Hey guys, I picked up a super e and I'm planning on a turbo build. Just one quick question. I am planning on running around 15 psi on Miller's war chip, maf, and Injectors. The rest is going to be home brewed.
With the compression ration of an e to I swapped motor and a super e motor only being about .3 off, would there be any point to changing heads on my current motor?
boosting a super-e
The differences are the cam and the valve springs. I'm a little unclear on what actually came on the super eta and at what dates, but all super etas came with the 885 head casting. I believe at some point it came with a 4 bearing cam instead of a 7 bearing, so you had to drill out the extra feed holes for 3 of the journal bearings. If you have a 7 bearing cam already (as all of mine have) the journal feeds are already drilled, so you can just swap in the b25 cam and double valve springs. It is often easier to just find a complete b25 head anyway though. I started collecting 885 heads when I was thinking about doing my swap, rebuilt one of em and just swapped it on.
The only difference between the super eta and what the 2.5 head is the camshaft and inner valve springs. The compression ratio is the same if you bolt on a 325i head since its the same head casting. The super eta pistons have deeper dishes than those used in the B25 motor, so you get slightly lower compression.
You could bolt on a complete B25 head but you would bet better off buying a new B25 cam and a fresh set of rockers and shafts. You can get a cam on eBay for under $200. The B25 intake and throttle body are common and cheap and bolt right on as well. Your head will probably need to be drilled but its a simple operation that can be done by hand. Doesn't have to be perfect.
You could bolt on a complete B25 head but you would bet better off buying a new B25 cam and a fresh set of rockers and shafts. You can get a cam on eBay for under $200. The B25 intake and throttle body are common and cheap and bolt right on as well. Your head will probably need to be drilled but its a simple operation that can be done by hand. Doesn't have to be perfect.