Garage Storage Organization and Garage Cabinets

BLASINTEBO · 08-22-2003, 07:40 PM

I got this felpro copper head shim, because I was planing on milling the head after replacing the headgasket, but I picked up a brand new head instead... and now I have been up to no good... stage 1 port polish, ported polished exhaust manifold, underdrive pulley/resized belts, 52mm throttle body etc., 2 piece intake... I have left the bottom end alone... should I use the head shim so I don't blow it up>? OR will that just defeat the purpose of what I have done? How do changes in flow affect compression? and do all boosts in power/efficiency affect the bottom end?

laserxe84 · 08-29-2003, 08:41 AM

If it truly is a "Brand New" head that's never been milled, you're better off without the shim. You want to be at 8.1:1 CR (stock) even with a lot of mods. Any less and your're relying on a lot more boost to make the same power. Also, IMO, using a shim basically doubles the chance of head gasket failure, although I have never used one before.

Hope this helps

glhsken · 08-29-2003, 08:47 AM

52mm TB is worthless... It will not affect your power output, only your mileage.

If you are that worried about the condition of the bottom end, re-ring the motor.

The mods you did actually REDUCE your risk of detonation, even if power goes up (well not the TB, again no effect)

The copper shim survives 20+ psi of boost nicely. If you do use it, Permatex copper spray sealant....

lametec · 08-29-2003, 08:52 AM

Quote:

Originally posted by BLASINTEBO
should I use the head shim so I don't blow it up?

What kind of engine? 2.2/2.5? How much boost will you be running? On what octane gas?

BLASINTEBO · 08-29-2003, 03:15 PM

I will be running 14 pounds (current) and then up it incrementally to about 18. The head is a new casting, with roller rockers. It's a turbo II (wanabe) 2.2 (GLHS), turbo I bottom end. Rebuilt 525 with hardened case.

Thanks for the tip on the 52mm TB... after reading Donovan's site I have since decided to leave the two piece intake alone.

As for the head shim, I am still up in the air. I want power, but i WANT IT TO LIVE. in THE EVENT OF SOMETHING FAILING, I would much rather replace the head gasket (mopar 2005) than the block (for now... common blockin the semi distant future).

lametec · 08-29-2003, 03:48 PM

No need for a shim at only 18 psi on a 2.2, at least not with 93 octane.

If you only have 91 octane available, maybe.. But still not likely. I don't have any experience running 91 octane, but 93 is good for low to mid 20's at least, so I'm guessing even 91 should do fine without the shim.