Should i use new head bolts?

I'm in the process of rebuilding my engine. It's a mildly built '65 327. Should i use new head bolts or are the old ones okay?

 

Get new ones! Head bolts "stretch" when you torque them and shouldn't be re-used.

 

I'd re use them if they are not rusted too bad at the threads.

Head bolts in modern engines stretch and should not be re used. Head bolts from the 60s are not the same...they are designed to be used over and over. They do not get very close to "yield strength" with proper torque.

 

My Machinist said never reuse head bolts Never ever!! Your call

 

I'm with Squirrel on this one... If that motor had never been rebult before and they're not rusty including the hex part, I'd re-use them without batting an eyelash..

 

order new ones, that come from china, and dont meet specs anyway, and are junk, use the old ones

 

For 60$, why take a chance? It's a no brainer. ARP

 

Bottom end for sure, tops will be fine.

 

It ain"t like you are building a newer piece of **** aluminum head 4-banger,reuse the old ones.The new bolts are not as good as the original.

 

I agree and never had a failure yet.

 

Use the old ones if in good shape ; if not in good shape buy some ARP bolts

 

The only time I use new head bolts in when I don't have any to begin with, or the parts book calls for them.

 

SBC reuse them only the newer engines need to be replaced. Been doing sbc since 1970 NEVER had a problem reusing any of the bollts

 

same here...my little '65 283 is going back together with the bolts it was born with...been doing this for decades...no problem.

 

The bolts look good, no rust at all. I know the engine's been apart at least once because it's .30 over and has early model 350 heads.

It's a mildly built '65 327 that's bored .60 over, align bored, decked, reconditioned rods with new bolts, .194 (76cc) 350 heads, Comp Cams 268H cam, roller tip rockers, gear drive, Edelbrock Performer intake, 600 cfm Performer carb and an HEI. I was just thinking since ARP has them for about $65 they might be cheap insurance.

 

If you want to spend the money, go ahead. Probably won't avert any trouble, but it might make you feel better about the engine.

 

back when i was into truck pulling we pulled the heads on our SBC lots, sometimes once a week, same bolts it came from the factory with, i bet dam never 50 times those heads were pulled, no trouble, no machine shop ever suggested replaceing bolt and they had bolts to sell.

 

Maybe i'll just put that $65 towards buying a new torque wrench since my seems to have ran away.

 

hey jim, i still see primer??

 

It's not a BAD idea to get new ones, as long as you get good quality ones (like ARP)

But honestly, unless you're getting up to really high compression, or adding a blower, it's money you don't need to spend.

And don't buy a Craftsman torque wrench! Mine broke, and when I sent my wife to return it, they gave her a bunch of BS about the warranty not aqpplying to torque wrenches. I went back and got loud enough for it to apply again

 

I think most machinists today are only familiar with modern engines that use torque-to-yield bolts, which are single use. As noted, any motor from the seventies and before used head and main cap bolts that were nowhere near yield strength when torqued to factory specs.

Now, I'm sure we'll get lots of posts from people who snapped a head bolt when torquing, but unless the bolts have been overtorqued previously, there's no need to replace them. Heck, if you're worried about the bolts, the material allowables of the block that they screw into and the head that you're compressing are significantly lower than the allowables of the bolt. Why are you all worried about the bolts and not the underlying metal?

 

I re-used head, rod, and main bolts unless there is obvious damaged. I magnaflux them, but in over 50 years have never found one to be cracked. Check the diameter of the shank. If they have been stretched from overtouque they will be 'necked'. Clean the threads on a wire wheel and run a tap into the threads in the block to clean them out.

 

Always replace head bolts during the rework, (cheap insurance)

 

If the bolts are still in good shape and hold torque then I'd reuse them without worry.

These aren't the newer style torque-to-yield bolts that require replacement after one use.

 

If you find a torque wrench for 65$, don't use it! Good quality torque wrenches go for about 200$ around here.

 

The best, most reliable, foolproof, and least costly, is a bending beam torque wrench.

 

And most of all...the least accurate

 

That statement is without merit.

All other torque wrenches (clicker, internal ball/seat deflection, hidden bending beam, and otherwise, are calibrated against, guess what? A flex beam.

The clicker types are most likely to shift without notice and give inaccurate readings. In Air Force shops, FBO operations, and the Learjet manufacturing facility that I worked in over a period of thirty-nine years, all torque wrenches had to be calibrated on a fixed schedule. The labratories that calibrated them rarely found a any of our flexbeam/bending beam wrenches to be out of tolerances. When they were, adjusting the dial was the only thing that was necessary, because the force to bend the beam just don't change.
Just so you know.

 

It's likely more accurate than most any of the click-type torque wrenches out their in our shops. When did you last have your non-beam torque wrench calibrated? If recently, then it will be accurate for a while, but if it's been a while, I'd vote for the beam type being more accurate.

 

The 'clicker' types are the worst.
They shift like the sands in the Sahara............ I cleaned out my tool box a few years ago when the price of s**** was going up. Out went everything but the beams.