Need some torque specs

[FarmGeezer]

I'll take that advise to heart and re torque the gaskets. Thanks for your help.

Regards,

FarmGeezer

 

[bertsmobile1]

The very first thing is we need the make and model of the engine you are working on. This is the reason no one give you any specs. I am going to take a guess here and say you have metric bolts??? To get a torque specs we will need the proper bolt size not the wrench size. If you have 5/8 fine thread bolts holding that head down its something I have never come across in my years in the trade and you would be looking at 150 ft. lbs. or better. By any chance do you have a 20HP Briggs and Stratton in this mower? Toque bolts in two increments, first 200 in. lbs. and then 370 in lbs. This is just guessing as to what you have.

Not meaning to nit pick but the 150 ft lbs is of course 150 inch pounds which should be obvious from the latter two figures which are both inch pounds

 

[reynoldston]

Not meaning to nit pick but the 150 ft lbs is of course 150 inch pounds which should be obvious from the latter two figures which are both inch pounds

I have no idea what you are talking about here. I got my information off a torque chart. A 5/8 bolt is what I would call a large bolt for a lawn mower engine head bolt. They would use something like that on a large diesel engine head bolt. For a standard steel coarse thread 5/8-11 bolt grade 5 bolt my chart calls for 154 foot pounds of torque not inch pounds but if you need it in inch pounds that will come to 1,848 inch pounds.

 

[FarmGeezer]

The head bolts in question are metric . I used the 5/8 by mistake. A closer size in SAE would be 3/8's. The head bolt size is 13mm.

Somebody needs a nap...imho

Regards,

Farmgeezer

 

[mechanic mark]

https://www.briggsandstratton.com/us/en/support/manuals/results?NTT=351777-0036* engine operators manual & parts list

http://rich.homeunix.com/gravely/pro16/272144 Vanguard Twin Cylinder OHV BRIGGS & STRATTON.pdf engine service repair manual. Head bolt torque is 165 inch lbs. page 166 in manual.

 

[FarmGeezer]

Mechanic Mark, Thank you for your help.

Regards,

FarmGeezer

 

[bertsmobile1]

I have no idea what you are talking about here. I got my information off a torque chart. A 5/8 bolt is what I would call a large bolt for a lawn mower engine head bolt. They would use something like that on a large diesel engine head bolt. For a standard steel coarse thread 5/8-11 bolt grade 5 bolt my chart calls for 154 foot pounds of torque not inch pounds but if you need it in inch pounds that will come to 1,848 inch pounds.

From your previous post

If you have 5/8 fine thread bolts holding that head down its something I have never come across in my years in the trade and you would be looking at 150 ft. lbs. or better. By any chance do you have a 20HP Briggs and Stratton in this mower? Toque bolts in two increments, first 200 in. lbs. and then 370 in lbs. This is just guessing as to what you have.

The first number you quote is 150 ft lbs
You then say to torque to 370 inch pounds in two steps.

Me thinks the numbers you have looked up were for fine threads into cast iron or steel.
Threads in die cast aluminium will shear out way before you torque a bolt to 150 ft lbs and that is irrespective of the thread size or form.

As a rule of thumb bolts into alloy should never be torqued past 45 ft lbs ( 540 inch lbs )

 

[reynoldston]

Me thinks the numbers you have looked up were for fine threads into cast iron or steel.
Threads in die cast aluminium will shear out way before you torque a bolt to 150 ft lbs and that is irrespective of the thread size or form.

Yes I agree on this, but the OP was way off on his bolt sizes. First of all he was working with metric not SAE. You might have a lot of different things down under that I never come across but when he was talking about 5/8 size head bolts the first thing that come to me was it was something I have never seen in a lawn mower. I have been in the trade too long to say it isn't true because anytime you do it backfires into your face when you don't know what. As I said when I did give any torque specs I was just making a guess. 1 ft. lb. is 12 in lbs. is the way I always worked with it. 12 inches to a foot over here in the USA.

 

[FarmGeezer]

Well I got the gasket kit today ( $50.00 ). Did a valve job and everything is ready for reassembly. My heads had valve guide seals on both valves. The kit only comes with 2 . I assume they go on the intake valve guides. I plan on reassembly on Thursday ( my day off ). Could someone please advise me on the placement of the new Valve stem seals.

Thanks,

FarmGeezer

 

[Pumper54]

FarmGeezer

Read this section, it should help you: http://rich.homeunix.com/gravely/pro16/272144 Vanguard Twin Cylinder OHV BRIGGS & STRATTON.pdf

Tom