Which engine would you choose for a swap?

[djjerme]

Metric Mechanic 2100 Rally

I don't trust anything MM posts for hp. I have yet to see a MM engine actually put down on a dyno what they claim. Know of two local guys that are still bitter about their MM motors actual numbers.

So long story short - M54.

[digger]

I don't trust anything MM posts for hp. I have yet to see a MM engine actually put down on a dyno what they claim. Know of two local guys that are still bitter about their MM motors actual numbers.

truth spoken

[nando]

Yeah, I don't have an MM engine, but I built mine with their parts - it's been reliable, but the HP claims are BS.

[varg]

I don't trust anything MM posts for hp. I have yet to see a MM engine actually put down on a dyno what they claim.

I don't know anyone who has a Metric Mechanic engine but it usually seems that engine builders can't stop crowing about dyno results and proudly display their SAE gross engine dyno plots and MM refuses to publish anything but numbers.

[djjerme]

Which of these 3 engines would you choose for a swap? M54, M42/M44 stroker, or S14

Yup. It’s a little old school mentality when everyone “knew” that camel hump fuelie heads were worth 30+ horsepower. Back when people would walk around claiming 300hp but put it on a dyno and you’re lucky if you threw down 150.

Somewhere I have the dyno results of the MM 2.5 Rally S14 here in PDX.


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[MrBurgundy]

expand on this, i'm curious to hear it

[Caperix]

This months issue of grassroots motorsports they do a track comparison of a 318is they rebuilt using a metric mechanic stroker engine & a stock e30 m3. The m3 was a few seconds a lap faster around vir and all the testers preferred the m3 even on the street.

[nando]

That's because a $10k MM built M42 realistically puts down less WHP than a stock M20B25. :(

[varg]

Interesting, I was looking forward to seeing the results after reading how they wanted to beat the M3. The odds looked to be in the M3's favor because the 318is build was just so damn mild. They seem to have highly overestimated that 2L stroker engine, which is rated at "170hp" on the MM site, and not gone far enough with the suspension, the Eibach springs are pillow soft if this is correct. Assuming the same tires between the cars, 170hp and mild suspension just isn't enough to beat an M3. Still down on power, it would need a huge grip and braking advantage to win. Or they could've just avoided the milquetoast M42.

[digger]

MM make some great parts and the quality seems to be very good in that they generally use quality materials, processes with good machining etc, but their engine combinations simply just dont work anywhere near as well as they could. far too much emphasis on smooth idle and emissions and they are a dog as a result poor specific hp and specific torque on the dyno. the recipe for top performing engine hasn't changed in the last 70+ years, its actually not difficult at all.

A NA M42 just needs some cubes, compression, proper head/induction work, tuned headers, proper cams and tuning. choose the parts that work together to be more than just the sum of the individual parts (its always about the combination of parts not how much $$$ are spent)

The MM headwork and cam specs leave alot to be desired and its the same on all their m20, m30 etc and since almost all the power is in the induction side and cam if that's wrong the whole engine under performs

[word is bond]

Did they put on proper tires for the head-to-head? It looks like they shelled out for BBS RG-Fs (at $500/wheel), but then put on Vredestein Sport-trac5s? Which looks like a pretty cheap and mediocre tire. A lot of really strange choices for that GRM build...

[Caperix]

Both cars were on Bridgestone direzza dz102 according to the article. The engine put down 143 hp and 130 lb ft on the Dyno.

[varg]

The engine put down 143 hp and 130 lb ft on the Dyno.

They certainly aren't overdelivering on that 170bhp claim then. Definitely not enough to deliver on Classic Motorsports' hope of "embarrassing" the M3.

I'm kinda disappointed, because I have no doubts after following the articles that for what they spent on modding that car you could easily build a streetable E30 that will outpace an E30 M3 on the track. If you go through what they published, $500 on springs and swaybars, $560 on konis, $400 on a diff, $419 on camber plates, $400 on powerflex bushings, $115 on short shifter, $110 on SS brake lines, ??? on steering rack, $2,020 on wheels, $7,500 for the engine. It all sounds pretty par for the course until you get to that $7,500 for 170hp and $2,020 on wheels part. Switch those out for $800 on some RPF1s and whatever an M52B28 with bolt ons and S52 cams costs and you've got that M3 by the short hairs for a hell of a lot less.

Off topic, I know. The whole MM being bad for $/hp is beat to death by now in this thread.

[Codym42]

Interesting, I was looking forward to seeing the results after reading how they wanted to beat the M3. The odds looked to be in the M3's favor because the 318is build was just so damn mild. They seem to have highly overestimated that 2L stroker engine, which is rated at "170hp" on the MM site, and not gone far enough with the suspension, the Eibach springs are pillow soft if this is correct. Assuming the same tires between the cars, 170hp and mild suspension just isn't enough to beat an M3. Still down on power, it would need a huge grip and braking advantage to win. Or they could've just avoided the milquetoast M42.

I totally agree with them not having done enough with the suspension. I read that last article and was disappointed that they went with Eibach springs. I've read countless posts on here about how Eibach springs on e30s are terrible and way too soft. It seems like Grassroots did their homework on the rest of the build but, I think they would have been better off doing at least a spec e30 suspension (Bilstein and H&Rs) or even a proper coilover kit.

[Andrew325is]

I listed the MM engine as an example since it’s well-known. If you don’t like their engines then build your own (or find a different builder). I’m sure you could make an M4x stroker that’s comparable to a stock S14 and it would cost less too.