BIG NEWS! Ask DON DUNCAN your M42 questions

[Febi Guibo]

note:

hey, I am going to close this topic for questions tomorrow at midnight EST.

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Hi all:

BIG NEWS!

http://www.gttechnic.com/images/engine.jpg

I am pleased (and quite frankly, a little surprised) that Don Duncan, the proprietor of GT Technic (http://gttechnic.com/) has graciously agreed to answer our questions regarding all things M42-engine related.

Who is Don Duncan?

Don's company prepares SCCA GT2 and GT3 bmw-powered race cars and has done an enormous amount of work developing and building up the M42 for the track. As an excerpt from his web site reads (edited for length):


The GT3 powerplant is a normally aspirated, carbureted BMW 318is M42 engine with a displacement of 1.8 litres. This is the engine configuration that was stroked to 2.0 litres by BMW and was used successfully in the various touring car series throughout Europe during the 90's. Engines are supplied with Carillo or equivalent I beam design alloy connecting rods and custom "touring car" design pistons. The camshafts are computer designed and ground from factory billets. The cam followers are a special solid bucket race component employing shims on the valve stems for adjustment.

The engine uses an externally mounted custom three stage dry sump oil pump with a specially cast dry sump pan. Webber carburetors are fitted to our custom cast intake manifold. Fuel injection has recently been introduced to this class, and we will be using TWM throttle bodies along with our manifolds.


Okay, so how will this Q+A work?

Please post your questions for Don here, I will compile them, edit if absolutely necessary, and forward to him so he can answer at his convenience. When I get his replies, I will post them here.

Please try to avoid duplicate questions, and include your city and country too. Naturally, we wanna represent the uh, massive scope of our global M42 love.

So for anyone who is tired of hearing: "The M42 is a nice little engine, gets great gas mileage... but besides a chip, and an lightweight flywheel... there isn't much you can do blah blah blah" this is a great chance to explore the engine's potential.

OPEN THE FLOODGATES!!

fyi: I am working on some more of these Q+A type things with some other folks... so stay tuned!!

[Zoso]

Nice working getting a professional to agree to answer M42 specific questions!


I think a nice starting point would be to ask his professional opinion about some of the current projects we're talking about such as the MAF conversion and the individual throttle bodies.

[Febi Guibo]

Okay, um, my question...

How high can a street legal M42 reasonably be expected to rev? And what's the deal with the harmonic balancer? --Febi Guibo, NYC

[kowalski]

i know this may be an overgeneralized question, but how does he get an M42 to 260 hp? and if hes willing to share the specs of his engines that'd be awsome... also what would be the streetability of these engines and longevity?

i'm also currious on his thoughts about creating a new harmonic balancer, or if he knows of a better one to use that can handle the higher revs.

his thoughts on megasquirt, good or bad? what does he use?

the lightweight flywheel, is it really that harsh to drop it to 8lbs? or would that be unbareable for a street car?

i think thats it for now, plus i gotta go to school... but i could miss out on this:)

[asubimmer]

dang all the good q's are taken, I'll have to think deeper

[Febi Guibo]

charlie, ask about your turbo project... unless... you don't wanna know the answer... haha!

[tim_s]

cool! nice work! my qs, regarding m42 head

what size inlet valves does he run on the 200+bhp race-car m42s?
how does the m42 inlet tract compare to the euro S50? does he do anything with the seal ring on the valve stem that appears to be a bit of a restriction on flow? how much of the s50b30 inlet can be fitted to the m42 - i'd like to change the m42 lifters, inlet valves and seals/springs etc for s50 items, the most crucial being the lifters and valves. i'm looking to run 200bhp+ on my 2.1 with ITBs and standalone, and am a little concerned about the standard head and esp the inl valves.
Another q i have that's not directly related to m42s, but related to my research into what im going to do with the m42 head, is why the s50 runs smaller valves and smaller inlet tract, but bigger ITB butterflies than the s14.
Thanks!
Tim, Bristol/London, UK

[tim_s]

i know this may be an overgeneralized question, but how does he get an M42 to 260 hp? and if hes willing to share the specs of his engines that'd be awsome... also what would be the streetability of these engines and longevity?

