Considering M42 as my new race engine....need help with questions!

[bmw1602.com]

Hello everybody!

This is my first post here (great forum!), a few of you might be familiar with my project from a few other forums…..It’s been a long time working on it since I have a non-existent budget!
 
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For those interested in the full build
I have a build blog post on bimmerforums…
http://forums.bimmerforums.com/forum/showthread.php?t=935632

Also you can check out my website http://www.bmw1602.com

I also have a build blog (copy of the one of bimmerforums)
http://bmw1602.blogspot.com/

I did finally “finish” the car and vintage raced it a bit in 2007.

I had motor issues and took the car down for a major rebuild. I’m re-doing the suspension, upgrading the roll cage, installing a tilton dual MC pedal setup, new dash wiring etc…..

I was planning on rebuilding a “hotter” m10 race motor……but recently 2 of my good friends started racing with NASA. I helped them build thier e36m3 race cars. The idea of us all going to the same events is growing on me. I really enjoy vintage racing but I think it would be a lot of fun for us all to go to the nasa events together. They will probably be racing in GTS (german touring sedan).

The GTS class is divided into goups based on power to weight GTS1, 2, 3, 4, 5.

At the recent buttonwillow event I have a chance to see “rob_e30” e30 m42 race car.
http://www.m42club.com/forums/showthread.php?t=3463

It was beautiful and fast…..really open my eyes to the m42 potential.

Also a recent 2002 forum member completed a m42 swap
http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,299923/highlight,m42/

which really got my attention!!

So at this point my mind is pretty much made up. With my engine bay looking like this….it’s perfect timing for the swap.





I know from his swap post I need a e30 m42 because of the oil pan location and intake height.

My plan for the engine is N/A power…I think maybe around 160-180hp

1- 8 pound flywheel
2- Aggressive cams
3- Possible intake like the 666 fabrication one ( I will fabricate myself)
4- Maybe Megasquirt
5- exhaust will be pretty open probably side exit (i have no noise restrictions)
6- ?

So my first questions is since I don’t care about emissions and about idle quality is I want to go really aggressive with the cams. Any recommendations or cam specs?

Also what other recommendations do you guys have considering I have no smog or street drivability restrictions?

I’m sure I will have many questions in the coming weeks.

[rob_e30]

Hi, I'm glad you like the car and I'd love to see you and your car at the track.  

Let me start by saying that I'm no pro at this but have gathered some info over the course of our build.  Feel free to disregard as silly anything contained below...

It looks like you're focusing on the head as the best way to get improvements, and you're correct if you're not going FI.  If you plan to run NASA GTS then it's simple power:weight ratio so you don't have a lot of rules to contend with.  If you think you want to run BMW CCA then think about your class.  If I were building an NA M42, in addition to the cams I would upgrade the valve train to solid lifters and lighten the valve train as much as possible to raise the revs.  I'd also go to the M47 crank, custom pistons (or at least S50) and get to about 2.1L (provided there is no displacement limit).  Don't forget a crank scraper, oil cooler, and COP kit (we can help with some of these parts).

I'm to familiar with MS as it does not offer a knock sensor, something I consider mandatory for FI.  With that light a flywheel, it's going to be a challenge in the pits and getting on and off the trailer, but hey it's a race car.  You're going to have to keep the motor high in the rev range all the time.  By lightening the flywheel and shortening the intake you're only going to have power at the high end, so coming out of corners at low revs will lack any "umph".  I would consider something not quiet so light, say 12 lbs or so to help the motor maintain momentum in lower rev corners.


I'd like to talk to you about fabbing an custom intake plenum.  I've looked at your work and think you do a great job.  My fab skills aren't for crap and I don't have a TIG welder in any case.

BTW, Paul and I watched you on Setup.  PM me if you'd like to chat some more or even come down some time to check out the car.

[bmw1602.com]

funny you should reply I was going to PM you, as I figured in the development of your motor you guys learnign a bunch and could give me some great info.

My friend's girlfriend OLGA went for a ride in your car with John when he was driving your car......we did meet that day later when that guy was trying to get a jump for his dead battery from you guys.

IN any case....aren't M47 cranks like impossible to find? and expensive? that's the diesel crank right?

-NO bmw club racing for me. So yeah just GTS so no rules really.....just power to weight.

-Where can I source solid lifters and how much are they? As this motor will live in the high revs for sure and the more revs the better but MONEY is a big factor in my build.

-what you guys using for ECU?

-As far as driving a motor with a small powerband (high rev motor), that's all I do! I raced 125cc gp bikes when I was younger and all my race cars have been "narrow pwerband motors", my current m10 has a narrow powerband and 115hp so it will be nothing new. I'm used to it, just basically got to drive it like a 2-stroke gp bike. It's all about momentum and corner speed! I think it's fun.....! But if I had the money I go turbo....in fact in a year or two that what the car might evolved to.

-I love to work with you guys on a intake! Would be a fun project. Maybe we can barter? You know where I could find a e30 m42? or any of the parts I need? maybe you have some ? Where is you "shop"?

Yes, SETUP was fun and I gained alot of race expirience but it was kinda bullsh*t....topic for another day perhaps....



So.........anyone know where I can find a cheap e30 M42?  If I don't find one soon, I probably just rebuild my m10 and keep this in the backburner....

[rob_e30]

PM me.  I remember Olga and the rest of you guys, but didn't recognize you.  We were focused on packing up there at the end.  We had a brake booster problem that day which has since been fixed.  Regarding an M42, you need to define "cheap" but we recently bought a candidate motor (timing chain jumped a tooth?) and transmission that came with the complete car wrapped around it for $400.

Craigslist is your friend.

[SheldonJace]

Welcome to M42club!

I am actually in the middle of setting up a deal with a guy to trade my current e30 for his e21 with a mildly built m10.

Anyways I have a full spare e30 318is that I wrecked last winter on the passengers side. It still runs pretty well though with a solid idle and starts up every time (with a jump since the battery died). If I don't end up pulling the m42 out of it and building it for one of my cars I'd be willing to sell it for pretty cheap as its just sitting right now and I really don't have time to part it out. The only problem is the car is in Missouri so shipping would be a pain and probably as much as the car would cost you hah. Everything is perfect mechanically on the car though.

I'm guessing you mean Burbank, California right? I drove through Burbank not 2 days ago hah.

Sounds like a great project though so if you end up finding another M42 local and need some parts just let me know.

[maarten1802]

hello i,ve got the m42 in my 1802 to

i drive it every day for 2years now

it runs on lpg

the rev limmiter is gone

it,s realy fast for a stock engine

picture from last sunday on circuit zandvoort in holland

[peerless]

I have built a couple M42s and could offer some advice on uprating alot of little weaknesses on the M42. I learned a few tricks from Teddy Rowe of Metric Mechanic.

I am down in OC. I wouldn't mind be part of the project if your interested. I would be excited and honored to be able to participate in a race car build.

Although I am sure rob_e30 may be able to hook you up all the same?

(I have pictures and references available)

Robert
E30 Motor Werks
714-398-8405