Re-using head bolts? No problem!

[Toysrme]

1993 3vz-fe head bolts are nice.
Trust me in that they don't snap in half until 140-155 lb-ft.
I know, I did stress testing before I put my engine back together in a vice!

[white90dx]

Unless the factory service manual says you can reuse them, don't. They are probably stretch bolts. Just because they didn't break until the torque you stated doesn't mean they don't stretch/change before that time.

-Charlie

[tCshamgar]

I dont think that sticking the bolt in a vice is sufficient as a stress test. To really have an accurate stress test, you would have to take into consideration the temperature the bolts would operate under. Plus the stress you are putting on the bolt is on a different surface area rather than the threads alone.

I believe its best to go with manufacturer's reccomendations and change them per use. Not that you couldn't re-use them once. Its just not guaranteed to work.

[Deep]

Originally posted by white90dx
Unless the factory service manual says you can reuse them, don't. They are probably stretch bolts. Just because they didn't break until the torque you stated doesn't mean they don't stretch/change before that time.

-Charlie

Werd, they're designed to stretch a little when torqued down. Torquing them, removing them, then torquing them down again is asking for trouble.

[Toysrme]

They went through a die just fine. Considering 140lb-ft is 3X the 25lb-ft + 2 1/4 turns.
I happen to think it's a safe bet they're fine

[88 LE]

I would use new head bolts.

But hey its your engine, do whatever you want.

You might want to read this:

http://www.arp-bolts.com/pages/tech/fastener.html

[Tony the Tiger]

You can reuse headbolts, but to compare the price for a set of new head bolts vs the price for new headgaskets and time/labour, it's not worth reusing them.

It's the same deal with people reusing O-rings and gaskets. You can get away with it, but it's not worth the trouble to save a few bucks if anything does go wrong.

Not a smart choice, but good for saving a few bucks for snack and coffee.

[Toysrme]

New headbolts are another $50. Not worth it when the old ones are fine IMHO.

You can get a gasket set for the entire 3vz-fe on ebay for like $100

[alltrac165]

Make sure they are not torque to yield bolts. If they are, you will NOT get the same clamping force as the bolts delivered the first time. They are never supposed to be re-used. Standard head bolts can be reused a few times as long as they have not been overtorqued ever. If they have been overtorqued, then they have lost their elasticity (stretched past their ability to return to original size) and thus lost their clamping ability. Most performance builders use new bolts just to be safe. I have re-used stock bolts on about a dozen engines with no problems, and I know LOTS of people who have done the same so I know it can be done, but I wouldn't do it if I was building anything other than stocker. Testing breaking points in a vice won't test for elasticity, btw. As with anything, you must weigh cost against risk.
Just my opinion, ymmv...

[TcmaBoy]

I tried reusing a set of head bolts once on my 280Z. It was a junker I bought to get arround in after I wrecked my truck. I almoast got away with it. I tested for compression and it passed. The trouble was that one of the bolts wasn't holding quite tight enough and I ended up with a slight oil leak at the front of the block. I was broke and needed a ride until the insurance paid off. Unless you are that hard up, don't cheap out, just get new bolts.

[sleepr]

arp

[halforc]

the manual for the ae92 says nothing about buying new head bolts.

[Tony the Tiger]

Originally posted by Toysrme
New headbolts are another $50. Not worth it when the old ones are fine IMHO.

You can get a gasket set for the entire 3vz-fe on ebay for like $100

You cannot say that the headbolts are fine... Reusing them is always a risk.

Bolt stretch occurs in thousandths of an inch... It happens at the head of the bolt as well. The threads may look okay, but when it stretches further (or even snap), pop goes your headgasket Then you get into overheating issues, the risk of warping the head, etc... The risks outweighs the measly $50.

Like I said again, for $50, I am sure even your own time (labour) and upper gasket set is worth than that. It's not ideal to be reusing them. Same deal with rod bolts

[TekPhobia]

Originally posted by halforc
the manual for the ae92 says nothing about buying new head bolts.

Does it say something like, "Tighten in 3 passes to xxft-lbs, then turn an additional 90° followed by another 90°.." If so, then you've got TTY bolts which should be replaced after usage.

-Tim