m44/m42 spec rally engine

[sh123]

hi,

Looking for some guidence. I have a e36 compact with an m44 in. ( I did put a thread up in another section of this forum but had no reply, so figured a lot more people come on this section)

My car is used for rallying and nothing else so street driveabilty isnt a factor tbh. but one thing i do need which for some reason other people who run compacts in rallying stuggle with is setting off the line due to the type i do there is a lot of stop start.

ive found that my car is hugely under powered and sticking a better air filter and exhaust wont give me the power i need.

Ive come up with some sort of spec but im not 100% sure what best etc

I firstly considered 2.1 but have been in touch with an engine builder in the uk and told me not to bother. He claimed he could get 220 out of a m44 with standard inlet (which my regulations say has to stay standard)

so I was thinking of putting high compression pistons that vac offer is 12:1, vac say race gas only but im assuming i could get away without special fuel. as most competitors i run against dont and they have more modified engines than i will have?

What rods do people recommend?

Will standard m44 crank be allright? or what do people suggest?

and cams? I was considering cat cams but what lift i am unsure of.

Plans are to assemble it myself but ill send the head away to have work done on it.

Im in early stages of getting info together and doing research so bare with me if i come across as clueless haha

Also plans may change as im waiting for regulations to be updated at the end of the year.

[benz-tech]

You will probably need to spin to 8k, maybe higher, to get that kind of power out of an M44. I'd talk to Mertric Mechanics since they are probably one of the few that have gotten anywhere close to that output. Spinning that high will Definately place more stress on some well designed internals. The crankshaft and valve train aren't among those, though( for real high rpm). I can't confirm this but IF the rod design is the same as the Euro S50 then they are good to at least 7,500 rpm. Delta cams said they didn't like the results of welding cams. A lot of this depends on your budget, class rules, and how competitive you want to be. Also, after having just installed a light flywheel, I noticed one of the benefits is how much smoother it is near redline. Granted both it and the pressure plate are balanced

[Darky]

Hi

There's nothing wrong with the m44 crank for na but as soon as you go forced induction it can't handle the stress of massive power.

The block could get bored out upto 87 mm. Requires a different headgasket though, Athena.
Or 86 mm and stay with m44 gasket.

As for the head m44 is designed for low friction.
M42 for revs.

My 2c

Cheers Rohan

[sh123]

Thanks for the replys!

Yeah I thought the limiter would have to be raised. Ive just remembered about the guy in the forsale section who is selling a m48 lightened and balanced crank with mahle forged pistons and stronger rods. im unsure what the compression ratio was but it brought it up to 2.0ltr. would this be a better option to go down to? atleast then id get a better crank rather than a standard m44 crank. also no modification is needed to the block for this sort of set up.

Darky, are you suggesting i go for m42 head? I had thought this but I wasnt sure if id get any real gains?

budget - i havent really thought about it. my other option would be a honda s2000 engine with type 9 gearbox. Engine and box would be 4000 pounds. but I know i wont get s2000 sort of power out of a m44 so I dont want to spend huge amounts on it.

[Darky]

Hi again

Your from England, you would be crazy not to find a m47d20 crankshaft.
Find a late e36 m42 also and some new s50 Pistons and play mix and match.
M47 crank, M44 conrods, m44 front timing case, m42 head and 86 mm Pistons.

Good to go!

Rohan

[sh123]

Think thats the plan atm but with mahle forged pistons.

Am i going to have reliability issues with block bored to take 87mm pistons and a 12:1 compression ratio?

Cheers
Sion

[benz-tech]

You might want S50 rods in that mix since they are 5mm shorter. I love hybrids.  I have 3 different engines in my build: M44 block and crank, M42 head, S50 pistons. My personal record was a datsun I built some years ago with 4 different engines to make a 2.3L monster.

[Darky]

Benz tech which Datsun motor did you play with? Sr fj l.

87 mm fine with Na but there is no more room between bores, go 86.5 safer!
For forced induction they generally only go to 86 mm.

12:1 is qiute high. Depends on the quality of rings and Pistons and how you look after it.

Cheers Rohan

[Natcho]

S50 rods dont work with m42/4/7 crank, the diameter of s50 rod are bigger

[benz-tech]

S50 rods dont work with m42/4/7 crank, the diameter of s50 rod are bigger

real oem  has the big ends both at 45mm for an S50 and an M42. The set I had a while back definitely looked identical to my stock M44 rods minus  the 5mm overall length.

[Darky]

S50 rods dont work with m42/4/7 crank, the diameter of s50 rod are bigger

Correct for Euro s50

[Natcho]

Off course i was talking about euro s50, didnt know for US s50

[sh123]

Right current plan atm is

S50 euro pistons
M44 rods
M47 crank
Going in a m44 block with custom headgasket and trying to find a late e36 m42 head.

an engine builder from croatio is supplying the lightened and balance crank along with pistons. And says i can run my standard m44 rods. What happens with the pin can i use standard pins?

im still unsure what cams to use probably catcams but i need to find the best balance as id like some decent torque. Any suggestions?  Also im unsure what to do about head, get it worked on now or not :/

Cheers
sion

[sh123]

Can a standard m42 head be made to take 6mm valve stems? And 35mm valves ? Does same apply for m44? How much gains will i actually get from going to m42 head?

What is everybody doing with the harmonic dampener with their high revving engines?

Cheers
Sion

[Darky]

Hi

A late model m42 head comes with 6 mm stem valves.
So you can change them, just order 16 m52 guides and valves, most people think all m42s are 7 mm stem and get confused!

You could put 35 mm valves but not common at all because the valve seats would have to be changed.
So typical max is 34 mm on inlet.

Gains from the m42 head would be measured by being at 7000 rpm and blowing up.

Vac under drive pulley set.

Hope this helps
Rohan