N/A tuning potential. How far can you go?

General discussions on EJ9 and D14 improvements. How far can you reach?
Law_
Posts: 1154
Joined: Wed Aug 05, 2009 3:37 pm
Location: Portugal

Re: N/A tuning potential. How far can you go?

Post by Law_ »

I was trying to discover how much compression will increase, by fitting D16Y8 head in D14A4 block. i always have some sort of problem to fill in the tables, but Dodo helped a lot with the new values. Thanks

So i fill in this way:

Block
: Bore 75mm - Stroke 79mm
Head: D16Y8 - CCV - 32,80cc per cylinder
Piston: Other : -5,4cc per piston
Head Gasket Thickness: D16Y8 (2 layer) :evil: 0,025in
Piston to Deck Height: 0?

So calculations gave me : 9,5CR
Displacement 1396cc

I want a stable compression at 10:1CR at least.
I've discovered that removing the head gasket in the table ( = milling the head 0,025in or 0,6mm ) would bump the compression to 10,14 wich is perfect. what do you guys think?

hondaNickx
Posts: 713
Joined: Wed Aug 05, 2009 1:06 am
Location: Belgium

Re: N/A tuning potential. How far can you go?

Post by hondaNickx »

I would use a stock 3 layer Y8/D14 head gasket and mill the head 0.030" and you've got 10.22 :1 Cr.If the head gets a revision you could use aftermarket high compression valves to bump up the compression a little more ( about 0.2 cr with stock size valves)
Keep in mind that this is Static compression and if you fill out the elevation box on the zeal calculator you can see how much difference it makes if you're living a lot above sea level or not.
In my case we/i are living ~625Ft above sea level so the correct (effective ) compression ratio would not be 10.22 :1 but 10.10 :1.
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

Law_
Posts: 1154
Joined: Wed Aug 05, 2009 3:37 pm
Location: Portugal

Re: N/A tuning potential. How far can you go?

Post by Law_ »

Impressive. so Dodo, living in the Netherlands is lucky :D And Saxophonias is not bad either in Greece ;) I also agree that using a 3layer gasket will be better ! whats the limit for milling the head?i've heard it has one mark and you cannot mill pass there ! Cheers

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Dodo Bizar
Site Admin
Posts: 2009
Joined: Mon Jun 22, 2009 10:36 pm

Re: N/A tuning potential. How far can you go?

Post by Dodo Bizar »

Mark should be there on the cylinder head, but never saw it myself. Since I still got a few heads lying around I should try and look for it. Indeed I am very lucky, virtually I'll never be over 20 to 30 m above sea levels. My drag race lane is pratically at zero.

But then again driving in the Swiss Alps is painful...

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