What Engine is best choice for twin cam swap in e30 an m42 or m44?

[beemwr 46]

Before I tell someone it's likely to be an m44, because it has that low torque & about 100cc extra vroom, am l doing a dis-service to an s42 I am anxious to sel to himl. Rather have a happier end result for the person concerned.

The wisdom from members of this forum is being sought.

[Harper 547]

M44 has a larger oil pump that flows better, M42 has the forged crank and supposedly the valvetrain can rev higher. The best version is probably a hybrid of the two.

M44 block with 320d stroker crank and M42 head for the revs and replaceable cam trays. One can dream. 

Edited September 23 by Harper

[Eagle 1662]

Earlier M42 is the easier swap as no modifications needed to fit (in\ex manifolds come to mind). Id say the M44 has more advantages over the M42 if leaving stock, but they are much the same. Finding a good M44 is likely easier.  

[beemwr 46]

16 hours ago, Eagle said:

Earlier M42 is the easier swap as no modifications needed to fit (in\ex manifolds come to mind). Id say the M44 has more advantages over the M42 if leaving stock, but they are much the same. Finding a good M44 is likely easier.  

Do u know anyone who has used an m44 block & put rest of m42 head plus loom ECU?

[beemwr 46]

Yeah, the s42 on dyno could rev to 10,000rpm scary listening at' that,  peak torque 7800rpm.

With standard m44 on carbs 7200 rpm had rev limiter  at 7600. On different dyno.

Low down torque best to have.

[beemwr 46]

On 9/24/2024 at 8:55 AM, Harper said:

M44 has a larger oil pump that flows better, M42 has the forged crank and supposedly the valvetrain can rev higher. The best version is probably a hybrid of the two.

M44 block with 320d stroker crank and M42 head for the revs and replaceable cam trays. One can dream. 

I think the m44, while cast metal crank, doesn't need to be revved beyond 7600 rpm

[beemwr 46]

17 hours ago, Eagle said:

Earlier M42 is the easier swap as no modifications needed to fit (in\ex manifolds come to mind). Id say the M44 has more advantages over the M42 if leaving stock, but they are much the same. Finding a good M44 is likely easier.  

Does cam chain mate up as standard fit, if using m44 with rest of m42 piecces?

[Eagle 1662]

Yes I believe the heads swap. No doubt you need to mix and match various parts to make it work. Don't know anyone personally who's done it.

[beemwr 46]

4 minutes ago, Eagle said:

Yes I believe the heads swap. No doubt you need to mix and match various parts to make it work. Don't know anyone personally who's done it.

Yeah, don't like to be the one to re-invent the wheel. Haven't found any who have done the m44 block m42 head lots of opinions alone doesn't prove it does work though. 

[Harper 547]

49 minutes ago, beemwr said:

Yeah, don't like to be the one to re-invent the wheel. Haven't found any who have done the m44 block m42 head lots of opinions alone doesn't prove it does work though. 

It has definitely been done if you look on the m42 forums. Loads of parts on them are interchangable.

My dad is building a 318is coupe and considered doing a Frankenstein m42/44 but ultimately just went with the m44 for simplicity. Lightweight flywheel, itbs etc.

Edited September 25 by Harper

[beemwr 46]

19 hours ago, Harper said:

It has definitely been done if you look on the m42 forums. Loads of parts on them are interchangable.

My dad is building a 318is coupe and considered doing a Frankenstein m42/44 but ultimately just went with the m44 for simplicity. Lightweight flywheel, itbs etc.

Yeah, If l was clever enough, to have an AI search engine, it would probably get the ideal set-up from m42/44 & other sites devoid of opinion but have the science sorted & save time & money would be the way to go.

If it was just a need for performance  buying the latest & best  performance engine . I'm a period  plus sort.

Your dad's a wise man, in my opinion, & has science to back his choice, dynoes vary, but l had my e30 M3  match similar m44 setup total output. m44 better low down torque. 

[Eagle 1662]

Only gripe with these engines are certain parts being very expensive - timing stuff and sensors mainly. Some of the M42 stuff is NLA too iirc.

[beemwr 46]

7 minutes ago, Eagle said:

Only gripe with these engines are certain parts being very expensive - timing stuff and sensors mainly. Some of the M42 stuff is NLA too iirc.

I have  m42 & m44 engines available & Pelican parts are usually 40% less than BMW dealerships ex Germany,

Also pays to use BMW Europe electolite too, not Austraian stuff.

Thank you for your input, appreciated.

[Harper 547]

2 hours ago, beemwr said:

I have  m42 & m44 engines available & Pelican parts are usually 40% less than BMW dealerships ex Germany,

Also pays to use BMW Europe electolite too, not Austraian stuff.

Thank you for your input, appreciated.

Schmiedmann is almost always the cheapest for genuine parts. And spareto to is better than pelican for basically everything else in my experience.

[Eagle 1662]

8 hours ago, beemwr said:

I have  m42 & m44 engines available & Pelican parts are usually 40% less than BMW dealerships ex Germany,

Also pays to use BMW Europe electolite too, not Austraian stuff.

Thank you for your input, appreciated.

Yeah lots of genuine only bits for anything quality so expensive no matter who supplies it. Local dealer pricing isnt too bad, eg $~400 for a cam shaft sensor, Schmiedmann $350+shipping.