LathersR

Im in the midst of changing my head gaskets in my stock 96 formula a4. I was going to order the arp 134-3701 head bolt kit and the fel-pro 9966pt impala ss head gaskets. Is that a good way to go? Besides the head gaskets all I need are the intake and exhaust gaskets? I know Im going to have to have the heads checked and machined but Is there anything else I should possibly replace or going to need?

bw_hunter

You should also consider changing the seals on the crossover pipe which attaches to the back of both heads and runs forward next ro the intake manifold on the passenger side. I'd replace the TB gasket as well...you pretty much have to remove the TB to get the manifold back on and torqued correctly.

You'll get a lot of recommendations on what sealers to use but here is the minimum....Teflon thread sealant on all the head bolts, Teflon sealant on all the intake manifold bolts, lead free antiseize on the exaust manifold bolts. GREY RTV sealer on the front and back of the block where the intake manifold seats against the block.

Good luck....

97Z28Muscle

I used Fel-pro head gaskets and intake manifold gaskets. My engine shop that I used for my rebuild recommended only using permatex ultra black RTV sealer for the front and rear of the intake manifold. I also used the ARP head bolts, and they must be replaced because they are torque-to-yield bolts. What this means is that the bolts can only be used one time, because they are meant to stretch as you tighten them. The ARP bolts are about $90 or so, but worth every penny. Like bw hunter said:make sure you put thread sealer on all of the head bolts, because some of the threads enter the water jacket. If you don't do this you may have yourself a leak. The rubber gaskets/seals on the rear of each head, that connect the rear of the heads together(water pipe), whatever you want to call it:The washers from GM are about $8 each, and they are they only place to buy them. Make sure you clean the pipe well, blow it out with air and make sure it's not blocked. You should be good to go if you just take your time.

shoebox

The bolts are not actually TTY, but it is still a good idea to replace them. The steam pipe washers can be had at most auto parts stores, but are usually called oil or a/c seals and much cheaper than the GM part.

97Z28Muscle

The LT1 rebuild manual that I purchased specifically states that the bolts are TTY. I'm not an expert, but that's what I read, and that's why I bought the ARP head bolts. When it comes to that steam pipe...being located where it is, and very hard to reach, I just bought the correct part from GM. I didn't want to take the chance on some other part that may or may not be made for that application.

MtrSkllz

because they are torque plus angle most assume they are tty, but they are actually stretch something or other, and they can be reused. but i wouldnt. you seem like you have done your homework, and you are making the right choices
arp bolts and impala gaskets are what i used, and would always recommend.

PWR SHFT

ALL bolts stretch when tightened.

TTY bolts when torqued, are stretched beyond the elastic state and into the plastic state of the metal of the bolt. Once you hit the plastic state, the metal will not return to its original state when loosend which is why you cannot reuse TTY bolts. The engineers on the site can probably correct this or state it better, but this is my understanding.

Regardless, ALL bolts stretch when tightened.

97Z28Muscle

That's my understanding, and these head bolts ARE torque-to-yield. The method for installing them is called torque plus angle. Meaning of this: Torque each bolt in sequence, then go back and angle tighten them to a certain degree. Some are 67 degrees, others are more. You can purchase an angle gauge or do like I did and use the "common sense" method. If 90 degrees is 1/4 turn, 67 degrees would be about 3/4 of that. Very easy to do, but that's what GM recommends.

shoebox

LT1 head bolts are not TTY, no matter what you read elsewhere. The factory manual does not indicate they are TTY and they are the same bolts used in previous LT1 years where the torque/angle method of tightening was not used. TTY bolts in the LT1 is a myth that just won't die.

BTW, I would not do the T/A method without a meter. It is a precise method. "Common sense" is not accurate enough.

97Z28Muscle

I tried to buy an angle meter without success, nobody sells them. The LT1 manual specific to 92-97 LT1 engines specifically states that these bolts are not to be replaced, and that they are TTY. Using the "common sense" method worked well for me, and have not had one problem. The T+A tightening method was only introduced in the early 90's, according to my engine machine shop. They tell me before this, they always used torque method only, in sequence. Whatever method you choose to use, just make sure you go in sequence and tighten everything down using equal pressure, you won't have a problem.

MtrSkllz

you dont need no meter, just put a paint mark on it and follow that

shoebox

Huh? Isn't that contradictory?

Believe what you want. They are not TTY. The real (factory) manual says nothing about them being TTY. The GM parts book listings pretty much confirm this. Plus, TTY bolts have a different look from normal bolts. As I said (and partly because of incorrect info from printed and other sources) the myth won't die.

Nobody sells an angle meter? I wonder how I bought one?

shoebox

You're pretty awesome if you can eyball 67 or 80 degrees with a paint mark. Do you eyeball bearing clearances, too?

bw_hunter

They are very hard to find...the search took .008 seconds...LOL

http://www.toolprice.com/product/8798C

bw_hunter

And before lights we had candles. Before cars were horses...all a lot of 'so what'.

What we seem to forget is that torquing a bolt is a way of preloading it so it will stay installed and hold the parts together....preloading applies an adequate amount of stretch to the bolt. With through bolts, like those on a connecting rod you can simply measure the before and after length and know you've done it. It appears that engineers have found that a particular angle of twist after a specific torque gives them what they want. It wouldn't have replaced the older methods if it wasn't sound. By the way...the early 90's was nearly 20 years ago, we can embrace this by now, can't we?