Okay, I know I'm supposed to know what I'm doing, but the question of how tight to make the head bolts stumps me. Judging by their size, the thread pitch and the aluminum block, I'd say 75 to 90 ft. lbs. The manual sez 22 ft lbs. But then it says two 90 degree turns for used bolts. Now should I sneak up on 22 ft lbs with two 90degree "approaches"? Or should I tighten to 22 and then go to two more 90 degree turns?

A clue for me is that going from just seated bolts at no torque to 22 ft lbs takes only about 1/3 of a turn, so I don't know how they get 90 degree twice.

So I'm guessing it's the first scenario, but I'd like to hear from someone who has done at least a few S2000 motors to see what you think. And yes, I've read a bunch of the archives, even read the AEMS bulletin about head studs, on this issue, but have not been able to discover definitively straight answer.

I'm putting some serious work into this motor and I'd rather not have something this "simple" screw me up. Any help would be appreciated.

Thanks,

Jim

 

Jim,

Honda goes by stretch of the bolt and not torque reading. Go to 22 lbs then add the 90 degree turns. New and used bolts are different.

 

I have my head off and I am putting it back on soon. I have new oem head bolts and will be torquing them all in the proper sequence to 22ft lbs. Then going the 3 90degree steps in sequence as per the manual. If it is how honda specifies I assume it should work fine.

 

Jim

I have to use a breaker bar to get the last of the 3 90 degree turns (new bolts) in. So they are good and tight by the time you complete the documented Honda process. I think the breaker bar is 36" and 3/4 drive. It is huge.

 

you have your answer here...but let me tell you my story, just to share.

i misunderstood the manual like you almost did.

i torqued my bolts to 22 ft/lb and scratched my head at the 2 90 degree turns. i completed assembly of the head with the head bolts at 22 ft/lb and drove around for 1 week, even vtec'd a few time.

after a week of scratching my head, i finally asked around and knew what i had wondered all along, 22 ft/lb is not enough.

so instead of removing the head completely and installing a new head gasket, i merely removed the valve cover and cam lobes and used a needle torque wrench to guestimate the torque setting on the first bolt...the needle started to move at approximately 24 ft/lb, so i figure it didn't tighten much during the 1 week of driving.

i proceeded to add 2 90 degree turns with the needle torque wrench and after the 2 90 degree turns, it read 105 lb/ft.

i used a click-type torque wrench and torqued in sequence all the other head bolts to 105 ft/lb. the other bolts moved approximately 2 90 degree turns, but not exactly...most were a little less than 2 90 degree turns...like 1 90 degree, then a 60 degree, and then click.

i felt semi-comfortable about this and have been driving like this for about 1 year now, including 1 track event.

i've done compression test, at 200-210 range. leakdown was done last month at 6-7% leakage.

i feel find now about using 105 ft/lb and kind of deviating from the service manuals instructions...although i would never recommend this...