Need your opinions on doing headgaskets and other things.

[turbov6joe]

I am looking for opinions, be they pro or con, from those that have changed both headgaskets while the motor is still in the engine bay of their TTA.

Tonight I went out to the trailer to finish waxing my car and while the hood was up, I noticed that the radiator overflow was well below where it always is. I then inspected the radiator and found it pretty low as well; visable, but low none the less. I checked the oil and found no tell tale signs of a "milk shake", and the engine is idling glass smooth at 16"-17" of vacume like it always does with the 212-212 cam. It's running like a top and isn't giving me the typical "blown headgasket" signs I became so familiar with in the GN.....kinda got me stumped. Two weeks ago at the track the car ran great with little to no KR! However, I seem to recall over the last few months making a mental note that the car was running a little hotter than it typically does, this even when the ambient temps are rather low??? To the best of my knowledge the coolant has not been flushed in a while, and the water pump doesn't seem to be leaking, nor the radiator or hoses. Any other ideas out there? BTW, do the TTA's require any special headgaskets....what about headbolts/headstuds? I hate to break the original seal of the motor, but would rather do it now when it will be fairly inexpensive, rather than after the gasket really blows and takes out bearings and the turbo Any opinions/help will be greatly appreciated! If this was my GN I would have them changed by now, but the TTA is still kinda new to me as far as the different heads are concerned. TIA

 

[1badTTA]

Do a compression and leakdown test, that will tell you if you really are leaking coolant into the cylinders and which one. If you are then go ahead and order up the parts. You will need 2 headgaskets and an intake gasket, and headbolts, thats it. The trick to doing it in the car with the least amount of work is to leave the intake in place and everything hooked up to it, you will be able to lift it enough to replace the intake gasket. As far as wiping bearings when a gasket blows, drain and flush your coolant now and use distilled water and a lube, but not antifreeze as it will hurt the bearings much quicker.

Also, use a pressure tester on the radiator to see where it really is leaking, it is quite possible it isn't the headgaskets. HTH

 

[TTA850]

TTA headgaskets are the same as a GN,I like the Fel Pro 9441PT.But the head bolts are different,I belive Johns Performance has them - not sure who else.

Steve

 

[trading t/a]

These mtors in my experience blow into the intake valley rather than than out. As mentioned I would do a compression check and leakdown. #3 and #6 seem to be the culprits usually.


If the gasket has blown into the valley, it will pressurize it. If you take off the breather and white smoke comes pouring out it is a good sign of poor compression either from blowby from the rings pressurizing the crankcase or through the intake valley. Either way the tests will help you determine that.

As far as doing the job, it isn't that bad. John sells the arp headbolts(there is no kit, he puts a kit together), make sure the deck is ultra clean(use brake cleaner on the surface),use some thread sealer and if you like some loctite and crank them down evenly in sequence to their specs. Then heat cycle the engine(no boosting for a few miles then retourqe the bolts again. It's the only way to rteally get em to seal correctly.

Good luck

 

[turbov6joe]

I think I've blown them out more frequently than into the intake valley...only 1 time into the valley that I can remember. Seems if it's a BAD blow they go out, for some reason.

As far as re-torquing them is concerned, would it be beneficial for me to buy a 3/8" torque wrench with a pivoting head to make things easier? I seem to recall the GN's were a bitch to get a 1/2" torque wrench on when the engine was in the bay without using a bunch of extensions and a swival joint. If I use the RJC steel HG's they will require me to re-torque no matter what, and that might be a problem to do correctly if I can't get the wrench on every one of the bolts properly.

I'm praying that the leak is something stupid like a leaky heater core or something along those lines....prolly won't be, Mr. Murphey hangs out in my garage!

 

[1badTTA]

I haven't had any problems getting a 1/2" torque wrench on the bolts with a simple 3 piece extension set (1-1/2", 3", 6") It is nearly impossible to retorque after the headers are installed as they cover 3 bolt heads on each side.

As far as blowing in vs out, I have only had 1 go out (#3) and too many go in. Even had one (#6) go back through the water jacket.

I appreciate you letting Mr Murphy hang out in your garage, it keeps him out of my tool box (he likes to arrange things in there) and garage (he likes the fridge too).

 

[Russ Merritt]

Pressurize the radiator first. That will tell you where it's going.

 

[turbov6joe]

Russ,
Pressurizing the radiator will only tell me where it's going not including the heads right?

1badtta,
If I have to do the re-torque business, I'll prolly heat cycle the motor with ear plugs on and the headers off, that will save me a ton of time and heartache of having to muck with R&R the headers multiple times.....loud but effective!

I had a catastrophic headgasket failure one time when dumbass (me) forgot to put the vacume line back on the regulator after a FP adjustment and a 25 psi pass......BOOOOOMM.....4 of 6 gone and two billet maincaps wasted; all in 1 pass!

