how buch boost B4 O-ringing

[mat vsII]

Hi guys. I’m looking into building the engine for my VL wagon project car. I was going to O-ring the block and run about ~24 psi
But the only issue is when an O-ringed engine lets go it tends to completely shag itself, rather then blow out a gasket or something.
So I’m thinking of not o-ringing the block and running a bit less boost.
How much boost can you run without O-ringing?

Anyone had much experience with this?

[VN_Luke]

I've done a fair bit of experimentation with the rb30's, have found (from MY personal experiences/setups etc - so remember that opinons and experiences will vary greatly!)

- a stocker gasket and bolts will stay put with at least 14-15psi up it, but is VERY happy to let go quickly at the first sign of detonation.

- I've never really ran more than that on a stock gasket because I've never really managed to get through the tuning process for more boost without busting a stock gasket

- my busted stocker gaskets tend to just 'stretch' the flame ring into the nearest water port (have done 3) There's no sign of the flame ring being eaten away at or anything. just "stretched' - I guess that could mean that the head is lifting?

- recently I was running up to 27psi on a stocker RB30 wrecker special, but fitted with a cometic 3 layer steel gasket and ARP head studs with no signs of failure in a few thousand km's worth of [ab]use.

- When I finish building my 'good' motor, I'm going to be using a cometic 'phuzion' [linky clicky clicky] gasket and anywhere into the 30psi+ territory, presuming the fuel and setup can support it. It looks like a very interesting alternative to O rings.

- I've heard (never experienced) that copper gaskets + o-rings are a bit of a bitch on a street car - they apparently tend to weep water/oil when cold, etc.

- I've also heard that a lot of the VL guys have had great success with O-rings and a standard genuine nissan gasket.

So far I haven't gone with O-rings due to the expense of machining them, and the fact that you can't just mix and match heads/bottom ends/etc without re-machining for o-rings/recievers.

The bottom ends are pretty strong - in my opinion, strong enough not to put yourself through religious gasket changes to try protect a bottom end. - just make sure it's not 'knocking it's head off' (lame pun intended) and she'll be right.

my recommendation would be wind the boost up and run a MLS gasket + good quality head studs.

happy boosting!

[mat vsII]

Thanks for your advice. I mite steer away from the o rings. I guess I'll probably start around 15 psi then just creep it up and see how it lasts.