A 24-valve M20

[fporro]

My conversation with RD about 24V heads were brief but I'll enquire further while placing 2nd group buy of headers.

I'm not the most technical e30 guy, so how about you guys making a list so I can inquire about those things instead.

Was told "they needed further development at about 250K"
As far as price, I just divided 250K by 100 units, (75 = $3333 and 50 = 5000 ea)

Aloha :)

[LJ851]

Agree 100% with digger.


I'd rather see an aluminum M20 block than something that bmw effectively already designed and produced in large quantities.

[jeffnhiscars]

My read of this is....$250k for "R&D" does not include the cost to produce 100 heads but gets you production ready.

[digger]

and oem dual valve pistons, instead of e36 units ?

you'd probably want 4 valve cutouts on the pistons lol

I would definitely be down. $2,500 isn't even that bad of a price, hell a Stage 3 M20 head from VAC is $2,599. I doubt you'd find 99 other people to jump in, AND go through with it though.

you'd hope it didn't turn out like the recent RD headers which are nowhere near as good as the originals.....

It still uses the stock intake and exhaust by looks of it (id hope not) which may introduce constraints that limit the port layout effectiveness compared to more modern designs. if it doesnt then its no chance in hell of it being 2500 otherwise where do i pay?

I’d say the biggest impediment to power on the m20 is the intake manifold, IMO you’ll find the intakes limits before you reach that of the head once you add a little cam into it and massage it with a die grinder. There isn’t much you can do to the stock intake to improve it either except throw it in the bin. So youd need to do this with the 24V version to

Then the fact that you'd have difficulty getting different cam profiles, it wouldn't have any vanos system, it’s a 1980’s 4V design so its probably going to be inferior to more modern engines.

[stonea]

I'll like to add that during passed conversations Federico said that "250K for further development before 100% completion was needed".

That's a 100 of us at $2500 ea.

Perhaps value assessed from original expected sales figures.

In any event, the meltdown was real, from heads casting molds to valve covers and rigs for headers, everything.
RD's unequal passion and love for motoring can bring them back, all they need is a commitment from the community and maybe ...
a good 3d printer ;)

Mahalo.

Aloha.

I would definitely be down. $2,500 isn't even that bad of a price, hell a Stage 3 M20 head from VAC is $2,599. I doubt you'd find 99 other people to jump in, AND go through with it though.

[fporro]

and oem dual valve pistons, instead of e36 units ?

[digger]

From Frank's discussions with Federico @ RD

"It is the same head that Johnson made, it was sold to Callaway in CT then it passed on to RD., by then BMW had their new engine, so project was dropped."

Not sure when RD got it/gave up on it

Reeves Callaway developed and marketed a 4-valve M20 head back in the E21 323 days
Discussions started - November of 1983.
Initial blueprints made spring of 84
Hans Hermann would perform the initial design.
Six months later,the initial design was finished.
On October 1, 1984,at 2:27 am, the first Quadros 2.3L prototype on the dyno at Callaway Turbosystems
By the end of 1984, the people at Callaway had customized a special intake design, coupled with the Hartge exhaust, and achieved 200 HP.
In car testing - winter of 1984

On looking for timelines I stumbled across this, lots of people talk about doing it but hadn't seen or heard on this one

3.0 Liter Stroker M20 with s50b32 Head


Published on Feb 25, 2014

iirc there is also a m54b30 head on an m20 block.

TBH i cant figure out why you would build a 3L m20 and put a 24V S50B32 head on it. it seems like a complicated and potentially unreliable way to achieve something that basically exists already. at least use a 75mm stroke if youre going to do it

[fporro]

I'll like to add that during passed conversations Federico said that "250K for further development before 100% completion was needed".

That's a 100 of us at $2500 ea.

Perhaps value assessed from original expected sales figures.

In any event, the meltdown was real, from heads casting molds to valve covers and rigs for headers, everything.
RD's unequal passion and love for motoring can bring them back, all they need is a commitment from the community and maybe ...
a good 3d printer ;)

Mahalo.

Aloha.

[whodwho]

back from the dead...


It's always been my understanding that the release of the e30 m3 killed off the 24v m20 heads

From Frank's discussions with Federico @ RD

"It is the same head that Johnson made, it was sold to Callaway in CT then it passed on to RD., by then BMW had their new engine, so project was dropped."

Not sure when RD got it/gave up on it

Reeves Callaway developed and marketed a 4-valve M20 head back in the E21 323 days
Discussions started - November of 1983.
Initial blueprints made spring of 84
Hans Hermann would perform the initial design.
Six months later,the initial design was finished.
On October 1, 1984,at 2:27 am, the first Quadros 2.3L prototype on the dyno at Callaway Turbosystems
By the end of 1984, the people at Callaway had customized a special intake design, coupled with the Hartge exhaust, and achieved 200 HP.
In car testing - winter of 1984

On looking for timelines I stumbled across this, lots of people talk about doing it but hadn't seen or heard on this one

3.0 Liter Stroker M20 with s50b32 Head


Published on Feb 25, 2014

M20b25 engine block with S50b32 (E36M3) cylinder head .. Protest Safe DMSB group H15 engine
Nearly 1,000 hours of working time for planning and implementation .. Over 2 years.
But for now I've got a unique engine ...
It was supported by a forged crankshaft with 86mm stroke and connecting rods H ...
Schmiekolben according to my specifications ..
dry sump pump ...
Freiprogramirbarem KMS controller ....
airbox ...
2Scheiben AP sintered metal clutch Nought Nothing was left out.
What can I say about the performance ....
SUFFICIENT .:-))))
Comments about this is, please save any M20 block and look closely!

[ELVA164]

back from the dead...


It's always been my understanding that the release of the e30 m3 killed off the 24v m20 heads

That seems like a reasonable conclusion, since the 2.5 with a 3.73 was already torquey enough to beat an M3 to 60 unless it had a 4.10 rear.

[Julien]

back from the dead...


It's always been my understanding that the release of the e30 m3 killed off the 24v m20 heads

[TobyB]

You aren't referring to the Schnitzer 4 valve M10 heads are you?

oh, yeah. probably am, now that you say it.

t

[nando]

BMW made a 24v M20. Its called the M50.

[lukeADE335i]

There was a BMW production prototype for a 4v head for the M10 in the early 70's.
BMW decided that it would be too expensive and too hard to maintain (i.e. warranty).

Rumour has it that BMW also originally wanted to stick with a single cam for the M50, but went over to 24 valves for marketing purposes to avoid being seen as technically inferior to Mercedes (and by then the Japanese were also getting into twin cam engines in their mainstream vehicles in a big way).

[LJ851]

Alpina did a 4 valve head for the M10, too, and Alpina and BMW got along pretty well.

I have never seen an Alpina 4 valve M10 head, You aren't referring to the Schnitzer 4 valve M10 heads are you? I have seen a few of those in person.