Things you recommend doing when pulling heads on a ZZ4?
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Race Director
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Things you recommend doing when pulling heads on a ZZ4?
I'm anticipating pulling the heads off a ZZ4 350 because of a suspected head gasket problem. If I end up pulling them off assuming they aren't warped or cracked is there anything you recommend checking or doing to them since they'll be off? I believe they have under 30k miles on them.
Is there a head gasket you recommend? It has a small Weiand 142 blower on it, it sees periodic spirited street use, won't be getting flogged at the dragstrip. I believe the gaskets that are on it now are whatever Chevy put on it.
Thanks!
Is there a head gasket you recommend? It has a small Weiand 142 blower on it, it sees periodic spirited street use, won't be getting flogged at the dragstrip. I believe the gaskets that are on it now are whatever Chevy put on it.
Thanks!
Burning Brakes
Joined: Dec 2017
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2023 C3 of the Year Finalist - Modified
To make an accurate head gasket recommendation you need to know head chamber size, piston contribution to combustion chamber, and piston to deck measurement.
And keep an eye on final compression ratio, which is especially important with boosted motors.
example, I use 64cc heads, with 3.7cc pistons, a piston to deck of 20 thou so I used a 45 thou head gasket for a total of 65. Although quench of 45 is ideal, my motor is built for 300 shot nos at the track. Maybe I left some power on the table, maybe I didn’t, but it hasn’t blown up yet
And keep an eye on final compression ratio, which is especially important with boosted motors.
example, I use 64cc heads, with 3.7cc pistons, a piston to deck of 20 thou so I used a 45 thou head gasket for a total of 65. Although quench of 45 is ideal, my motor is built for 300 shot nos at the track. Maybe I left some power on the table, maybe I didn’t, but it hasn’t blown up yet
Safety Car
Joined: May 2001
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From: Fairfax Virginia
When you source a new set of head gaskets try and find a set made for a "blown" engine. They made "special" head gaskets for the high compression big blocks and they have served me well. If you asked the manufacturer of the blower what they would recommend. Being a SB they should have a lot of choices for the head gaskets, finding the "right one" is the challenge.
Whenever I pull a cylinder head off of a running engine I frequently just pull both heads and then have a machine shop take them apart and verify that they are in good shape. A valve job at 30k miles is not a bad thing and shouldn't cost that much.
Did you turn the radiator on it's head and see what comes out of it yet? How about the engine block plugs?
Whenever I pull a cylinder head off of a running engine I frequently just pull both heads and then have a machine shop take them apart and verify that they are in good shape. A valve job at 30k miles is not a bad thing and shouldn't cost that much.
Did you turn the radiator on it's head and see what comes out of it yet? How about the engine block plugs?
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Race Director
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By "repeat the stock gasket" - do you mean replace it with a gasket that's the same as what came on it?
Last edited by brassplyer; Jan 29, 2025 at 12:21 AM.
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From: Virginia
It look into MLS head gaskets (Often sold under the Cometic name, but they are OEM for Gen III and up, so there may be other manufacturers).
With a blower, a slightly thicker gasket, and slightly less compression, may be a good thing.
With a blower, a slightly thicker gasket, and slightly less compression, may be a good thing.
