Rb20det Head On A Rb30?

[Medium Dave]

Ok, so I have just swapped the motor in my R32 (RB20det) and I have the leftover engine with a spun bearing and I was looking for a bit of a side project. I have been reading the massive RB30DET sticky (up to about pg 80 and counting...) and at the start I am pretty sure it said the 20 head wont fit, but later on there were a few questions which suggest people have used this head. Will I be able to use my head? I realise it will not flow as well, and compression may be too high?, but I have never rebuilt an engine b4 so I dont want to spend a whole lot of money to have it not work (my credit card has melted after this new engine) and after I get it running I could think about the 25 head, thanks in advance

[Sydneykid]

Ok, so I have just swapped the motor in my R32 (RB20det) and I have the leftover engine with a spun bearing and I was looking for a bit of a side project. I have been reading the massive RB30DET sticky (up to about pg 80 and counting...) and at the start I am pretty sure it said the 20 head wont fit, but later on there were a few questions which suggest people have used this head. Will I be able to use my head? I realise it will not flow as well, and compression may be too high?, but I have never rebuilt an engine b4 so I dont want to spend a whole lot of money to have it not work (my credit card has melted after this new engine) and after I get it running I could think about the 25 head, thanks in advance

It (RB20 head on RB30 block) was a common thing (on VL's) back when there no RB25's and RB26's cost a BOMB. Honestly it is cheaper to sell the unwanted RB20 stuff and buy a N/A RB25 cylinder head. The amount of machining and welding necessary to get the water jackets and combustion chamber to fit costs a lot of money, much more than the RB25 head.

Cheers

[Medium Dave]

aah, thanks Sydneykid, I knew you would come to the rescue. I think we all need to chip in and buy you a cape with a big 'S' on it