Toro time cutter SW5000 Head bolt torque specs

[Reverett]

I'm a new user here and having trouble finding the torques specs for a Toro V-Twin 24.5HP engine. It is a Toro model 74790 engine Serial number above 315xxxxxx and below 316xxxxxx Specs I have found says 38 FT Lbs but I know that cannot be correct. Looking at the similar Briggs specs they say 220ft lbs which sounds more like it.

Has anyone out there got any experience with this engine? Thanks for any help!

 

[MParr]

I see 38 pound feet too.

 

[Reverett]

I see 38 pound feet too.

When I went to remove the head bolts with a 1/2 impact wrench set at 150 PSI, they wouldn't budge. Had to use a breaker bar to loosen them. They had to be above 180 ft lbs. Does anyone have the head bolt torque specs for a v-twin 24-25hp Briggs, Kawasaki and Kohler? I figure they will all be similar and I will get them to that range. I'm afraid if I only go to 38Ft lbs I will blow the head gaskets

 

[MParr]

When I went to remove the head bolts with a 1/2 impact wrench set at 150 PSI, they wouldn't budge. Had to use a breaker bar to loosen them. They had to be above 180 ft lbs. Does anyone have the head bolt torque specs for a v-twin 24-25hp Briggs, Kawasaki and Kohler? I figure they will all be similar and I will get them to that range. I'm afraid if I only go to 38Ft lbs I will blow the head gaskets

Kohler Small Engine Head Torques

outdoorpowerinfo.com

So, 38 pound feet is probably correct for the Loncin engine. It lists 10mm x 1.25 bolts so, it cannot be 180 pound feet.
I hope that you are using new bolts of the correct grade.

 

[Hammermechanicman]

180 ft lb in an aluminum block???

 

[MParr]

180 ft lb in an aluminum block???

I know! 150 ft.lb. is the torque spec on the lug nuts of my F-150.
The book says 38 ft.lb.
A 10mm bolt is about the same size as a 5/16” bolt.

 

[StarTech]

That Briggs torque head torque would be 220 in/lbs not 220 ft/lbs.

 

[Reverett]

Thanks guys! I wasn't taking into consideration the aluminum block and bolt size and only what it took to remove the bolts. But the bolts were probably oxidized to the block making them seem tighter than they were. I'll use the 38 Ft lbs and see what happens. Just didn't seem right! And yes, replacing the bolts with factory part numbers.

 

[bertsmobile1]

38Nm is 28ft lb which is on the high side for a coarse thread zinc plated bolt into aluminium castings
38 ft lbs will strip the thread out of the hole
So I will guess that the translator forgot to convert the Nm figure as used in China to Ft lbs as used in the USA.
Break away torque is not a reliable measure of original bolt tension and this is very much the case with steel into aluminium as a very tiny amount of galvanic corrosion massivly increases the friction between the bolt & the hole unless the bolt is lubricated with a seizure preventative .
There are thousands of torque charts on the web that list torques per bolt diameter & thread profile in different materials

And anything over 50 ft lbs into an Al-Si castingwill strip the threads out of the hole for any bolt under 3/4" diameter
The B & S specs are INCH POUNDS and are used to imply a very accurate calibrated tension wrench is required because a 220inlb would be +/- 0.5 inlbs and that is the sort ot torque you caouls apply with your fishing tackle ( to be polite )

 

[MParr]

@Reverett listen to @bertsmobile1 .