 

[1badTTA]

Actually pressurizing the radiator will tell you where it is going period. If it doesn't leak very fast you may need to keep it pressurized overnight to see where it is going.

Funny thing is that I just had the same problem with low coolant and high temps, I filled the rad and haven't had any more problems. It is still full and I am not worrying about it. It probably just had an air pocket in the heater core or something stupid like that. If it really is something major, it will show itself soon enough.

Also, after 3 different milkshake headgaskets I have 35psi oil pressure at idle in gear hot running 10W30. I cleaned the pickup but never had any bearing problems. HTH

 

[tta583]

Originally posted by turbov6joe
Russ,
If I have to do the re-torque business, I'll prolly heat cycle the motor with ear plugs on and the headers off, that will save me a ton of time and heartache of having to muck with R&R the headers multiple times.....loud but effective!

I don't think you can do that. My understanding has been that you have to have something to carry away the gases to get the heat away from the head. To much heat and things start to funny with the exhaust valves etc..

May be wrong, but worth the mention.

Brent

 

[trading t/a]

There are two ways to do it. One would be to tourqe and asemble the entire pkg. heat cycle it get some run time. On very low boost numbers put some pressure in there. Then take off everything and retourqe them. Only beneficial way of sealing these motors once the factory seal is broken.


You could prolly get away with laying the headers on there without the y-pipe and let the engine heat cycle a few times(much easier to rip apart. Ive done them and found that the uppers seem to get more loose than the lowers(can't say why, but that was the case the last two times i did it). For piece of mind after you are done with the retourqing and are comfortable boosting I would pull the VC's and tourqe the uppers yet again. Although mine blew into the valley not out.

On a side note I retourqed the TTY's down to about 90ft/lb. (Max the wrench read & all I was comfortable going to). I was boosting well into the mid twenties without a problem. However since the gasket didn't lift there had to be another relief valve and in this case it looks like it's the number 3 cylinder. or depends on how you look at it.

 

[turbov6joe]

1badtta,
I've heard that story before and have had the same thing happen with another car I had...so I'm keeping my fingers crossed here and we'll see what happens in the spring. In the interim I'm still going to do the leak down and compression checks to see what the status of the motor is and go from there. I'm planning on heading to my buddy's dyno this winter while he's slow and see what the power level is. I think while making a pull there should be tell tale signs taking place if a gasket is leaking....IE: breathers puking steam, bubbles in the overflow etc. If nothing else and the power is down from where I know it should be, that should point me in the direction of a problem or two. Thanks for the info!

 

[Race Jace]

Originally posted by turbov6joe
I think I've blown them out more frequently than into the intake valley...only 1 time into the valley that I can remember. Seems if it's a BAD blow they go out, for some reason.

As far as re-torquing them is concerned, would it be beneficial for me to buy a 3/8" torque wrench with a pivoting head to make things easier? I seem to recall the GN's were a bitch to get a 1/2" torque wrench on when the engine was in the bay without using a bunch of extensions and a swival joint. If I use the RJC steel HG's they will require me to re-torque no matter what, and that might be a problem to do correctly if I can't get the wrench on every one of the bolts properly.

It is not the gaskets that determine whether or not you need to retorque it is the head bolts. Stock TTY head bolts do not require a retorque because of their design, all other bolts do. Let me explain why they recommend retorqueing head bolts. When installing the heads you torque everything down at room temperature. By doing so you actually crush the gaskets. During normal engine operation the engine heats up. Thermal expansion occurs in the head and actually crushes the gaskets even more. Then when the motor cools the head bolts do not have the same clamping force as when initially torqued even though they have not moved or backed off. This is not as noticeable with iron heads as it is with aluminum as the thermal expansion rate for aluminum is much higher yielding more crush on the gasket during the thermal cycles.

hope this helps

 

[1badTTA]

Clears alot up here.

Would also explain why it is more important to retorque the 4 top bolts than the lower bolts due to longer bolts and more material to expand.

Thanks Jason.

 

[turbov6joe]

RJ,
Thanks for the insight. It would almost be easier and less time consuming to use a set of TTY headbolts and call it done. I've come to the conclusion that they can't be half bad as there are a multitude of HIGH mile motors out there running 25 psi on a regular basis. On my GN I tried about every bold/stud available and found that no one bolt/stud really helped control head lifting any better....kinda the price we pay for using a production block and producing entirely way too much power. That comment leads itself to say something about the original engineering that GM put into the production LC2 motors to begin with.

 

[Race Jace]

The aftermarket bolts/studs do offer more clamping force than the stock fastners. I think that the reason we have such good luck with the stock bolts is that usually the heads are not ported. Remember boost is what is not getting in the cylinder and although it is related to cylinder pressure it is only half of the equation. In other words in most cases unported heads are so restrictive that no matter how much boost we throw at them the heads don't lift.

on the top head bolts, yes the head does grow more due to more head thickness but they say real reason is, if a bolt stretches a certain amount under load the longer the bolt the more it will stretch.

hope this helps