shop for the first time get a leak down test done to check the head gasket condition.

This particular head gasket design to prone to blowing between the cylinder and the push rod galley. While replacing head gasket make sure the head is not warped.

Also torque the head screws [bolts] to 20.8 fl/lbs [250 in/lbs] using three step torque method [1/3, 2/3, and Full] and in the proper torquing pattern [see below image]. This is the current torque specs for these gaskets and not what the chart says that is being passed around that specs 18.3 ft/lbs [220 in/lbs]. By going to 25 ft/lbs you risk aluminum thread pull out when the engine reaches full operating temperature. Also going to full torque all at once risks warping the head. Heads are not cheap. This head was $212 the last time I checked.

View attachment 59190

Valve clearance is .004-.006" for both intake and exhaust rockers. Rocker Jam Nut or set screw torqued 45 lb-in. Rocker cover screws [bolts] are torque to 65 in/lbs. Note some of these covers are mounted with RTV instead of a paper gasket. Both ways are acceptable. It just that RTV is less likely to leak when applied properly.

Personally I use the RTV method but I have the surface prep / accelerator chemical and know not to allow oil contact for at least 12 hrs. Also when the RTV is applied, screws are only tighten finger tight for at least 12 hrs, then the rocker cover is torque to final torque. I know it time consuming but it is what works here for leak proof application. The 30 minutes cure time on the product tube just don't work in a near airless application. Even at 12 hrs some uncured liquid squeeze out happens.

Yes, I don't find these engines to smoke too bad when they do blow head gaskets, but they do usually smoke more than normal, especially once they are hot. The customer complaint is usually that the engine is smoking when they do blow a gasket.