Heas for Xmas

[grand camino]

Its time i stepped up the head program and let the new turbo breath.I knew it was too big for my combo when i got it but planned to grow into it. Trying to get my mind right on a couple things. I want the best flowing head i can use.Would that be the GN1 alumns...or are the race ported champion irons?    I recall an equation about cubes X head flow= usable RPM range...or something close to that...Also,I understand you need some decent spring pressure numbers to get the RPM's up into that usable range i would have with the new heads.I was thinking 5800 or so.   This is where i get lost.   Would i be leaving too much on the table with the 204/214 i have now?   can it endure any real seat/spring pressure?... and how much would that be 120-140? Dont realy want to go to a roller cam as i thought that 1000$ could be better spent.      any thoughts appreciated.

[Steve Wood]

remember you should raise the compression ration about one point when using aluminum heads to regain the thermal efficiency lost with aluminum heads...I see you claim 9-1 in your sig which is not too bad if it really measures to be that.  Your cam is too small to make use of the potential flow that the heads can provide.  You need something more in the 210-212 deg range to make use of the rpm band.


Personally, I prefer the iron heads unless one is running in the low tens.

[grand camino]

   Thanks Steve, would a flat cam in the range you mentioned be ok?  and is spring pressure a concern i should have. I thought i read that someone makes a cam that is a hardened cam (billet?)  that can endure some spring.

[Steve Wood]

http://www.taperformance.com/proddetail.asp?prod=TA_V264H

TA claims this cam will.   http://www.taperformance.com/proddetail.asp?prod=TA_V264H

I would have thought it might be a bit weak on the top end, but, I don't have the experience to dispute the claim.   I would definitely use TA's lifters as they have claimed their lifters have hardened bases and the picture looks like it to me.  Also I would use the Joe Gibbs break in oil as it is loaded with anti pressure additives for such use.

I would also use TA's springs that they suggest for the cam.

They have a 214 deg cam as well which would sound closer to me, but, it might be pretty soft on the low end from what I remember from years ago with similar cams-might need more converter.

You could ask their opinion.

[grand camino]

 great info,thanks. Can fully ported stock irons reach the same flow #s that champ.ported irons do?   As far as losing some low end power...i felt that with the faster billet wheel spool up i've seen and the added torque from e85 as well as alittle more stall, things would work well together.

[SuperSix]

How fast do you want to realistically go?

[grand camino]

How fast do you want to realistically go?

I want it to be a animal that scares me.  I dont dragrace this one so i cant say how fast. It may make 450 now(@28Lbs.)   I thought maybe 550-600 would entertain me for a while.  I use it to tow my racebike to the track mostly.  It goes 7.70 @174            Any thoughts on heads? thanks.

[Steve Wood]

great info,thanks. Can fully ported stock irons reach the same flow #s that champ.ported irons do?   As far as losing some low end power...i felt that with the faster billet wheel spool up i've seen and the added torque from e85 as well as alittle more stall, things would work well together.

There is nothing magic about Champion ported irons and any other ported iron head.  It all depends upon the quality of the porting as the heads are exactly the same when Champion, or anyone else, starts out.  Good porting is good porting.


If I recall correctly, the Champion heads are cnc ported which means a good hand porter can probably do even better, but, I don't think the difference will be obvious unless one is running nines

[Pyro6]

What intercooler are you using?

[grand camino]

What intercooler are you using?

Its a front mount...probab ly not alot better than a stocker...mayb e a little wider though. Interesting question....wh y?

[SuperSix]

What intercooler are you using?

Its a front mount...probab ly not alot better than a stocker...mayb e a little wider though. Interesting question....wh y?

The best heads won't give you any more power if they can't breath.

[Pyro6]

With all the consideration of cyl. head flow, cam/springs, and the turbo size, if you dont' get enough air to compact, you may be shortchanging yourself.

[Steve Wood]

Mark Jackson was running mid eights on an extended core stock ic.  He might have run fives if he had a real intercooler

[Just a Six?]

remember you should raise the compression ration about one point when using aluminum heads to regain the thermal efficiency lost with aluminum heads
Personally, I prefer the iron heads unless one is running in the low tens.

Steve since mine is just getting started & I now own some Champion Aluminum would you suggest close to 9.5-1? I'm not looking to go faster but I would like to build it properly. Thanks
 
One more thing is I have Victors for head Gaskets but how much would the RJC steel shims affect the numbers?
Sorry to but into your thread but it's all head related for future searches so I hope that's ok.

[Steve Wood]

9.5 would be my target.

I am too lazy to do the math, but, I guess about three tenths with the shims.

You can compute them from here, or find a java equation on line  http://www.vortexbuicks-etc.com/compression_ratio_calculations.htm