Help with my first engine build?

[AlexMaldonado]

So I'm considering buying an M20 block and building it up to put in my 318is. I've got no legitimate idea of everything I'm going to need to build it with. What will I need aside from a cylinder head kit? What cam would you recommend for daily use with a bit more beef? What size injectors should I use? I'm open to any and all suggestions. I don't have a ton of money to work with, but I've got an okay budget for a couple upper-end components. Thanks.

[ThatOneEuroE30]

Id rebuild the m42 to keep it original. Otherwise Build a 2.7 stroker 325e bottom end with an i head with a 272 cam. As for the bottom end get some new oil pump rotors, bearings and rings, gaskets, get a new idler pulley don't want the stamped one in there.

[ForcedFirebird]

Honestly, I would love to build a high strung m42 for a 318, but power per dollar isn't there, so the m42's we pull always get sold cheap by the owners to help fund their swaps.

As far as an m20, what kind of budget are you aiming for? Keep in mind, you will really want the whole drive train from radiator to diff, and electronics/wiring to swap.

Start with an m20b25, the 2.7 bottom and 2.5 head is only an upgrade if you are starting with an eta car, the head can be changed without pulling engine.

Only two ways to make a cheap stroker 2.7 that will out power a stock b25. 1. Use 2.7 crank, 2.7 rods, 2.5 pistons and shave the block deck to zero the height. Then you have a ~9:1 2.7 with matching chamber/pistons. 2. Locate a rare one year only 1988e engine. It is a 2.7 with 2.5 head but had single valve springs and unique cam. Swap springs/cam/ecu from a 2.5 into it and you have an 8.5:1 2.7 with proper pistons/chambers. They will make ~175-ish and ~165-ish hp respectively pending condition of used parts. The 2.7 with 2.5 head will struggle to make over 140 and a really tired/worn stock 2.5 will do the same.

A healthy used stock 2.5 with a fresh head tends to be in the mid 150's. If you have the right builder a .5mm over b25 with everything trued up, balanced, weight matched etc can make upper 160's in spec e30 trim.