TeeScooby

Just wanted to ask if anyone knows why Version 4 heads are better then the Version 1/2 heads.

What's the difference in power? Cams? And/or fitting?

Thanks guys!

Rbon91

iTrader: (6)

v3 have high lift aggressive cams..

got a long engine for sale

TeeScooby

Does that count for V4 aswell?

And what do you mean exactly by aggressive cams?

Rbon91

iTrader: (6)

Not 100% on version 4...

higher reving I think

Dmacnz

I just put V4 heads on my V2 after rebuild. Seems to be alot more torque low down. Also revs to 8k vs 7k! I think the V2 crank is still a limit on revs though

TeeScooby

I have the 2.5 sti crank in my car along with a whole 2.1 stroker build by Alan Jeffery Engine Tuner.

Just wanted to know the pro's and Con's of the V4 heads

Rbon91

iTrader: (6)

What year is your car? If its newage best sticking with avcs heads

TeeScooby

K reg. 1992. Fully closed deck block

Rbon91

iTrader: (6)

Nice mate.. if you want this v3 engine for the heads you can have it for 350 delivered

Kwik

iTrader: (10)

Are they STI heads you have though? I'm not 100% sure if the STI heads were shim/bucket or hydraulic like the WRX heads.
The V4 STI heads have the same cam's as the V3 only the V4 seems to have one line through the L4IN etc on the cam whereas the V3 seems to have 2.

I believe them to have the same cam profile (apparently the most aggressive?) V3 and 4. I took a measurement of my V4 cam's when I stripped them....

Kwik

iTrader: (10)

If that's including the heads that's a bargain.

TeeScooby

The heads I had on the car where hydraulic and where the ones that came from factory on my car.

But now I am going for V4 hydraulic heads.

Does aggressive mean a naughtier sound or faster car? Lol just confused on the meaning aggressive lol

Steve Whitehorn

iTrader: (13)

OK to clarify....
V3 and V4 STI heads not UK or WRX have the most aggresive cam profile and underbucket shims. Stronger and make more torque. V3 have the reputation as being slightly more aggresive than V4 but I have never met anyone that can prove this.

The identification using the line marks through the cams is not fool proof as they do vary

Beware of people passing off V3/4 WRX heads as STI!

A bit more info for you

V3 casings markings -
Passenger side - top 07 japan - bottom LH B tk 07
Drivers side - top 04 japan - bottom RH B tk 04

V4 casings markings -
Passenger side - top 02 japan - bottom LH B tk 02
Drivers side - top 01 japan - bottom RH B tk 01


The markings on the v3 cams -

Drivers side:
Inlet LB R4IN and 2 R4IN
Exhaust LB R4EX and 4 R4EX

Passenger side:
Inlet KG L4IN and 4 L4IN
Exhaust M4 L4EX and 3 L4EX



Markings on the v4 cams -

Drivers side:
Inlet GE R4IN and 2 R4IN
Exhaust G2 R4EX and 14 R4EX

Passenger side:
Inlet FH L4IN and 2 L4IN
Exhaust GF L4EX and 4 L4EX

The cams usually have lines through the numbering. However not always but virtually always!

Kwik

iTrader: (10)

I'm not sure there's much difference between the v4 wrx and the earlier wrx cams. Why don't you go for Sti ones, I've seen them going for about £200. Alternatively buy rbons complete engine, that will save on head gaskets, stem seals etc.

What is it you are wanting to do bud.

Steve Whitehorn

iTrader: (13)

Just to say reading my post....all that marking line stuff is a bit confusing.
The best clear cut way to ID them is to look at the markings on the Inlet and Outlet valves.

Kwik

iTrader: (10)

I'm fairly sure my V4 cams didn't have the ID you've listed above.
JayAllen is pretty good with identifying these heads.

Steve Whitehorn

iTrader: (13)

My V4 heads are off the car. But I am not near them so can not double check.
Perhaps JayAllen can clarify then.

Kwik

iTrader: (10)

rossyboy

iTrader: (8)

His engine is in the for sale section. It's that price because the bottom end is knocking

You can pick up a set of these heads for £250, so the price for the long engine is about right.

Rbon91

iTrader: (6)

https://www.scoobynet.com/showthread...0#post11281830