Author Topic: BIG NEWS! Ask DON DUNCAN your M42 questions (Read 14881 times)

Febi Guibo · « **on:** March 28, 2006, 08:14:40 AM »

note:

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

----

Hi all:

BIG NEWS!

I am pleased (and quite frankly, a little surprised) that Don Duncan, the proprietor of GT Technic 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):

Quote

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 · « **Reply #1 on:** March 28, 2006, 08:27:31 AM »

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 · « **Reply #2 on:** March 28, 2006, 08:31:19 AM »

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 · « **Reply #3 on:** March 28, 2006, 12:16:12 PM »

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 · « **Reply #4 on:** March 28, 2006, 12:20:08 PM »

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

Febi Guibo · « **Reply #5 on:** March 28, 2006, 12:40:26 PM »

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

tim_s · « **Reply #6 on:** March 28, 2006, 12:42:33 PM »

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 · « **Reply #7 on:** March 28, 2006, 12:49:33 PM »

Quote from: 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:)

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 · « **Reply #8 on:** March 28, 2006, 01:00:55 PM »

Quote from: Febi Guibo

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 · « **Reply #9 on:** March 28, 2006, 01:53:09 PM »

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 · « **Reply #10 on:** March 28, 2006, 02:00:04 PM »

Quote from: Febi Guibo

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

dude8383 · « **Reply #11 on:** March 28, 2006, 02:08:44 PM »

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

i dont even know what to ask..

Febi Guibo · « **Reply #12 on:** March 29, 2006, 11:56:43 AM »

BUMP!

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

so GET THOSE QUESTIONS IN!

thanks all!

kowalski · « **Reply #13 on:** March 29, 2006, 12:14:20 PM »

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

nickmpower · « **Reply #14 on:** March 29, 2006, 12:16:33 PM »

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