m20 head question

[droid01]

OK i realize this is more of an e30 question but i know there is a few guys on here that have the conversion and or e30's, so here it goes.

I've got a 83 euro 323i m20 installed in my 74 2002. i had the head ported and polished and had larger valves installed, along with a 272 regrind from ireland. Anyways my car overheated due to a bad water pump and the head developed a crack. I know this because my mechanic pulled the valve cover and pressurized the cooling system and was able to get coolant to ooze out. a little puddle formed inside the head. my oil also looked like chocolate milk due to water. So hear is the question. I'd rather not have the head welded, and if i get a new head from a 325i i believe i will be loosing compression. the 323i head is a high compression head and my block is only 2.3 so by moving up to the 325i head from a 2.5 block i believe my combustion chamber will be larger thus lowering my CR.

Now ideally i want to upgrade my whole system to the 325i motor with motronic because my current motor is l-jet and only a 2.3. but i dont have the money to tackle this motor swap right now so what is my best option for dealing with my head. whats the cheapest thing i can do to just get the car back on the road for a few more months till i can tackle putting a new motor in. should i just get the car home and park it and save my money for the motor swap or find a cheap head and throw it on for the time being. all suggestions welcome

[E21kiwi]

You could look for a E21 320/6 or 323i head with the 200 casting and bolt everthing up ok and there should be a few of those around for cheap over there. If you feel inclined you could grind the ports out to match the L-jet inlet manifold and you will be good to go. I know the M20B23 731 head is not common in the US so that is probably the best bet for little money rather than fork out for an M20B25 885 head.

In the long run you will want to go M20B25 motronic and if you have the 272 cam, look for a M52 E36 crank from a 328i and that drops in sweet, use your 2.3 130mm rods and you will have a mean M20 that will blow the 2.3 into the weeds...220 bhp!

epic link here: http://www.e30zone.net/e30zonewiki/index.php/Building_a_2.8

[Guest Anonymous]

read on e30 tech the 200 casting was the most restrictive head. i would think the m20b25 head with its lower compression would still be better because it flows so much better. just guessin.