i'm also currious on his thoughts about creating a new harmonic balancer, or if he knows of a better one to use that can handle the higher revs.

his thoughts on megasquirt, good or bad? what does he use?

the lightweight flywheel, is it really that harsh to drop it to 8lbs? or would that be unbareable for a street car?

i think thats it for now, plus i gotta go to school... but i could miss out on this:)

guys to save all the questions on the vib damper (again!), although it would be interesting to have another opinion on this, you can just swap over to the later revised one on which is supposed to be good for much higher revs. sure you'd need to change your other pulleys, but in the grand scheme of things, this is the least of your worries. the only part coupled with rubber is the VR wheel on the standard crank wheel anyway. i believe GTtechnic use custom billet crank pulleys, but they don't run the 60-2 VR wheel so it won't work unless you go standalone or build another wheel.

[asubimmer]

charlie, ask about your turbo project... unless... you don't wanna know the answer... haha!is he going to post here or email him? I'll have to think of a short way to ask him about my turbo project lol

[Febi Guibo]

tim, as expected... you've raised the bar pretty high for us... great questions... I can't wait to see the answers so I know what you're asking!

charlie... I'm going to compile the questions, send to him in a day or so, and then he'll either answer (hopefully) or get a restraining order on all of us... I will post his answers here...

anyway, don't be shy, just fire away!

[asubimmer]

or get a restraining order on all of us...haha thats a good one.

I will think my question through and post it up asap. Thanks for being the middle man :D

[dude8383]

woah i remember you talkin about this sam...this is nuts lol

i dont even know what to ask..

[Febi Guibo]

BUMP!

hey, I am going to close this topic for questions tomorrow at midnight EST.

so GET THOSE QUESTIONS IN!

thanks all!

[kowalski]

ask about the famous tick that most of us have...

[nickmpower]

how worth while is it to replace the standard intake system with ITB's?

[Febi Guibo]

ask about the famous tick that most of us have...

well... we'll see... hopefully mike miller will opt-in and we can hit him with that one too!

[asubimmer]

ohh and how come sometimes we have throtal pulse at idel. I hear they even did it sometimes off the line.

[enildeR]

What happened?

[Eurospec]

What happened?OT, but where about in socal are you from?

[enildeR]

I'm in the OC.

OT, too, but is that a stock rear deck lid? Seems longer than the one on mine. Maybe it's just the way the pic looks.

[asubimmer]

thats a mtech 1 spoiler IIRC, it sure looks like one from that angle

[Gunni]

Q : How advanced can the ignition be on the M42, what is the diffrence between that and stock setup?

Thanks

[Eurospec]

thats a mtech 1 spoiler IIRC, it sure looks like one from that angleCorrect :)

[Febi Guibo]

hey, just an fyi... don got our questions around the 1st of the month, still waiting for a reply... thanks in advance for everybody's patience!

[318isle]

I'll pass by all the technical questions and just go for the juggler. How much would a modded M42 from him cost?
And how streetable are his engines?

Edit: Whoa!!! I just noticed the link, and found my answer...20K!

[kowalski]

i got spend a lot of money here (http://www.gttechnic.com/catalog.html) that intake settup looks interesting, and the cheapest one so far!

[tim_s]

i got spend a lot of money here (http://www.gttechnic.com/catalog.html) that intake settup looks interesting, and the cheapest one so far!

M42 fuel injection intake manifold set (two pieces) $456.00
M42 throttle body set $594.08
Air horns (each) $46.55
i looked at these a while back, you'll need the tbs and the manifold so you're looking at over $1k before air horns, about $1250 with. still a good price though.

worth noting that that lot's not ideal for a road car, the fuel injectors and throttle butterflies are too far away from the valve for a start. also there'd be more costs cos you would have to figure out ICV, brake servo, FPR, intake plenum, tps etc.
think when all's said and done the dbilas setup is the most road-friendly.
the butterflies on that kit look like a good dia. though.

[kowalski]

mmm yes, i didn't really read into the whole thing, i just saw a throttle boddy settup for xxxxx dollars and got excited:)