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Author Topic:   Head Bolts
ryan
Dirt Freak

Total posts: 432
posted May 04, 2003 09:32 PM
Head gaskets were leaking water so we checked the torque on the bolts before tearing it down. The bottom row of bolts were about 5lbs under give or take and the top ones were at most 20lbs over some were good but the majority were not. Anyone know why this would happen? Any suggestions to keep it from happening again? Thanks

sdhnc29
Dirt Freak

Total posts: 469
posted May 04, 2003 11:12 PM
Odds are your bolt holes have rust in them , and your not getting an accurate torque to start with . It's also not accurate to check the torque on the bolt when disassembling the engine , due to the fact that the actual breakaway torque is greater .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

rico 08
Dirt Freak

Total posts: 372
posted May 05, 2003 02:08 PM
You know it always seems as tho the bottom bolts don't hold the clamping force that the others do,i've always blamed the hot exhaust side of the head but who knows.

ryan
Dirt Freak

Total posts: 432
posted May 05, 2003 04:48 PM
Seems possible steve but would that cause the head gasket to leak. Seemed like when I took off the head it came off way to easy. There were tiny puddles on top of the pistons and most of the gasket was wet.When we take the heads off usually we have to give it some persuasion but just a slight yank did the trick. Any tips for better sealing of the gasket. I will clean up the holes no matter what they look like.
Thanks again

ryan
Dirt Freak

Total posts: 432
posted May 05, 2003 04:48 PM
p.s. I was using fel-pro gaskets
355 with bowtie heads

[This message has been edited by ryan (edited May 05, 2003).]

sdhnc29
Dirt Freak

Total posts: 469
posted May 05, 2003 10:58 PM
ryan ,

I would definitely run a tap through all of the head bolt hole's . A lot of times the very bottom thread's will be slam full of rust , sealer , and various other debris from year's of use . Another consideration would be if you used after market head bolt's . Most of the aftermarket bolt's are a little longer than stock . You will find sometimes , when running a tap through the bottom row of bolt holes , that in some of the holes there is actually some casting flash just below the last thread in the block . Any of these problems , along with not lubricating the thread's with sealer and the head of the bolt with oil , will give you a false torque reading . I'm thinking that you will be finding crap in the bolt hole's though .

As for better gasket sealing , I'd re-torque your heads after the engine has been run through a heat cycle . I know that the Fel-Pro is a "perma-torque" , but I guarantee that you'll get a little extra on them when you re-torque . Simply heat the engine up to 220-230 water temp , let it cool back down to room temp , and re-torque the heads . Be sure to back each bolt off 1/4 turn , and then come back up to your torque spec .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

ford5
Dirt Freak

Total posts: 299
posted May 06, 2003 06:52 AM
also a longer bolt will stay tight better than a shorter one, the torsional twist is what maintains the torque.

jnewman44
Dirt Full Roller

Total posts: 74
posted May 06, 2003 08:51 AM
Hi, Does a solid copper head gasket require re-torquing?

ryan
Dirt Freak

Total posts: 432
posted May 06, 2003 10:06 PM
Block was cleaned along with the other machine work before it was built. I do have aftermarket bolts. The holes look o.k. but I'll chase em' anyways. Thanks all

Eljojo
Dirt Freak

Total posts: 278
posted May 06, 2003 10:23 PM
Always chase them! If ya feel froggy chuck the tap up in your drill and you'll be done before you know it----be careful you start the tap correctly!

Eljojo
Dirt Freak

Total posts: 278
posted May 06, 2003 10:24 PM
The previous post was brought to you by the same guy who did not use sealer on the head bolts and started the "water in oil" thread....LOL

madmodshoe
Dirt Forum Racer

Total posts: 90
posted May 06, 2003 11:04 PM
dont forget your head bolt bearings!

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