Do you reuse head bolts?

This has become another engine rebuilding dilemma for me. I have searched many Chevy hot-rod/racing forums and the responses are almost 50/50 for/against reusing head bolts.

Here is the specific question for the poll.

If the heads in question are OEM Chevy 350 Vortec's and use TTY (torque to yield) bolts AND the motor is being rebuilt to stock/OEM performance standards...is the installation of new bolts really necessary?

The cheapest set I can find are $35. The "good" bolts (ARP) can run well over $100! I question the motives of those who manufacture and market the TTY bolts as just another way to profit from the ignorance or fear of unsuspecting home mechanics. BTW, I already know that the "industry" says I must use new bolts. However, my machinist says, "BS, clean and use the old ones." As does a number of Chevy wrench turners on their respective forums. Opinions and experiences from iboaters are appreciated.

Re: Do you reuse head bolts?

They are not TTY bolts. Mercruiser SM says to clean bolt and block threads, sealer on bolt threads just before running them in. Nothing about discarding. For vortec heads, there is angle torque spec, three pass procedure.

Re: Do you reuse head bolts?

If the heads in question are OEM Chevy 350 Vortec's and use TTY (torque to yield) bolts AND the motor is being rebuilt to stock/OEM performance standards...is the installation of new bolts really necessary?

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Ayuh,... As John said, they're Not....

Clean up what ya got, put perfect seal on the threads, 'n torque to spec with the angle meter...

Re: Do you reuse head bolts?

Silly Seville said:

forums and the responses are almost 50/50 for/against reusing head bolts..

Click to expand...

and now iboats is 50/50 too...

Re: Do you reuse head bolts?

Do you reuse head bolts?

Depends:
Check each existing bolt for elongation against OEM specs.
If the heads have been shaved and/or the block decked, ensure that no bolt bottoms-out prior to reaching its clamping load.

Re: Do you reuse head bolts?

Way too many people mistake angle torque as being for TTY bolt only. They are not.

None of the Chevy manuals, or Merc, Volvo, OMC or any others say that you need to replace them. Just because the hot rodders want to replace original head bolts to TTY bolts doesn't make it a huge deal on any marine engine that doesn't use TTY head bolts. It's just not necessary.

But nobody is going to change their (Never reuse head bolts they are TTY) minds about reality.

Re: Do you reuse head bolts?

180shabah said:

and now iboats is 50/50 too...

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No, iboats is 100% in favor of actually following the manufacturers recommendations. they are NOT TTY bolts and can be re-used if they aren't damaged.

Re: Do you reuse head bolts?

The poll is useless. If the person voting doesn't understand, then he is just giving a false opinion, not facts by any means.

Re: Do you reuse head bolts?

Don S said:

The poll is useless. If the person voting doesn't understand, then he is just giving a false opinion, not facts by any means.

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Ayuh,.... I think that by definition, a Poll is Opinion.....

Right,...

Wrong,...

Or otherwise....

If ya really wanta hold yer heads on,.... Use Studs, 'n Nuts....

Re: Do you reuse head bolts?

eehhh. The first head i ever did an rnr on was a foreign motor. There was even some question on that. So seeing that this was my first major motor work i opted for the new bolts. I think if i recall i didnt clean out the threads good enough and it failed about 25,000 miles later.(it was my car) Anyhow, i dont think the gm blocks require new bolts. My point was clean out the female threads part of your block with a thread chaser/cleaner then blow it out then do it again.

Re: Do you reuse head bolts?

It might have been the harbor freight torque wrench i used too.

Re: Do you reuse head bolts?

Have since gotten rid of all my HF tools.

Re: Do you reuse head bolts?

I reuse head bolts on sbc that is a stock rebuild. If it's getting worked over... then i will pop for the arp's. My Silverado in my sig got arp's when i put LS6 heads on her... I went for them because its Procharged. But that's just my thoughts and opinions. So you see, you can do as you like.

Re: Do you reuse head bolts?

either way is fine as long as the bolts are in good shape and they are not TTY. As you can see by the poll numbers it is a toss up on what people prefer to do.

Re: Do you reuse head bolts?

tpenfield said:

either way is fine as long as the bolts are in good shape and they are not TTY. As you can see by the poll numbers it is a toss up on what people prefer to do.

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The problem with this poll is that it is assuming TTY bolts when they are not.

Re: Do you reuse head bolts?

