M52 dissenter, wanting to build a budget screamer

[gooly]

Hi everyone,

I've had my fair share of M50s and M52s in full size E36s and have been craving a smaller revvier car. Dream is an AE86 but bank account disagrees etc. Anyway, I've put my 2.8 saloon up for sale and I'm hoping to pick up a cheap 318ti in px.

My goal is to build a nice little revvy car which is fun to drive. 7.5k limiter, bike carbs, reground cams, straight through exhaust, lightened flywheel; all on a budget.

My current understanding of those mods is this;

Limiter can be mapped in and from what i can see, M42's cam on bucket design can handle it well. M44s are limited to 7.3 or 7.2 because of rocker arm design

Bike carbs can hopefully run off Alpha N ignition from standard ECU with no MAF. ECU runs ignition off of TPS and Crank, carbs handle fuel. Need relevant fuel pump, manifold, linkage and setup plus some decently tuned trumpet lengths. Could be hugely off the mark but I dont see why that wouldnt work?

Standard cams reground by Kent Cams or similar (I'm south east UK based)

Straight through 2" or 2.25" exhaust with resonators etc

I believe the M40 or M43 1.8s had single mass flywheels which can be skimmed and fitted to M42/44s?



Most importantly, I want to do this on a budget and overall huge BHP gains are not something that particularly interest me. As long as it's a responsive, peppy, free revving engine that sounds good I will be happy.

Question is, does anyone see any major flaws or improvements in these plans? I dont plan on changing pistons or crank or anything major like that. A 20BHP gain would in my eyes be phenomenal.

More importantly, as I'm currently in the stages of looking for something to buy, would an M44 or an M42 suit me better? I'm only looking at E36 compact 318tis here. As I understand it M42s have forged cranks and cam on bucket design, and run an older Bosch ECU which must be chip tuned and also does not adapt much to changes, but does have more tuning capability. M44s have bigger displacement, lighter rotating assembly, rocker arms, more advanced ecu but less gains to be had and less free flowing / revving head. By the sounds of it an M42 will be ideal for me; i want an engine which needs to be revved to get the most out of it. Is there anything else I should know? Has anyone here put an M42/4 on bike carbs?

[Darky]

Hi

Sounds like you have the basics, bike carbs have been done but can't remember by who!
Also 2.25 inch exhaust is the standard.

Where are you from?

Cheers Rohan

[DesktopDave]

Sounds like a great idea to me!

I bought a set of R6 FI throttle bodies (38mm?), but never got around to putting it all together. They're inline, separate units and easily spaced out to fit different manifolds. They also have the showerhead-type high impedance injectors. I wanted the CV-type body and they're very cheap & common used. Likely not necessary for a car. The slightly larger R1 (40mm?) units might be perfect.

I've heard that the M40 fly & clutch setup is the same as the single-mass fitted to the early M42 non-A/C cars; we usually swap with an M20 setup over here. Should work just fine either way.

[sh123]

Gooly

not much input but my builder is putting reground cams in my build so will let you know  how they are soon!

they are mild cams though 244 duration and 10.5 lift, but we shall see



Edit. I forgot to write reground cams from kent cams!!

[MoMansi]

the M44 cylinder head is not less revs happy than the M42, the head design is the same as the Mitsubishi EVOs and they handle real high rpm!

what's up with this quote I'm getting to read everywhere, i dealt with high revving mitsubishi EVO and MIVEC engines and they use EXACTLY the same rocker arm / cam layout and design.....those engines used to rev to 7500 - 8000 rpm stock!!