M20B28 K-jet build

[niske]

Hi everyone!

I want to hear your opinions and have a discuss about this combo:

M50B28 crankshaft (fabricated to match the seal)
E30 325i M20B25 block (WUR prepared), pistons, head and valves
272 degrees performance camshaft
E21 323i intake manifold ported to match 885 head
E30 325i throttle unit (not sure is it possible, fabricating?)
Porsche 911sc 3.0 air flow meter and fuel distributor (or keep the standard 323i unit?)
Exhaust headers manifold
10,5-11 compression ratio

I doubt that 323i intake manifold will be a bottleneck in here?


Otherwise the goal is to make a stronger M20 with factory outside look and keeping original fuel and ignition system
What power output I can expect from?
I'm open to all of your suggestions!

[Jeroen]

Sounds good! Bottlenecks will probably be the air flow through the intake manifold indeed, and fuel injector capacity. I believe for the latter they suggest using the injectors from a contemporary MB 300E. Same size/fitment but more capacity and also from a K-Jet CIS. Not sure if or how good the throttle body from the 325i fits but I'm pretty sure otherwise there are alternative larger bore TB's. In the end I think you should expect abt 215 bhp.

I take it you want to go this route to retain original looks, or? Otherwise a setup like Mark has done with Jenvey ITB's might bring a bit more flow even. Or throw in a stock M52B28 and have around 215 horses without too much work and for a fraction of the money. Even though BMW told different stories, the average M52 2.8 already gives you an output of abt 215 BHP and there are even simple upgrades possible there like using a M50 intake.

[niske]

I think that finding a MB300E injectors wouldn't be a problem... I`m not sure about 325i throttle body too, maybe M30 one? Need to check that...
You're right, I know about the M52-M50B28 potentional, but I want to keep original fuel and ignition system, some period correct mods and original look overall...
I need to search a little about porting whole length intake manifold, if that's possible at all...

P.S. I'll be pleased with 215hp and lot of torque

[Duracel79]

I ran a 2.7 build on KJet with a 325 inlet manifold. You just need to drill and tap to fit the cold start injector underneath the middle of the plenum.
Then get a bored out (64mm ID IIRC) 325i throttle body and heat up and stretch the kjet boot over it.
Even the 325i inlet can benefit from a little grinding to match the head ports. There is a lot of material around the injector boss's inside the runners.

HTH

Ben

[niske]

I would like to keep 323i intake manifold, so need to find way for grinding...
Do you run standard 323i AFM and fuel distributor?

[323i-killer]

Yes u can still keep the 323i standard inlet manifold best would be to run a porsche 911 2.7 or 3.0 fuel distributor along with some w124 300e injectors for better flow