Im trying to raise compression from 9.1:1 to 9.5:1. I found a gasket that'll tke me to my goal almost perfectly.

http://www.summitracing.com/parts/FEL-7733SH1/

After I ordered them from autozone ($2 cheaper) I started to look into steel shim gaskets and found out they blow easily.

If I clean up my block and head good enough and use plenty of copper spray, will these gaskets last on a cam'd daily driver?

The engine is an lo5 that looked to be in very good condition from the tear down.

 

Im also using brand new head bolts FWIW

 

Man thats risky, Can I ask why you are willing to give up reliability for a half a point of compression? You wont even notice the tiny bit of power you'll gain.

 

I was in the market for a new head gasket anyway since I tore the engine down. I didnt know the risk of steel shim gaskets until after I ordered it.

I was just wondering if it'll hold up since I see alot of people running them from hotrodders.com to people from various forums

 

besides, all the other gaskets I see either lower compression into the high 8's or are way out of my budget. Im talking $80 each

 

You could try them, worst that will happen is they dont seal and fill you cylinders with water which in turn destroys you engine by hydrolocking. Had a friend run those all copper jobbers and they leaked and his rod wound up on the outside of his block. I know gaskts get but spendy but the head gasket is no where to cheap out. Id put MLS gaskets in her and never look back.

 

well I have till the 22nd for the refund so Im going to take a look around, if I cant find anything good enough compression wise, Ill copper these things up and try my luck.

I see millions of mixed reviews about these head gaskets but most of them are in favor of them if you clean up good.

 

Please keep us informed. The more we all know the better.

 

BTW, I have a set of felpro blues that came with a gasket kit but calculating my compression with these drops me down to 8.8:1. I really couldnt live with that

 

Lol why not 9.5 is the max you should run on a iron headed street engine, you can go higher but it takes a big cam to get it done. 8.8:1 is not bad for a street car. I bet you wouldn't loose 10hp, and if you do all the rest you would still have way more power than you do now.

 

Sorry got myself all crossed up between two posts.

 

I am also camming it before reassembly, with all new valvetrain. my cam will have .479/.480 lift. I am trying to squeeze as much power as I can out of just this tear down and cam because im not going to have any money to build up the car after this for a while

 

I understand completely.

 

If you want just a little more insurance against the possibility of the thinner gasket leaking, you ought to buy a pair of Fel-Pro 1094's. They're a steel shim gasket, but they have a thin rubber coating on them. Compressed thickness is only .015" and they're only 22 bucks a piece from Summit.http://www.summitracing.com/parts/FPP-1094/ Or you could use the GM Perfomance Parts '117 gasket and I guarantee it'll seal with them. The GMPP gasket is composition and only .028" compressed thickness. They're only 20 bucks a piece. I used the GMPP gaskets for the AFR aluminum heads on my new 355 and they worked out great. http://www.summitracing.com/parts/NAL-10105117/

 

Ah, the 1094's. I was looking at these but somehow passed them up.

How much more insurance would the rubber coating give me?

 

I think Im going to stick with the head gasket I have for 8.8:1 compression but if I can squeaze some change out Im going to cut down my heads for a little more compression. I want to at least have 9.0:1+ compression

 

Oh yeah, hands down the best/safest way to bump up your compression would be milling the heads. As for the rubber coating on the 1094's, it'd definitely help compared to bare steel gaskets, especially when you're re-assembling block and heads that haven't been newly decked and milled.

 

better safe then sorry. Im gonna get my money back for the gaskets and find out how much itll cost to mill the heads. I remember getting quoted between $25-$50 when searching for a place for my supra heads.

BTW, how low can I take the heads down safely?

 

If I remember right you can cut .040 off before you have to address the intake.

 

If you can find a GOOD machine shop where they actually know SBC's well, they should be able to tell you how far you can mill them. You have to be more careful with the newer SBC heads when it comes to how far you can safely mill them. Just about all factory SBC heads from the mid-70's on up are lightweight castings, so they're more prone to cracking if they're milled too much. The old-school heads from the 50's and 60's were a lot heavier casting, so you could mill a bunch off them. But yeah, if you get them milled down a bit and use the .028" GMPP gaskets, you could bump up your compression quite nicely. Btw, what casting number are the heads you're using?

 

This is embarrassing, 193.

 

 

No worries, that's what I figured they'd be on a L05 motor. Since those are common as dirt, why not mill them some and see what happens? At least you won't feel like you ruined a killer set of expensive racing heads if something goes wrong with the milling experiment! Lol.

 

Ya, the heads arent going to stay but it'll be awhile before I end up replacing them so im going to play around with them.

From a calculator, I can achieve 10.0:1 compression, using the recommended gmpp head gasket, and milling .030.

I am going to find a reputable machinist and tell him to mill as much as possible, but i'd be very happy if I can get away with .030

 

Im pretty sure 10.0:1 on 91 octane will do me plenty good

 

BTW, I got my refund for the steel shims this morning