It was bound to happen. [I]Headgasket[/I]

[nismoplsr]

Well after running 18psi for a little over a year and 22psi for almost a year on the GT2860 the gasket finally gave way.

This was an OEM Nissan gasket with no copper gasket spray, and re-used "torque-to-yield" Nissan headbolts. Pretty impressive, i think.







Soon to come....TRUST 1.2mm head gasketARP head studs

[Fenvy]

hey... consider getting 1.5mm... I wish I had

[nismoplsr]

hey... consider getting 1.5mm... I wish I had

Why would I want to mess with the fluid and combustion dynamics in the combustion chamber?

[float_6969]

Changing compression via a thicker HG isn't the right way to do it. Unless you're compensating for milled block and head surfaces, there is no need for a thicker HG on this motor.

[Fenvy]

what is the right way then? block work? such as oversized piston, bored block.... etc?

[r34 gtr]

that head looks really clean man. one thing about the metal hg though is that you know its not going to blow out on you. something more important will instead! good luck on getting her back in, although you seem like a man who doesnt need luck.

[nismoplsr]

that head looks really clean man. one thing about the metal hg though is that you know its not going to blow out on you. something more important will instead! good luck on getting her back in, although you seem like a man who doesnt need luck.

That is sort of true, and people love saying that but...

People that say that tend to use the head gasket as a "fuse" when bad tuning is an issue. If you are blowing head gaskets due to detonation of course you would want the headgasket to blow at the lower levels of this than having the much stronger parts blow when the det. pressures get even greater.

However, in my case it was just the fact of weakened re-used head bolts, that eventually after years of high boost levels/combustion pressures stretched and weakened further. There were no signs of det. or lean conditions. I had not messed with the tuning either, so it was the same for almost a year, if bad tuning was the culprit i suspect it would have blown way earlier in my almost daily floggings.

This is just the fact that Nissan headbolts are just not up to the conditions of uprated power levels. The rest of the "more important" parts i believe are plenty strong enough to handle ,just as they have the past 2 years, what im going to throw at them.

I think the main factor isnt even so much the gasket as it is the bolts. I most likely would be fine with just using another OEM gasket but with ARP studs which have a much higher yeild strength, and intern higher fatigue strength. They should never have problems during normal stresses, obviously det. or pre-ignition may reach the critical strengths.

I am going to go with the metal gasket simply for the fact that i will be able to re-use it over and over.

[r34 gtr]

word. i have re-used mine 3 times and it just seems to seal better every time! i wasnt trying to bring the tuning of your car under scrutiny, i was just saying. i can see your car is running like a champ by looking at the head pictures. its almost clean enough to eat off of! that haltech should have your fuel and ignition on lock. good luck getting her back together mang!

[nismoplsr]

I didnt take it as you scrutinizing my tuning.

I just wanted to explain some things.I hear people saying "id rather replace a $50 head gasket than $800 pistons" or similar all the time. Then i always think to myself, how about you get your tune under control and you wont have to keep replacing your head gasket or your pistons.

Thanks for wishing me good luck!

I really need money more than luck though. Haha. I still have alot of work to do to the new chassis before i even think about putting an engine in.

[Woods Crasher]

So you were running 18 psi on a stock engine and head gasket with "compromised" head studs for over a year without trouble? I've been worrying about running 14 pounds on a stock bottom end with a s14 t28. I guess I should be ok as long as it's not too much my injectors and maf right?

[r34 gtr]

and the tune is good. remember this man has a stand alone.

[float_6969]

I've been running high compression and a T28 for a year w/o any problems on the stock HG w/ARP head studs.

I do have an oil leak though, but I think it's due to the cheap HG I'm using that came with the engine kit. I've got a nice felpro waiting to go in.

[Woods Crasher]

and the tune is good. remember this man has a stand alone.

Ah. That explains a lot then. Proper tuning for the win.

[dash]

does the FSM say ca18 head bolts are "torque to yield" ?

Water piping looks like fwd. Street car.. how do you manage with tracton @18-22psi ?

[float_6969]

There is a bit of a debate regarding the "torque to yield" bolts. No where in the FSM does it state that they are are, and I would think that if they needed replaced when you rebuild the motor, it would state that somewhere.

I THINK it came from some one reading the tightening procedure and assuming that the need for an angle wrench meant that they were torque to yeild.

I'm pretty sure he's got a Pulsar, so yes, this would be FWD. And that little sub-2400lb. car with a T28 @ 18psi must be insane!

[r34 gtr]

i dont think they are torque to yield, having dealt with some head bolts of that kind recently. however, i dont think its a good idea to reuse them more than once, as they are going to stretch at least some amount. i think it depends on how old they are (mileage) and stuff. basically if the engine has some miles, i would chuck them, and if you have re-used them once before. just my $.02

my s13 is fast as crap at 18psi, i cant imagine that pulsar. its gotta be sick! ...and i thought your oil leak was because the head wasnt level. mine does the same deal and thats the problem. havnt we gone over this? haha.

[float_6969]

I KNOW the head and block were straight as I watched them re-surface both of them. The motor has NEVER seen more than 190°F so I know it's not warped. It's got ARP hardware, so I know it's clamped down well, and since it's leaked from day 1, my only conclusion is that the gasket sucks. As I said before, it was a cheapie brand HG that came with the engine kit I bought.

[boost_boy]

Finaly, huh! It's race season, so it's time to fix that problem and get the car on a track. For you guys wondering about the stock CA18DET headbolts, the aftermarket stock replacements last longer and can be used more than the factory installed units.

Dee

[r34 gtr]

damn! well, at least i know mine is the head not being flat. my HG is too awesome to leak.