: .030" over head gasket?

03-31-13, 11:17 AM
Assembling 2001 n* engine. Had bored .030 over and I am ready to install heads. Has anyone found a larger head gasket or can stock be used? Stock gasket is only .010 bigger than bore and I was thinking it may be close once head is torqued down and squeezes gasket out a little. Any input appreciated. By the way, I am using Northstar performance studs and jake has a great product! And Chris at Rippy got
Me rod and main bolts for $60 cheaper than my local caddy dealer. Thanks guys

03-31-13, 03:59 PM
Check with Cometic or CHRFAB for gasket/overbore clearance. Who made the pistons ? - Arias, Keith Black ?

03-31-13, 04:27 PM
Engine tech pistons. All I was able to find was 3.700" gaskets so that's what I used. Put heads on today. Few more days in the shop and my 3 month project should be out the door!

03-31-13, 04:40 PM
Hmmmmm.... Even with a bit of fire ring squash these engines (your pistons ???) have a few thousandths of deck height, so you should be OK.

03-31-13, 09:32 PM
Turns over fine. They are stock type flat top pistons. I think it'll work. I've seen closer but I'm used to mls gaskets on performance builds. I'm just anal about this stuff and certainly don't wanna see it again! Heads were cut too! Haha. Thanks for the input Sub!

03-31-13, 10:53 PM
What made you bore it? I had always heard that there wasn't much room for boring. Be sure to let us know how it works out.

04-01-13, 06:51 AM
Bore measured .003 out of round and had bad piston slap. Could only find .010 over pistons for early N*. My machinist said it was acceptable and we found .030 over pistons so what the hell!

04-01-13, 10:46 AM
What were these pistons originally intended for?

04-01-13, 11:02 AM
Northstar. There are about 4 piston makers producing them. Engine Tech gives the part numbers for Arias and two others ........

Google it - "engine tech pistons".

04-01-13, 04:37 PM
You said u could only find 010 pistons for northstar BUT u found these that are 030? That implies these were not spec'd for northstar to begin with.

04-01-13, 06:16 PM
My bad. that came out a littl goofy. What i meant was , we could not find .010 over pistons for later N* so we had to go .030 over. We found .010 over pistons but were early design so i couldnt use them in my 2001 engine. would've been nice to only go .010 over but had to work with what was available quickly. Thanks

04-01-13, 09:43 PM
Sub, You seem to be pretty savvy with these engines....Is there an "O" ring that goes in the groove on the back of the oil pump where it meets the block? I do not remember seeing one upon disassembly but thought i'd ask. thanks for the help man

04-01-13, 09:50 PM
I don't see one in this diagram (#425 is a spacer).


04-01-13, 10:27 PM
Wonder what 425 is? The drive sleeve?


Spacer behind oil pump hub? Don't remember that guy!?

04-02-13, 08:03 AM
I'll bet it's a poor rendition of the drive sleeve. What does the text page say for the number ?

www.gmpartsgiant.com , 2001 Seville, engine, oil pump and assemblies

It's included in #423, oil pump. They call it a spacer.

04-10-13, 12:33 PM
Well, she fired right up last night. Ran for about an hour. No leaks, no knocks/ticks, or lights. Good day! Used a garden sprayer to prime it. worked great. Bleed the brakes and charge the air and we're back on the road

04-21-13, 05:13 PM
Thanks a lot for your help when I was in need submariner, she's got 500 miles on her and stronger than ever!