As above really chaps, looking at fitting AVCS heads to my v3 classic as its having the new engine built, is there much difference to be had by going for jdm heads over ukd heads?

I appreciate that the JDM have "large ports" and slightly better cams?

I am going 1+mm oversized exhaust valves and some light porting etc along with dual springs and titanum retainers etc, so will this negate alot of the benefit over the JDM heads?

I will use the standard cams that come with the heads.

So JDM or UKDM>

 

I dont really think you'll see or even notice a difference between the two especially if you're doing a bit of work on them anyway.

 

This is what I was thinking, that the cams will give a slight benefit, but seeing as JDM heads command a £2-300 premium over the UKDM ones, thats half way to the cost of a set of cams anyway and I could get something specifically made for my car, not something designed for a 300hp engine!

 

Andy f used the small port uk head castings at either 750 or 850bhp, there is thread somewhere on 22B.com about the difference.

 

I dont even use 22b Ill have a google now and see what it throws up...

 

http://bbs.22b.com/forums/showthread...big+port+heads

For when its back online

 

Thanks dude, I'll have a look at that when its working

Regular port heds it is then!

 

Just to add , smaller port heads are designed for low end torque & throttle response wich is what the 2.5 plays
Were as a JDM big port volumes allow more flow at higher RPM's IE 8000 rpm redline opposed to the lower RPM variant cars
Regards

 

If you could see a Prodrive WRC head, it's based on a V4 head but they cast their own and modify the ports to have smaller inlets, strangley enough the UK new age heads are the same size and shape :-0
I believe it's because there is a big difference between the flow volume inlet/exh on the jdm large port and smaller ports balances things up.
A wrc engine only makes mid 300's but designed for torque of course.

 

Just out of interest interest.how much torque does a wrc engine make?

 

My JDM WRX Blobeye as the AVCS heads as standard and it is a much better and tuneable car than the UK Newage cars I had before.

The JDM car is 250 PS with torque at 245 ftlbs @ 6000 rpm
The UK car is 225 PS with torque at 221 ftibs @ 5600 rpm

Mine as been mapped by Bob Rawle and makes 300 bhp.