K341 head

[CochinsRus 0]

I installed my new head gasket today and I know it said to torque to 25-30 ftlbs but will it hurt to go to 35 ftlbs.

[chevy030303 0]

it mit brake your hand bolts

[rmaynard 14,898]

I'd keep it within the limits established by the manufacturer. Too much torque can strip threads, or crack heads.

Bob

[rickv1957 70]

Your head will seal fine at factory specs as long as surface is true,Rick

[Cody 269]

According to the kohler rebuild manual the head should only be torqued to 16-18 ft pounds, if it doesnt seal at that torque, most likely either your head or block is un-true

[TT-(Moderator) 1,127]

According to the kohler rebuild manual the head should only be torqued to 16-18 ft pounds

The illustration in the Kohler TP-2379 manual shows 25 - 30 ft. lbs.

Standard torque settings (when not specified) for a 3/8-16 grade 5 bolt is 35 ft. lbs. and would be fine for the head bolts if your torque wrench doesn't have a lower setting.

(is that why you asked?)

The most important thing is to tighten all bolts equally (whether 30 or 35 ft. lbs.) in the correct pattern, run the engine long enough to reach operating temperature, allow it to cool down completely, and retorque the bolts again.

[Save Old Iron 1,563]

torque wrenches are typically less accurate at their lowest and highest settings

a wrench is calibrated to be less than 5% variance near its middle range but could easily exceed that on its lowest and highest settings within its range

so if all you have is a wrench with a low range of 35 ft lbs - it COULD be off by 10% and the 35 ft setting could be as high as 39 ft lbs and still be "calibrated"

39ft lbs is nearly 50% higher than the midrange of the recommended torque spec.

maybe if you commented on why you wanted to exceed the manufacturer's spec's - we might have a better answer.

[CochinsRus 0]

It just seemed that when I torqued it down it didn't take much pressure to get it to that 30 lb point. I just feel more comfortable going an extra few ftlbs. The way I feel is that when you use a torque wrench the when you hit that ftlb mark then when pressure is let off the wrench you will have a little flex back on the bolt head. And plus I don't feel that you will get an accurate torque since there is friction between the treads on the bolt and the block. I just want to make sure it seals good.

[Duff 206]

It just seemed that when I torqued it down it didn't take much pressure to get it to that 30 lb point.

I'm no mechanic but I thought the same thing when I was working on my M12. Then I realized that the handle on my torque wrench is about twice as long as my regular ratchet handle so I was getting much more mechanical advantage as I torqued the bolts. Naturally, this would "feel" like the bolts were tightening too easily. With that in mind I stayed with 25 ft-lbs. and do plan on retorquing after I've had a chance to heat up the engine. JMHO......

Duff B)

[Save Old Iron 1,563]

take a look to see if your torque wrench accuracy is rated as a percentage of the full scale indication or if it is rated for "indication" accuracy

full scale accuracy - lets say 5% - would be 5% of 100 ft lbs for a 100 ft lb wrench - so any setting on the wrench could be off by 5 ft lbs

indication accuracy is rated as 5% of the indicated setting - so 5% of 30 ft lbs would be 1.5 ft lbs - a significant difference

if you feel too much torque is need to get the bolts to travel down into the head use a bottom tap to chase and clean threads, usually about $15 to buy.

A quick wire brushing of the head bolt threads may help if someone applied a sealant on previous attempts to tighten the bolts - the threads should be clean and dry when using manufacturer's torque recommendations

tightening down a K head at 30 ft lbs is not a chore most people would grunt doing. not like tightening a gland nut on a VW flywheel - tell you what !!

[mrfixit82852 3]

It just seemed that when I torqued it down it didn't take much pressure to get it to that 30 lb point. I just feel more comfortable going an extra few ftlbs. The way I feel is that when you use a torque wrench the when you hit that ftlb mark then when pressure is let off the wrench you will have a little flex back on the bolt head. And plus I don't feel that you will get an accurate torque since there is friction between the treads on the bolt and the block. I just want to make sure it seals good.

Are you sure your Torque wrench is Foot pounds and not Inch pounds

Joe

[Save Old Iron 1,563]

30 inch lbs - well that would be about what you could tighten the headbolts by hand using a nutdriver B)

[CochinsRus 0]

Yes it is foot lbs. i double checked my self because it feels odd.

[Save Old Iron 1,563]

and bear with me here

not Newton / Meters ?

because that would be about half the torque rating of ft lbs.

I screwed up on that one time with a new digital craftsman wrench.

[CochinsRus 0]

It was foot lbs. I got a second torque wrench which had been calibrated and I placed it at 30lbs and most of the bolts moved a little. So I will run the engine in the next few day and them torque again.