91 318is GT car

[pmachan]

Killer!! It makes power all the way to 7.5 limit and im guessing a bit beyond; what rpm are the cams set to drop off at?

.... really tempting to have done for a gts2; reverse swap from m3 6 cyl to 4cyl like the Supra mk4 in JGTC



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Not sure how competitive the light car/small motor thing is in NASA GTS. If you can start out front and keep the higher power cars behind initially until you get through a few corners, great, if not, its a hard go.
The power cars out drag you, then park in the corner, VERY hard to pass, especially if they make it difficult.
Hot setup in GTS3 I believe is an e36 m3 with an S54, detuned, the TQ characteristics are very good vs a built s52.
I have no idea if our car was competitive in GTS2 with the old MM motor.

The cams peak around 7400-7500, start dropping after that the way its tuned currently, red shift lights go off at 7600 I think, with rev limit at 7800.

[Wanganstyle]

Wet sump yes.
Yeah, when we were shopping the build around, Dave showed me some other M42's he had done, very impressive.

I'll attach a dyno sheet from ours, its just a random run, made 255 this run, IIRC, best run was 266hp, 198tq.
I have a lot of the runs on video.

Killer!! It makes power all the way to 7.5 limit and im guessing a bit beyond; what rpm are the cams set to drop off at?

.... really tempting to have done for a gts2; reverse swap from m3 6 cyl to 4cyl like the Supra mk4 in JGTC



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[pmachan]

Wet sump yes.
Yeah, when we were shopping the build around, Dave showed me some other M42's he had done, very impressive.

I'll attach a dyno sheet from ours, its just a random run, made 255 this run, IIRC, best run was 266hp, 198tq.
I have a lot of the runs on video.

[Wanganstyle]

How good is the head? This really is key.

As I said, our motor is not out of the ordinary as far as output per cu in for a racing engine.
2hp per cubic inch is not uncommon.

Rebello is originally famous for datsun inline 6; my local machine shop owner has known him for 30+ years


I wonder what the street potential of m42 at rebello would be; there was some really hot m42 development in the bay area the last decade.

Is the engine running a wet sump still?

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[djjerme]

For how light they have that car, 500/700 probably works really well. For something heavier (2650) you may want to get a bit more in the front and rear if you are running coilovers. For a track only car, I would suggest 650-750 in front and 800-1000 in the rear. The heavier rear spring if you decide to run without the rear sway. Of course, this is all dependent on what you are trying to accomplish and the class rules you run in. Obviously, there are SE30 cars that run quick with their non-coilover suspension..

[pmachan]

How good is the head? This really is key.

As I said, our motor is not out of the ordinary as far as output per cu in for a racing engine.
2hp per cubic inch is not uncommon.

[Emre]

270hp at 10.5 compression is insane for an M42.

Especially considering the 7.5k rev limit. Seems hard to believe you can get so much power from such a small engine with such low compression at such low rpms.

The engine we're building for my 16v vintage racer is a 2.3L twin-cam (Cosworth "Coscast" head) with 10.5 compression and a 7.5K rev limit. We have custom cams being built by Hasselgren Engineering, a genuine DTM manifold, and a twin-Weber DCOE 48 setup designed and tuned by a winning Formula Atlantic engineer. If I break 240, I would be very pleased.

Guys with a similar build as mine starting with a 2.5L engine and 11:1 compression are making about 270 reliable HP. If Rebello can match that output with just 2.0L on 91 octane, then they must really know their stuff!

[pmachan]

The blow up vid is the MM motor, connecting rod broke just below the wrist pin, completely destroyed the entire motor, the rest of the rod kept slicing its way through everything in its path, block, pan, subframe, starter, nothing was salvaged.

The spring rates work well in this car. I'd like to someday change the rear geometry, get the DTM kit or something similar, as it does struggle mid-corner-off on the power, especially in a bumpy corner.
Does doesn't put power down like an e36+ chassis.

Yes Rebello makes power, he makes some pretty sick numbers out of a true 1.8L GT3 motor as well, more than what we have, but thats big compression, race gas etc.
But in all honesty, our motor makes about what it should, pretty standard power/cu in in the race engine world.
Probably be in the 300hp range at 12:1 on race fuel.

[FredK]

Wow. Rebello sure knows how to extract power. 270hp at 10.5 compression is insane for an M42.

[JRKOUPE]

Just watched a few more of the vids.......

do u like those sprg rates?.....they are what Im installing on a 2650 pound car...are they stiff enough for you?...

Im driving to events still.....

what was the blow up?.....trans?....in the blow up vid...

[pmachan]

Not sure how much lighter than an s52 this engine is, but I suspect a lot.

The Metric Mechanic engine was in the car for a couple years I think, we blew it up the first year we had the car, however, we were revving it too high, unknowningly.

This engine has maybe 10 hours on it, if that. Plus, we had to re-bearing it almost right away after an off track punched a hole in the oil pan...
I am not sure how long we will run it, the goal was to not have to touch it for 2-3 seasons, hence the low rpm we run it at (7500 max).
I have dyno sheets, I'll post one later, when I am on my home computer.

It has custom JE pistons and custom Carillo rods. ITB's are TWM/Borla. The motor runs on 91, but we run a small amount of Torco additive to be safe.

Brakes are no issue, ever, spring rates are 500f, 700r, with Bilstein race dampers from Turner.

[word is bond]

How long have you been running it in its current iteration? Has it been much more reliable than the Metric Mechanic engine, despite the major power? Pistons/rods? ITB setup looks really cool. What throttle bodies do you start with?

[Nsquared97]

Love everything about this, awesome work!

[Wanganstyle]

The motor was built to be a full racing engine, so it has extensive headwork, custom cams, and was tuned for a couple days on the dyno, by a builder well known for making power.
I will say it was not cheap, we could have gone to an S52 or something for MUCH less money, but we wanted to stick with the lightweight theme of the car.

The engine that came in the car was a Metric Mechanic 2.1 Rally M42, it made about 160 at the wheels from what I recall, it was fairly strong in the car, but it exploded in grand fashion.

When I say basic car, I mean the rest of it, suspension is stock e30, no geometry mods, just bolt on stuff you can get anywhere, even has non-adjustable dampers..
Stock 318 brakes, with PFC01 pads, the diff is not stock, but again, bolt on type deal.

Wow awesome.

Rebello is close to me; was considering a built 3.3L street S54 but the weight package and aggressive high rpm attack of a 4 cylinder engine has always allured me (rx7's and sti's is the background)

What is the service interval of a M42 built like that by rebello?

you can run 91 pump gas on it?? Do you happen to have a dyno sheet? I'm sure I can ask them for one if you cant dig it up.

[Jean]

I am not a fan of the stock m42, but what you had done to yours is awesome! Great job! Post more pictures! :p