ok, i put arp head studs on, and i did alot of searchin previous to install, i saw that torque amount was inconsistant but didnt mater. ie u can put 80 ft lbs or 70 ftlb, just be consistant, i went with 80 ftlb,since im boosted and thats what most did. but, i couldnt find anywhere that said if i should do them all to 80 or just the middle 6 and do the 4 end ones oem torque..i did follow the squence tho, thats for sure, but am i hosed no b/c i torques them all to 80? i folled sequens and did it, 20, 40 , 60 and then 80x3

You're fine. The sequence is important. The three step torque sequence is important. The end torque is the goal, and you said 80 ft/lbs. That's important. I wouldn't try to make 350wHP on it, but you're fine anyway.

Do it once. Do it right. If it fails from here on out, it's because you did something else wrong, not your head stud torque.

kool, wait why cant i try for that hp goal?

Originally posted by streetlightning
kool, wait why cant i try for that hp goal?

Not sure where Dino was coming from, but I can't think of reason why the motor won't take 350+ HP with the ARPs torqued to 80 ft lbs.

You should be just fine.

yah thats why i got concerned.. my bottom end is built, hence the use of the arp's..

Originally posted by streetlightning
yah thats why i got concerned.. my bottom end is built, hence the use of the arp's..

Go ahead and boost the shit out of it. I boosted 20-30 PSI on a Super 20G for a couple years with ARPs torqued to 80 and an MLS head gasket

^^^ What Doug said.

Same thing in my case also, although I went from a S16 to an SC61.
You will be fine with 80ftlbs.


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Santiago
boosted 420a...(2.2l v8 eater)
02 WRX
95 T/A 383ci
03 Harley XL 92ci w/ NOS

I went with the stock torque specs and never had a problem with blowing a head gasket...

Just blew my head-gasket 25 psi cometic head-gasket arp head studs. So i don't know it was all installed correctly i guess ill take it apart and find out what the problem was. Has anyone else had problems with cometic head-gaskets? Thanks.

im pretty sure thats ur prob, cometic sux. ive read that and seen that numerous times, use search button and ull see , its used but the best is the mopar MLS..

The factory head gasket has proven over time to be the best option. The Cometic brand works well in various applications, but there had been issues in the past with the 420a version.



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Santiago
boosted 420a...(2.2l v8 eater)
02 WRX
95 T/A 383ci
03 Harley XL 92ci w/ NOS

I can guarantee you that any issues from the Cometic gaskets are caused from improper installation. Great care must be taken during installation to make sure the inner rings are perfectly aligned. Also, you need to put a 50-60RA polish on the mating surfaces.

We use Cometic gaskets exclusively on 420A and 4g63 engines... I'm talking 25-35 PSI on GT30R, GT35R and GT40R turbochargers. Cometic is the only gasket I use.

Yea I did surface the block and head before installing the head-gasket and I am 100% sure that it was installed properly. I know cometic is a great brand I have used them before with no problems; however, until I take it apart I can only guess at what went wrong. I do know that it did blow into a coolant passage because there is air coming out of the overflow tank and the tank overflows when I really get on the throttle. Thanks for the information though.

Originally posted by dougie2
I can guarantee you that any issues from the Cometic gaskets are caused from improper installation. Great care must be taken during installation to make sure the inner rings are perfectly aligned. Also, you need to put a 50-60RA polish on the mating surfaces. We use Cometic gaskets exclusively on 420A and 4g63 engines... I'm talking 25-35 PSI on GT30R, GT35R and GT40R turbochargers. Cometic is the only gasket I use.

This may very well be the case as you raise valid points.
If I'm not mistaken, roughly 3-4 years ago when I was rebuilding my engine, there was at the time an impression that a sealing issue came up in various instances with the outer bolts. There was a post at the time that had the Cometic overlayed w/ stock gasket and there were differences in center line then. Being that they are an innovative company which has grown over the years in popularity, it sounds like this has since been remedied, or it may have been an isolated case in production. Either way, there is no contesting the fact that these have since held 25+ psi with "big" turbos as Doug stated.


--------------------------------------
Santiago
boosted 420a...(2.2l v8 eater)
02 WRX
95 T/A 383ci
03 Harley XL 92ci w/ NOS

I doubt this is your issue but a leaking waterpump o-ring can cause your coolant to be forced out of your overflow tank too. When the pump is running it can suck in air and force the coolant out. When the waterpump isn't running (ie: car is off) you'd have coolant coming out of the leak if this was indeed the issue. Like I said, doubt its your problem but I figured I'd just throw this out there for anyone else searching who may have a similar symptom.

Originally posted by jack_of_trades
I doubt this is your issue but a leaking waterpump o-ring can cause your coolant to be forced out of your overflow tank too. When the pump is running it can suck in air and force the coolant out. When the waterpump isn't running (ie: car is off) you'd have coolant coming out of the leak if this was indeed the issue. Like I said, doubt its your problem but I figured I'd just throw this out there for anyone else searching who may have a similar symptom.

You might rasie a valid pint but it is unlikely that what you explained is the problem. It is not nessary for coolent to be leaking from the engine to know that it is a blown headgasket. It may not be(a blown headgasket); however, I am quite sure that this is the problem. When there is boost pressure there is an effective increase in compression inside the cylinder thus forcing the combustion chamber gases into the coolent passages and then forcing coolent out into the overflow. I know this is happening becasue when I boost I can hear the belt squeeling indicating that the coolent is overflowing onto the belt. And just so someone doesnt say that mabye a belt is loose they are properly tensioned and did not squeel before this problem. Also at idle it is evident that there is air comming into the coolent overflow.

Just throwing this out there, not saying it applies to 420a's. I built a motor for a focus (2.0 zetec) with arp studs and cometic gasket and the head gasket leaked at 8psi of boost. I called up ARP and they said to tq the head down to 80ft/lbs in one step, none of the 20-40-60ft/lbs stuff. Just hand tight and straight to 80ft/lbs following the stock sequence. 10,000 miles later and its still holding 20psi of boost.

I didnt do that when i built my 420a so i dont know if its a good idea or not for our motors or not, but something to think about.