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the ultimate head?


kiznook

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I'm planing my super special L motor build. But I need to decide, what should I do with the head? This will sound VERY noob-ish, but I figure I'll ask in public, and help contribute to the content of the site with an informative thread.

 

likely build:

1.5" ports

Z valves - what are the specifics on these? worth it?

Mild cam - what is best? street car, mild revs, decent compression N/A

 

Peanut or open, yet to be decided, Is there any open head that is better than the others, or are they all pretty much the same?

 

At what point with a cam do I need to replace the rocker arms, springs, lash pads? and how do I know which ones I need?

 

QUESTION #2:

what head gasket is used for 87+mm bore?(z22+) Do you modify the Z gasket and use the L timing cover portion?

 

brainstorm..... ENGAGE!

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http://www.the620.com/html/tech/partnum.htm

 

get a 1.5 inch port intake manifold and match port the head to 1.5 inch(SSSspec)

not the Cannon brand 1.25 inch unless our keeping the head 1.25 intake

 

On a L16/1820 use a closed chamber head

LZ hybrids many use the U67 open chamber head which is 1.375 and ez to open up.

 

Nismo head gaskets are expensize. Bryon510 knows what to do on the 510realm for the front cover/head gasket set up ask him.

 

As for the Z valves if you got the money and trust the machinist to install everything perfectly But in my OPINION here I would not worry about the 1.73 valves. It adds cost/work for a 10-15% increase in area size. I think money can be betterspent of a good. I say GOOD set of sidedraft carbs.

cannonnismointakesize_thumb.jpg

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At what point with a cam do I need to replace the rocker arms, springs, lash pads? and how do I know which ones I need?

 

QUESTION #2:

what head gasket is used for 87+mm bore?(z22+) Do you modify the Z gasket and use the L timing cover portion?

 

new cam = new parts! measure 2X and order accordingly. i started w/ manuf recommendations(isky) on the lash pads. easy to change if needed.

 

i used the nismo 88.5mm HG for the LZ22(i have the part# if needed) have not installed, but it shouldnt need any mods.

 

i went w/ the U67 (open-because i had it, and 2 spares) ported w/ bigger SS valves installed

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Stock open head... 8.5

P nut head........... 8.9 (just under) Not enough difference to cause much pinging and well worth the larg quench area that homogenizes the fuel/ air mix anyway and promotes more eficient burn, more even cylinder temps, less hot spots that lead to pre ignition in the first place. All other things equal on a stock displacement L20B... go P nut.

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well, It's likely going to be a longrod 2.1, or just a lz22. Unless I can find a set of DCOEs, I'll be sticking with the DGV for a while (future upgrade on same motor) I probably won't use the big valves, like Hainz said, it'll be a lot of work (money) for little overall gain.

 

I'll probably port it out to 1.5" and possibly work the factory manifold over a bit as well (until I can find sidedrafts)

 

hmmm....lot's of thinking to be done, and reading!

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yeah, I saw that. "Pending pickup" he probably wouldn't go for a $500 shipped offer :D And like I've said before, I have a sweet hookup on weber parts and tuning help. with everyone telling me webers suck, I'm surprised there isn't a bunch of people trying to sell them

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