SR20 Head Upgrade Questions - Page 2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

codyace · 10-14-2010, 01:42 PM

Quote:

Originally Posted by Blacklines86

Assuming one is already following Codyaces recipe for a 400+ HP SR, I have a couple head questions.

What advantages are there to upgrading to aftermarket valves, and valve guides besides extra strength? Can better flow can be expected from +1mm valves? Or are valve upgrades unnecessary at the 400-450 hp range?

IMO It's really not needed and simply an unnessecery step if you're looking at anything this side of the 450-500 range. The stock valves are known to work, and there is limited to no proof of a larger valve (1mm) making any significant difference.

Race motor? Maybe. Super big power? Maybe. But truthfully saying, most of what we are driving/building/owning are street derieved cars. To me (and albiet maybe simple minded), you can't 'beat oem' when it comes to street based setups. Upgrade what you need to, and leave the rest.

Blacklines86 · 10-14-2010, 06:04 PM

Right on man, thats what I figured, but I wanted to verify with someone who knows what they are talking about.

Just one more question, I have read that if you have your head milled, that is can retard timing, and it is necesary to use adjustable cam gears to correct this. I am planning of having my head decked if required. If not, then would you say the JWT cam gears are the way to go?

Codyace, I am planning on following your build very closely when I put my SR20 togethor, and I appreciate the time you take to answer questions.

cotbu · 10-14-2010, 06:30 PM

Quote:

To me (and albiet maybe simple minded), you can't 'beat oem' when it comes to street based setups. Upgrade what you need to, and leave the rest.

Words to build by!
Cody has a proven setup and you really can't go wrong...until you start to substitute!
I've seen alot of "codyace setups" that are so off base, it's been a pleasure to work on! Since when did codyace have the engine harness laying over the valve cover, or a 38mm waste gate welded to a Megan manifold!

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10-14-2010, 06:04 PM	#32
Blacklines86 Zilvia Junkie Join Date: Mar 2010 Location: Japan Posts: 305 Trader Rating: (32) Feedback Score: 32 reviews	Right on man, thats what I figured, but I wanted to verify with someone who knows what they are talking about. Just one more question, I have read that if you have your head milled, that is can retard timing, and it is necesary to use adjustable cam gears to correct this. I am planning of having my head decked if required. If not, then would you say the JWT cam gears are the way to go? Codyace, I am planning on following your build very closely when I put my SR20 togethor, and I appreciate the time you take to answer questions.