They aren't TTY. If you like they way they look, reuse them. If it's going to keep you up at night, spring for new. You can get the GM pieces for $30 or so (if memory serves) or get as spendy as you'd like if you go through the ARP product lines. If you do stud it, make sure you wouldn't have any clearance issues with removing a head with the engine installed at some point down the road.

See below for the auto equivalent of that vintage:

Cylinder Head Installation On
1996-98 GM 5.7L VIN R Engines

The AERA Technical Committee offers the following information on cylinder head installation for 1996-98 GM 5.7L VIN R engines. This information is somewhat different than previous engines. GM is now recommending a torque turn method of tightening the cylinder head for this engine. It does not however, use a torque-to-yield bolt to mount the cylinder heads.

The cylinder head mounting bolts may be reused if they are not damaged in the threads or show neck-down or stretch condition. The bolts should be thoroughly cleaned of sealer before inspection and installation. Cleaned bolts should have a coating of GM sealing compound Part #1052080 applied to the threaded area only. The use of an aftermarket equivalent sealing compound is also acceptable to use on threads.

Follow the steps listed below to correctly install head gaskets for this engine being careful not to get any seal on the head gasket mating surfaces or gasket.

1. Place the head gasket over dowels with the bead up.
2. Carefully guide the cylinder head into position over the dowel pins and gasket.
3. Coat threads of the head bolts with sealing compound and finger tighten all bolts.
4. Tighten all bolts in sequence shown below to 22 ft. lbs.
5. Tighten all bolts in sequence an additional turn in degrees, using J 36660 tool.

Short bolts (3,4,7,8,11,12,15,16) additional 55 degrees.
Medium Bolts (14,17) additional 65 degrees
Long Bolts (1,2,3,5,6,9,10,13) additional 75 degrees

The bolt numbers correspond to the "normal" Small Block torque sequence.

The AERA Technical Committee

Re: Do you reuse head bolts?

We have been putting sbc together for racing 25+ years, and use ARP bolts, and we reuse head bolts, and main bolts, we discard rod bolts, and install new ones. Stock motors can reuse stock bolts, I would put new rod bolts in though. My .0002

Re: Do you reuse head bolts?

90stingray said:

I reuse head bolts on sbc that is a stock rebuild. If it's getting worked over... then i will pop for the arp's.

Click to expand...

Stock or mild rebuild, reuse. 800+HP gets ARP bolts everywhere on our engines.

Re: Do you reuse head bolts?

Thank you everyone for your input! I asked the question with the understanding that the head bolts were TTY. I did not come to that conclusion on my own; the AutoZone guy AND Summit Racing sales rep told me they were during a visit/phone call. That lead me to ask the guy who machined and prepped my block the same question; and he said nonsense, they were NOT stretch bolts. Thus my confusion and cause for the original post. I have examined all the bolts and they look good. I also got a thread cleaning kit to use on them (block holes too.) If these are in fact reusable, what sealing product should I use on them? I have heard too many opinions to feel safe in making the right choice alone. Some suggestions were blue or red locktite, red or orange RTV silicon, Permatex # 2 or 3, Aviation form-a-gasket, and something made by Versa-Chem that is a copper colored, gooey mix in a can with a brush applicator. Another fellow told me to just dip them in engine oil. I did attempt a Gargle search on the GM sealant # given above, but cannot find its "aftermarket" equivalent. Also, one more thing...in case it matters...I am putting these '97 heads on an '87 block, and I have the original bolts that came from the old 882 heads that were on that '87 block. Should I just use them instead, or stick with the ones that I pulled out of the running '97 engine?

Edit: Bondo-O; which # or "formula" of Perfect Seal?

Re: Do you reuse head bolts?

Use whichever bolts you like, but I don't see what you'd gain by running the older bolts if all else is equal. Whatever you decide, the torque spec matches the bolt and if you're doing the torque-angle method use the bolts out of the '97.

Make sure the thread cleaning kit is in good shape so the threads aren't messed up in the process of cleaning. Mercruiser specs Quicksilver Perfect Seal, which is the same as the Permatex Aviation (#80017 for the 16 oz. bottle).

Finally, some guys end up having problems getting head bolts to seal if they enter water jackets, leading to water in places it shouldn't be and inducing panic. A good way to prevent this is to apply a bit of sealant to the relevant female threads in the block. This pushes a "plug" of sealant in front of the bolt as your tighten, rather than having much of the sealant being scraped off by the female threads as you snug everything down. I personally cut the end off a q-tip - I find the shaft works pretty well.