Rob94hawk

iTrader: (1)

My 1/2" Crapsman torque wrench broke last night so I used my backup 3/8". I only got 1 head on but I want to get my hands on a Snapon torque wrench.

What I did with the one head was, after going 15/25/45/75, I backed all the bolts up a bit and re torqed them. The angle did increase after I did this.

My question is, when I get my hands on a REAL torque wrench, should I just check the bolts by tightening them, or backoff and re tighten again? Note that I only have one head on so far and I used the ARP Ultra thread sealer.

Will this fatigue the ARP bolts?

camar0corey

iTrader: (22)

I've always used a 3/8" Craftsman torque wrench, I've done head gaskets on 3 LT1s, they never had any problems. Are there studies out there that show Craftsman torque wrenches are way off or something?

RamAir95TA

iTrader: (2)

Why did you back off the bolts and retorque them? Backing them off negates the purpose of torquing them in stages. Just make two passes per torque spec - that's all you need.

The bolts won't fatigue. They can be used over and over again.

SS RRR

iTrader: (2)

Never have.

I dunno. I've had the same Craftsman 1/2" and 3/8" drive torque wrenches for the last 11 years and they work perfectly, and as stated, ARP bolts will not fatigue. I'm using the same ones that I bought like 6 years and a-half-dozen-times-the-heads-have-been-off-the-block- ago.

Rob94hawk

iTrader: (1)

Don't remember where I read it but after you do the final torque, back it up a bit and re torque. When I did this the torque wrench did travel further before it clicked.

I'll have to find the article for the rationale behind the whole thing.

Rob94hawk

iTrader: (1)

This was a fairly pricey digitorx 1/2" wrench that I bought 9 years ago. Damn thing crapped out and leaked what looked like hydrolic fluid and now the head spins freely in both directions. I took it to Sears today and they wont even replace it so I'm **** out of luck.

SS RRR

iTrader: (2)

Yeah mine are mechanical. Isn't that kind of against their policy? I thought every Craftsman tool was guaranteed for life.

Rob94hawk

iTrader: (1)

I'm gonna go to Sears Hardware and see what they say.

SS RRR

iTrader: (2)

Make a scene. Go insane.

Lonnies Performance

iTrader: (16)

Here are a few things related to head bolt torque.

1. Retorquing is typically done to compensate for the head gasket taking a set, usually after running & heat cycling.

2. Typically it is best to retorque bolts when they are new. This actually smooths out the threads whch can result in a slight additional movement as you noted, due to less thread friction. Many bolt manufacturers recommend retorquing on new critical fasteners. I always do on my engine builds.

3. When you retorque, only loosen 1 bolt at a time & retorque it in 3 steps as recommended. Do not loosen all & retighten.

As for you retorquing the heads, it would not be a bad idea if this is a high HP application (forced induction or nitrous) Typically I never see any head gasket failures on normally aspirated vehicles, other than high mileage stock motors.

As an FYI, I only typically see the long head bolts change position during a retorque. The short ones do not seem to change as much.

BLK,97,T/A,M-6

I havent retorqued mine and they seem fine after 6500 miles. That doesnt mean that doing it isnt a bad idea, but I have been fine.

great421

iTrader: (1)

Actually (as an FYI), STOCK LT1 head bolts are Torque to Yield (T2Y) fasteners, meaning once the total torque is applied they will indeed stretch beyond their elastic limit, so once they've been 'torqued' they cannot loosened and then be used again.

Now, a set of ARP Stainless Steel head bolts, those can be reused and re-torqued, no problem.

JAKEJR

No they're not. Just another example of inaccurate information that gets passed around and simply won't die.

I wonder how this ever got started anyway. Someone posted it or said it and others just picked up on it and ran with it?

Jake

RamAir95TA

iTrader: (2)

Another person thinking stock bolts are TTY....ugh.

I was specifically talking about ARP bolts.

Lonnies Performance

iTrader: (16)

There is no such thing as a torque to yield bolt.... this is only the method for tightening any bolt. Once it reaches a certain stretch value it yields.

As for the LT1, the 92-95 states a specific torque value.

Some of the specs for the 96-97 manuals state 22ftlb plus 80deg on long & 67deg on short. This is torque to yield.....

If you have a 96 up car I would never reuse the bolts. Personally I also question reuse on the earlier cars, as I do not know the method for installation at the factory.....

This is where the myth or FACT came from.

97pontta

iTrader: (10)

Just to make sure I understand correctly, ARP head bolts can be reused. I have ARP head bolts from my original head swap and are in great shape and would like to use them on my current 355 build.

shbox

TTY bolts are for real (that is what they are called). They are just not used on the LT1. The method for tightening is called torque/angle. People get confused about the bolts because of the change in method stated by the manual (as you noted). The actual bolts did not change, though.

The torque/angle method is a more precise way of tightening a fastener that helps negate friction errors. A TTY bolt must always use the torque/angle method, but a normal bolt can use either (if both methods are supplied). The torque/angle method has been used in industrial applications for many years.

shbox

Yes, you can reuse them.

JAKEJR

Yes, ARPs' are reuseable naturally, of course, if they are undamaged. Although there are other manufacturers of excellent bolts - I recall using SPSs before ARPs hit the scene - but my opinion is that ARPs are the best fasteners made.

TTY bolts have been used for years on European cars, but more recently on American made cars. Those are the ones that should not be re-used. Like so many other thngs, though, where guys deviate from what's recommended, there are some who claim TTY bolts, too, can be reused, but I definitely wouldn't.

Jake

97pontta

iTrader: (10)

Ok, thanks guys. They are in great shape so that will save me some coin on the build.