2.9 corrado metal head gasket

[sparkz 0]

As above guys. I am now running a 2.9 bottom end as i had my 2.8 block rebored with forged pistons to 2.9 spec. I bought a metal head gasket for a 2.8 but as the bore size is now slightly larger, will i need to change the head gasket (i think i will :roll: ) to 2.9 spec? Is there a company that make an o.e head gasket in metal. I dont really want to go for a spacer gasket as the comp has been lowered already due to the forged pistons.

 

Cheers in advance!

[CorradoVR6-Turbo 0]

Just get the MK4 VR6 head gasket mate,its a three layer metal gasket,it fits the 2.9 with no problems.

[sparkz 0]

Cheers mate! How's your turbo route going?

[CorradoVR6-Turbo 0]

Just waiting for ATP to send most of my bits then its just a matter of bolting the bits on,then i can start to play!!

 

By the way the part number for the metal HG is 021 103 383N

 

What Turbo and manifold you running sparkz?

[Kevin Bacon 5]

That's a good point, do the cylinder rings in the gasket mate right up the cylinder walls or is there a gap? I guess they don't, but I've gone from 82mm bore to 83.5mm and that wasn't flagged up when Stealth built it, so I guess one gasket fits all :-)

 

I think Sparkz likes his midrange torque like me, so won't be going for a massive turbo!

[Rpmayne 0]

83.5mm bore, is that right? Thought 82.5mm gives 3.0L and 83.0mm gives 3.1L?

[Kevin Bacon 5]

Aye, 83.5mm bore gives 2967cc.

 

82mm gives 2861cc

 

82.5mm gives 2897cc

 

83mm gives 2920cc or something, haven't worked that one out yet.

 

it's crank stroke that gives 3.1

[VR6Will 0]

I think Sparkz likes his midrange torque like me, so won't be going for a massive turbo!

 

i believe he's going for a gt35r

[JIMMI 0]

Girl, whats wrong with a T70 ?????????

 

Ha Ha !

Jimmi..............

[Kevin Bacon 5]

:lol: T70 is for men only, LOL!

 

I like my girly GT30 :-)

 

35R is a lovely turbo. With a .63 turbine AR it will spool like a GT3071..... nice 8)

[Rpmayne 0]

Gotcha, so my 82.5mm is only abit closer to 2.9L then. :( Sounds wicked what you're doing with yours, when are you going to try super and turbo charging together? :)

[Kevin Bacon 5]

Yeah yours is a true 2.9 now, instead of a 2.8 and a half :-)

 

Cheers!

 

Yeah I thought about compound charging and I reckon an electromagnetic air-con pulley system could work to decouple the supercharger at a specific rpm, but maintaining Alternator, water and PAS drive. Then the turbo takes over 8)

 

An rpm signal from a schrick controller would manage that easily :-)

 

As for supercharger choice, it would need to be a Rotrex as the Vortechs don't deliver enough low end boost to make it worthwhile. Ideally you'd want 3 or 4 psi right from idle, rising to 10 or so by 3500rpm and then cutout.

 

The downsides are turbos are throttle position, load AND rpm sensitive, so it might interfere with the charger when not needed. And when the super engages and disengages, you'll get a quite a shunt through the drive train.

 

And the pipework, intercooling and mapping would be fun!

 

I bet VW's 1.4 twin charger is much more complicated than it looks!

[sparkz 0]

I think Sparkz likes his midrange torque like me, so won't be going for a massive turbo!

 

i believe he's going for a gt35r

 

Yep, gt35r it is!

[CorradoVR6-Turbo 0]

Ditto,but with .82 exh AR.

[RS VR6 0]

Be aware that the Mk4 headgasket will bump your compression up, from 10:1 to 10.5:1.

[jonrb 0]

Be aware that the Mk4 headgasket will bump your compression up, from 10:1 to 10.5:1.

Indeed. In fact, for NA installs that's an advantage. Vince has just offered me a thinner metal gasket as a NA tuning option because it raises the CR.

 

Has anyone else done this and able to comment on it?

[CorradoVR6-Turbo 0]

It does raise the CR but it hardly makes any difference at all.Not worth it IMO

[jonrb 0]

The head is going to be off anyway and the gasket is going to be changed anyway, so it's more a case of "why not?" than anything.

 

The only downside is that I'll need to run on Super-Unleaded whereas for the past 10 years the car has run on nothing but standard 95RON.

[CorradoVR6-Turbo 0]

why only super?

[jonrb 0]

why only super?

I dunno. That's just what Vince told me. Maybe the slightly higher CR makes it more prone to pinking? Or maybe the only way to take advantage of the slightly higher CR is to map the car to need SUL otherwise there is no gain? I suspect the latter.

[CorradoVR6-Turbo 0]

I cant see .5 of a Cr increase needs super,that's just crazy,its not worth the raise in fuel costs for a steel gasket that hardly makes a difference,anyway my mates VR runs unleaded all day long with no difference in performance at all so im sure you will aswell.

[jonrb 0]

I can only guess that Vince intends to map the car to run on SUL only.

[RS VR6 0]

I thought he mentioned that he's going turbo or has a turbo. Raising compression on a turbo motor is normally something you don't want to do.

 

For turbo you'd probably want to bring compression down to 9:1 or lower depending on boost level. If your running low boost stay with stock compression.

[jonrb 0]

I thought he mentioned that he's going turbo or has a turbo. Raising compression on a turbo motor is normally something you don't want to do.

True, but I confess that I've slightly hijacked the thread and we were talking about NA use in that instance. :)

 

Yes, for turbo installs you don't want to raise the CR, in fact you often want to lower it.

[vdubjb 0]

It does raise the CR but it hardly makes any difference at all.Not worth it IMO

 

The stock fibre ones arent as well made. The metal ones are tougher and not much more expensive. The slight bump in power is worth it too.