M44 upgrades

[MoMansi]

Hi all,

i'm new here, i have an E30 coupe with M52B28 engine, i will be swapping it for an M42 or M44, didn't decide yet, however I'm leaning towards the M44 for the smoothness and refinement, the car is a daily driver, no tracks or auto cross for now, i previously drove an S14B20 which was an excellent engine, got two in the garage right now for rebuilding, but that will take some time, so i decided to go for the 4 cylinder engines again, the M52 is fine, but i like high revving 4 cylinders better.

i got some questions, will be starting with each one at a time,

does the M44 benefit from the 57mm second butterfly upgrade like the M42???

[benz-tech]

An M44 may benefit from the larger tb but it's mostly unproven. It would be dead last on my list of mods and even then, only if I fell into one for cheap. The stock m44 cams are so sleepy that I'd doubt it would do anything unless other major work is done. Sorry for the late reply, we're normally pretty helpful.

[MoMansi]

so what do you suggest?
i've been reading a lot on this forum, and i'm learning a lot on the way, i can't stroke the engine for two reasons:
1- i can't supply the diesel crank here, it will cost hell A LOT.
2- we don't have decent tuners here that one can rely on so far.

so i was thinking, M42 with:
1- higher compression ration, 11:1
2- i can get the S52 lifters and tray and custom fit the tray for a lighter valve train along with 6mm valves
3- i already have a bored TB, secondary ported to 57mm
4- was thinking of porting the shorter runners on the DISA plenum for higher rpm gains.
5- chip the DME from a reputable tuner.

opinions please?

[benz-tech]

If you haven't already, curl up with m42club.com on your device next to a nice warm fire and start reading. Several of us there have done different types of builds with varying results.  The M44 is no B18 so don't expect a catalog with inexpensive bolt-ons.

[Darky]

Use a e30 m42 inlet manifold or m50 manifold cut down or itbs. Late m42 and m44 inlet manifolds have disa and although good for bottom end it restricts the car later, 4 even length inlet runners is the way to go!

[benz-tech]

m50 manifold cut down

I never even thought of this. But I might need to look into it. It meets one of my main criteria,  it would be cheap.

[sh123]

m50 manifold cut down

I never even thought of this. But I might need to look into it. It meets one of my main criteria,  it would be cheap.

I had thought of this for mine but im not 100% if i could to pass rally regulations. Would be interesting though.

[MoMansi]

maybe the problem with the DISA valve is on the short runners, maybe they need porting, has anyone tried that?

[MoMansi]

Doesn't the M43 has a version with plastic intake manifold with DISA?
looks almost identical to the M42/M44, but the two runners on the DISA look a bit larger than the M42/M44 one...

any ideas?

[MoMansi]

here it is

[MoMansi]

i just remembered something, i used to have a 4G92 Mivec engine, it's a 1.6 later engine producing 170HP with Mivec, and it has a similar roller / rocker valve train setup to the M44 but has a conventional intake system, the engine revs to 7500 rpm from the factory...

is there a difference in the valve mechanism prohibiting reaching that rpm? if the bottleneck is not in the mechanism, then it should be in the cams or the intake ports themselves, i.e; head porting....

[MoMansi]

here is a picture of the head of the Mitsu

[benz-tech]

maybe the problem with the DISA valve is on the short runners, maybe they need porting, has anyone tried that?

They could use pocket port-matching. Around 1mm radius iirc to the gasket size. I started on mine but I decided to use the e30 manifold since he e36 port angles are not the same for all cylinders.  In my opinion the air has too far to go  far in this manifold. What do I know, tho.

[wazzu70]

The M44 head is similar to the mitsu heads it seems. I have noticed it is similar to the 4G63 heads on the EVO. These heads can handle really high RPM which makes me think the M44 is not a bad design. I think the main thing holding it back are the weak cams it comes with. I would love to see how some aggressive cams perform! I also think the BMW rockers seem quite heavy, so this would need to be improved as well for higher RPM use.

Honestly I think the M42 head gets used the most because its the easiest to get with more aggressive cams.

[Darky]

Hi

With cutting down the m50 manifold, if you where really clever you could open the plenium up and add little trumpets. Would possibly work better than itbs, you see no butterfly in the way. Throttle butterfly before plenium.

You would have to check bolt compatibility, or be good with a welder. Compare there gaskets.

Just a thought

Cheers Rohan