AshMurc

hi everyone,

bloody hell been a loosing battle to get hold of specifics about V3 and V5 compatibility and rather then suffer some nasty surprises i WILL now be looking at sticking V3 heads on the short block of a new forged motor with ready built V5 heads.

Re-usung my V3 wrx wagon heads sounds a bit dodgy as the car suffered a bottom end failure and i expect there could have been bits of engine circulating... The entire valve train would be swapped out for the valve train in the V5 heads, so could be cleaned up then, but i have no idea of architecture RE oil galleries and stuff.

So... source different V3/4 heads from a non-wrecked motor or have my old V3 heads cleaned and re-used?

Thanks!

Tidgy

without a thorough check by a specialist who knows what there doing reuse is a risk, just depends on if they are damaged or not

AshMurc

yeah that's what concerns me.

Oops bloody well meant to post this in general technical, sorry!

IainMilford

iTrader: (15)

as above need to get them checked, I had a pair of avcs heads which I thought were ok, but there was a lot of pickup/scoring around the cams and sever cracking around the sparkplug threads which the specialist picked up but I didn't

Tidgy

haha, yeah.

what you do relay depends on budget, ar eyou self buildign or getting it built by a specialist?

AshMurc

Thanks guys, very sensible advice! Tidgy, i have bought a zero mileage 2.1 forged long engine from a very genuine guy on this forum, but it has V5/6 heads (cossy cams and stuff so all that would be getting transferred into the V3 heads) and my wagon is a V3.
The work would be carried out by my local tuning garage (so not huge amounts of budget left but still want to do it right). I guess if i buy V3 heads off a non-blown up car on here for example there is still no guarantee they will be ok

Tidgy

tbh i'd speak to who evers building it, they will give you better advise than on here. Assuming is a decent tuner lol

jayallen

iTrader: (31)

I have some V3 sti heads/cams for sale if you need them fella, also new cometic head gaskets.

AshMurc

Thanks guys. Just thought, will the valve train from the sti V5/6 heads all fit straight into V3 heads??

here's the spec:
Frayz engineering built heads
v5/v6 Sti heads
New Supertech in and ex valves (black nitrided stock size)
New Cosworth 272 cams
New Cosworth single valve springs
New genuine subaru 1.6mm multilayer steel Head gaskets
New seals throughout

so where possible would the above go into V3 heads? If so would i need sti v3over my wrx wagon ones

alcazar

iTrader: (2)

What's the problem using the V5/6 heads?

AshMurc

My car is a V3 so different inlet manifold, loom, coils etc. TBH i have got that lot from a V5 already as only £100 for the lot, but could not find any more info as to sensor compatibility and goodness knows what else and would def need different engine management. Not to mention being scared off in a previous thread!

confused dude, at least this way it is all done and i know my electronics will all still work (provided my question form post #9 is good news!)

alcazar

iTrader: (2)

Tried PM's to the leading tuners, who may be able to advise?
David O'Brien, (API).
Allan Jeffery, (Engine Tuner).
Harvey Smith, (Harvey Performance).

Amongst others.

AshMurc

Yeah good idea, you are a helpfull guy thanks

To answer my earlier question for anyone else that may be interested, no, V3 and V5/6 valvetrains are not interchangeable (different size cam buckets i am told). oh well.......

alcazar

iTrader: (2)

If you can't get and answer and help from at least ONE of those guys, my name's not Alcazar, (on here)

APIDavid

iTrader: (4)

No it won't fit or transfer at all. You need Vers 3 / 4 STI heads. the original cams are good for 550 hp, so no need to worry on that score.

Good Luck David APi