Head bolt torque
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Seasoned HDF Member
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From: Globe AZ
Head bolt torque
OK. I get to go down the broken exhaust stud road again, but at least this time I have the tools to do it myself. Backstory is about a year ago, I broke the lower exhaust stud on the front head, and sent it into the shop to have repaired.... no biggie, but about a week later the head gasket was leaking, necessitating being redone at shops expense. I do not know what head gasket they used at the time, but they torqued to FACTORY SPECS as per service manual the first time. Second time around they torqued using recommendation from a local engine builder, which was torque to a value, but again, I dont know what head gasket they used.
I will be using a factory HARLEY head gasket, but would like to get the consensus on what procedure to use when torquing the head down. With a factory gasket should I refer to service manual (value, value, angle?) or just do a set value? If a set value, what would be recommended for final torque, again using factory gaskets. I know some aftermarket gaskets like a different procedure, which is why Im asking.
Engine is a 2000 TC 88, bone stock, will be using the original head on original cylinder. Not going deeper into this thing than I need, its got 103k miles on it and doesnt warrant a big bore kit or any other extravagances at this time.
I will be using a factory HARLEY head gasket, but would like to get the consensus on what procedure to use when torquing the head down. With a factory gasket should I refer to service manual (value, value, angle?) or just do a set value? If a set value, what would be recommended for final torque, again using factory gaskets. I know some aftermarket gaskets like a different procedure, which is why Im asking.
Engine is a 2000 TC 88, bone stock, will be using the original head on original cylinder. Not going deeper into this thing than I need, its got 103k miles on it and doesnt warrant a big bore kit or any other extravagances at this time.
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From: Poolville
I would not use a OEM gasket.. Get a Cometic MLS gasket and torque to their specs.. Save yourself future headaches. If this is the second leaking head gasket, while you have the heads off I would bring them to a local machine shop to have the surfaces checked for any warpage and maybe skim them.. @ 103K you might even need a valve job at this point...
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Seasoned HDF Member
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From: Globe AZ
the head gasket is NOT currently leaking, but I need the head off to remove the broken section of exhaust stud. Damn thing is in a direct line to the frame tube. Ill be checking the surfaces when I get the head off, along with the valves. Worst case, the head is ****ed, and I replace both with a set of low(er) mileage take offs (not gonna do $$$ heads on a bottom end thats gettin tired)
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Joined: Feb 2018
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From: England
You shouldn't need to replace the head unless there is huge warping in the mating surface. One sheet of plate glass (glass being perfectly flat) some fine valve grinding paste and some engineers blue will sort out most mating surface problems. Spread fine grinding paste all over the face of the glass, put a light coat of engineers blue on the head mating surface, put head on glass and figure of 8 it for a minute or so. Any low spots will still show blue. Wipe glass clean and repeat as necessary until all the mating surface shows clean after the first minute or less.
I have lost count of how many engines I built using OE head gaskets - and these engines were tortured on the dyno and the street. Here is the trick we used and still use today. Follow the service manual for the initial two torques 120-144 lb in and 15-17 lb ft. Then following tightening sequence tighten to 35 foot pounds.
After tightening to 35 foot pounds, crack them loose (not sloopy loose, just loose enough to perform the 120-144 and the 15-17 THEN do the 90 degree turn per the manual.
Basically, do the first two steps, tighten to 35 lb ft, loosen and perform entire factory tightening sequence.
You will find that the 90 degree is really in the lowto mid 40 ish area and the 35 pre crushes the gaskets nicely. I have NEVER had an OE head gasket blow on any of the engines I built for SE Dyno class at HD or any of the street engines in all the years I built them.
After tightening to 35 foot pounds, crack them loose (not sloopy loose, just loose enough to perform the 120-144 and the 15-17 THEN do the 90 degree turn per the manual.
Basically, do the first two steps, tighten to 35 lb ft, loosen and perform entire factory tightening sequence.
You will find that the 90 degree is really in the lowto mid 40 ish area and the 35 pre crushes the gaskets nicely. I have NEVER had an OE head gasket blow on any of the engines I built for SE Dyno class at HD or any of the street engines in all the years I built them.
Last edited by Ed Ramberger; Jul 15, 2019 at 05:17 PM.
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Seasoned HDF Member
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From: Globe AZ
I have lost count of how many engines I built using OE head gaskets - and these engines were tortured on the dyno and the street. Here is the trick we used and still use today. Follow the service manual for the initial two torques 120-144 lb in and 15-17 lb ft. Then following tightening sequence tighten to 35 foot pounds.
After tightening to 35 foot pounds, crack them loose (not sloopy loose, just loose enough to perform the 120-144 and the 15-17 THEN do the 90 degree turn per the manual.
Basically, do the first two steps, tighten to 35 lb ft, loosen and perform entire factory tightening sequence.
You will find that the 90 degree is really in the lowto mid 40 ish area and the 35 pre crushes the gaskets nicely. I have NEVER had an OE head gasket blow on any of the engines I built for SE Dyno class at HD or any of the street engines in all the years I built them.
After tightening to 35 foot pounds, crack them loose (not sloopy loose, just loose enough to perform the 120-144 and the 15-17 THEN do the 90 degree turn per the manual.
Basically, do the first two steps, tighten to 35 lb ft, loosen and perform entire factory tightening sequence.
You will find that the 90 degree is really in the lowto mid 40 ish area and the 35 pre crushes the gaskets nicely. I have NEVER had an OE head gasket blow on any of the engines I built for SE Dyno class at HD or any of the street engines in all the years I built them.
While I have nothing against aftermarket gaskets normally, I had already purchased the stockers prior to posting (plus, they were damn cheap). This is a bone stock motor, not a fire breathing custom, and since the rear head has never been off, I dont want an issue (real or percieved) that there is a difference in spec between the two cylinders. With a myriad of thicknesses available aftermarket, and not knowing the thickness of a stocker, I went with a stocker
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