head shims

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Oct 29, 2002 | 02:40 PM

kuch73

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head shims

Want to shave my P79 .080, but can't find the shims anywhere. Who or where can I find them? Thanks

Oct 29, 2002 | 02:56 PM

L0ki

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Re: head shims

Just use an N42 head ... same end result and a lot simpler

Rusty Datsun x 3

Oct 29, 2002 | 03:07 PM

kuch73

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Re: head shims

Yeah I know the N42 will raise it but I like the chamber of the P79 much better. This is definately the way I want to go. Thanks for the fast reply!

Oct 29, 2002 | 03:15 PM

L0ki

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Re: head shims

why is te P79 much better ?? ... also it has the awkward round exhaust ports .... if you have a look on hybridz.org there is a big discussion on raising compression and that there is no evidance to prove that the P series is actually more efficent in real life ... reguardless of the fact the theoretically the P series is better ..

Rusty Datsun x 3

Oct 29, 2002 | 03:30 PM

kuch73

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Re: head shims

The P heads have the better closed combustion chamber for controlling detonation. The shape of the chamber forces more of the mixture to be squished toward the plug. This creates a better burn and more power. Also the N42's have soft valve seats that are more prone to wear compared to the hardened seats of the P series. I would rather just shave the P79 and not worry about detonation. Just me though!

Oct 29, 2002 | 03:35 PM

L0ki

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Re: head shims

If you are interested
http://www.hybridz.org/ubb/ultimateb...;f=12;t=000919

Rusty Datsun x 3

Oct 29, 2002 | 03:48 PM

Spudz

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Joined: Mar 2002

Posts: 646

Re: head shims

Kuch 73,
Check with your local car parts store like NAPA.
They should have bulk shim stock or be able to get it for
you. Also a local engine machine shop should be able
to help you.

Mike

Oct 29, 2002 | 03:50 PM

kuch73

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Re: head shims

Wow, my first night on and already into it! That forum seems to go back and forth alot. Some say P79, some N42. Shaving a P79 is not that bad. Just shim up the cam towers, shim the valve springs, and use 75-78 valves which are .080 longer. All geomatry is back to norm and better chambers. I know this is my own opinion, but look at just about every after market head manufacturer's designs. They will use a chamber that pushes the mix to the plug, this is just better efficiency.

Oct 29, 2002 | 03:51 PM

Spudz

Registered User

Joined: Mar 2002

Posts: 646

Re: head shims

[img]/w3timages/icons/smile.gif[/img]

Loki,
His question was where to get shims, and not
what head was better . I would like to see what results
he gets from a cut P79 head. I always felt when you cut
them you loose some of that effeciant chamber area,
but I am not a L Engine head expert.

Mike

Oct 29, 2002 | 03:54 PM

#10

L0ki

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Re: head shims

yeah thats what i thought Spudz .. just sounds like the P79 is a lot of trouble for a small difference

Rusty Datsun x 3

Oct 29, 2002 | 03:54 PM

#11

kuch73

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Re: head shims

Thanks! I tried the local parts places, not NAPA though. I'll stop by the machine shops, see what they have.

Oct 29, 2002 | 04:00 PM

#12

Spudz

Registered User

Joined: Mar 2002

Posts: 646

Re: head shims

Try this link out http://www.napaonline.com/
Type in " shim stock" and it will gove you a bunch
of thicknesses and nad materials. My friends had
a roll of it that came in a tin that they used.

Mike