Headwork?

[MarkGolf 6]

Is it worth doing any head work?

I'm building a second engine so I can do a quick swap once done and I don't want to turbo my 3.0 block.

I've got a spare head and I'm after a bare 2.8 block which I'll overbore.

I'm starting on my head first, I plan to gasket match the intake and exhaust myself but I'm wondering if it's worth doing anything with the valves, larger or lighter versions? I never really here much in terms of gain and I've never heard of an OEM spec head giving any grief so is it really worth it on a turbo application?

Also, my currently used head and spare head are both 2.9 Corrado items, am I right in thinking that the cams are different to the Golf or is this a rumour? If different, what is the difference?

Thanks

[Phat VR6 3]

Its not needed. you can run 17 psi and still get around 400bhp on a standard head

but with a big valve port & polish head you will get 400bhp from 11psi instead of 17 (ruff guess)

So yes it does improve things. Would also make it more reliable as you can run less boost but make the same power.

Money would be better spend else where like rods/ pistons

What power are you aiming for 300- 400 there's really no point

Trying to get 500 + then get it done

[MarkGolf 6]

Cheers. I'm going to fully rebild a fully uprated bottom end. My current one just has 83mm forged pistons but I don't really like the thin walls when running boost and how I drive..

I want to keept he next block a 2.9 max..

Cheers for the advice on the head, I think I'll just port and polish as planned and big valve it..

I'm only wanting the car to be quicker than my M3 but if talking numbers, I'd want it to have at least 350bhp 370lb/ft..

I'll be going GT30 but depending on how I built the engine I may stump for a GT35. I'm still in the middle fo researching options which best suit!

Just needs to be reliable and capable of surviving my abuse and track days

[Phat VR6 3]

sounds good.. if you got the budget for it then its def worth doing. Your engine will be over engineered which is good.. if you go for the 630cc tune from C2 then your set up should be good for 450- 500 easy

what you going for as far as drive train?

[Phat VR6 3]

just to add it would probably make more sence to spend the money of the big valve head on a o2m gearbox conversion instead

[FishWick 21]

If you're into M3 bashing, I'd go with the GT35R personally.

I would also do the head. Bigger valves and cams do make a big difference. It feels better everywhere in the rev range and it can hold the torque curve flatter to the limiter.

My head has +1mm inconel exhaust valves and +1mm stainless intake valves and I use 263 low overlap cams. I have also run a stock head and cams with a turbo and I won't be doing that again.

The VR6 head is crap for flow, so every little helps.

As mentioned above, I prefer to get my power from flow rather than whacking the boost up.

All I would do in terms of porting is gasket match the intake. Polishing does very little.

[MarkGolf 6]

O2M conversion?? Is that what everyone is doing now? I've been away from this side of things for a while so don't know what the latest discoveries are..The O2M from the R32?

At the moment I have an O2A box with a peloquin, corrado shifter (sits lower), fidanza flywheel and brand new OEM clutch plate.. I doubt I'd go so far as to change the box, I will do the clutch though..

I gasket matched the head over the weekend, I'll probably polish the exhaust side just for the sake of it being an easyjob...

Who supplies decent oversized valves and I take it theyneed machine work to fit, not just a OTT lapping in session? Is it worth while doing springs and followers?

Thanks guys

[FishWick 21]

Mine are Ferrea - http://www.ferrea.com/

Yep, I would do the springs and followers at the same time, as in uprated springs and new followers (INA ones).

O2M is from the R32 / 4 Motion / TT etc.

Easier to get one from a V5 toledo or Bora / Golf as it's the FWD version.

[cabrioman 6]

wot sort of price were they kev ???

[FishWick 21]

I don't know tbh, they came with the head Schimmel Performance built for me :-)

The whole head was $1350 (bought when the dollar was 2 to a pound) fully built with HD springs, titanium retainers and caps, gasket matched intake ports, 3 angle valve job, stem reduction etc etc. Was a real nice job and really made the engine come alive.

[MarkGolf 6]

Bloody hell!

For that amount I may aswell not bother and get it all done for me! I assume that wasn't including the cams, would be a bloody steal if so!

Cheers, I think I'll have to give SP a shout and see what the latest offerings are and sell my head off!

[FishWick 21]

I would. I was right impressed with Bill Schimmel's work on my head. Think there's a picture of it in the DIY turbo thread. He sent me over a new head, so I didn't have to ship an old one over, which was handy.

Nope, no cams. I already had the 263s anyway, but they're not hideous money on their own.

There's no way I could get that spec head done in this country for less than 1500 pounds, let alone dollars!

Say I referred you and he might look after you ;-)

Head weighs 50lbs IIRC, so postage is quite dear, about $200.