4.160 head gaskets?

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Apr 20, 2021 | 11:39 AM

gkull

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From: Reno Nevada

2024 C3 of the Year Finalist- Modified

4.160 head gaskets?

The waiting is killing me along with my torn rotator cuff and one bicep tendon. The joys of working under race cars for to many years. Like months to acquire. My bore is 4.155 and my previous head gaskets were Cometic C5247-027 It's a MLS .027 thickness. My quench is better this rebuild. I had the block decked to end up with .015 piston down the hole. So .042 quench is pretty good.

Iron block and aluminum heads.

My question is does anybody know of a source for similar Multi Layer Steel. I've had solid copper fail in the past and I don't want a typical FelPro because of 11.7 C/R

Apr 20, 2021 | 01:08 PM

Jebbysan

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From: New Braunfels Texas

The Fel-Pro 1143 is a MLS gasket....4.165 bore/.041 thick.....Summit has them in stock.

Jebby

Apr 20, 2021 | 02:06 PM

gkull

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Quote:

Originally Posted by Jebbysan

The Fel-Pro 1143 is a MLS gasket....4.165 bore/.041 thick.....Summit has them in stock.

Jebby

Thanks, but the quench might kill me. .041 + .015 = .056

Apr 20, 2021 | 02:26 PM

gkull

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Oh, I did stop at summit this morning and i have the .027 on order. Summit didn't have valve clearancing clay. I installed the cam 4 degrees advanced from where it was before basically 4 degree retarded for broader TQ curve and top end power. I'm not really worried about valve clearance because I am going to only 1.6 ratio intake and possibly even 1.5 on the exhaust.

cam lift I = .403 E= .420 .403X1.6 = .645 .420X1.6 = .672 then you minus the lash factor to get net lift. .012 I and .014 E Hot lash.

It was just too hard on the springs with the endurance road racing type lobes even with only 220# on the seats.

Apr 20, 2021 | 04:30 PM

HeadsU.P.

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From: Cool Northern Michigan

As far as the "Valve Clearance Checking Clay:" Its repackaged in the toy section at Walmart. Its AKA Silly Putty.

Years ago, it was common practice to put the 1.6 rocker on the exhaust side only. The theory was and still heard today, that Chevys suffer in exhaust evacuation.

Who knows !!! ???

Apr 20, 2021 | 05:45 PM

76strokervette

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From: Willoughby Ohio

Cometic should make whatever you want I just don't know what the lead time would be.
Maybe give them a call.

Apr 20, 2021 | 06:40 PM

gkull

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Quote:

Originally Posted by 76strokervette

Cometic should make whatever you want I just don't know what the lead time would be.
Maybe give them a call.

I already called them. Summit racing was cheaper at about 175 with tax

Apr 21, 2021 | 02:43 PM

gkull

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Quote:

Originally Posted by HeadsU.P.

Years ago, it was common practice to put the 1.6 rocker on the exhaust side only. The theory was and still heard today, that Chevys suffer in exhaust evacuation.

Who knows !!! ???

I'd tend to say that is wrong for modern aluminum heads. Some of them like mine flow over 240 cfm. Of course they are primary pipe limited to about 1 7/8th. I hogged out the inside of the pipes to become a little bigger for some anti-reversion help.