Interchangeable parts?

[msp13]

I am completely new to bmw's so don't flame too hard if this question has been asked or if it is a dumb question. Just post up a link to a plethora of knowledge...

Anyway, I have found that alot of people are doing motor swaps which is all good but after searching for about an hour I couldn't find anything about "frankenstein" motors.

I have been a honda boy all my life so things like Ls/Vtec are very popular (which is taking the ls block and bolting a vtec head onto it). The benefits are you keep the ls block which has more displacement and replace the crappy flowing ls head with a super high flowing vtec (hondas vanos) head so you have a little torqueier motor. All, well the vast majority, of B series honda motor parts are interchangeable.

From what I have read it seems that the downfall of the m20 is the fact that has a terrible flowing head...how could it not be with 2 valve per cylinder sohc setup. Is there anyway to bolt up a dohc 24 valve head onto an m20 block? Are the bolt patterns the same and all or what? Not that I am going to do this per say but I just want to know if it is possible and if anyone has experience with it.

[george graves]

Is there anyway to bolt up a dohc 24 valve head onto an m20 block? Are the bolt patterns the same and all or what? Not that I am going to do this per say but I just want to know if it is possible and if anyone has experience with it.

BMW's don't work that way. Get a complete motor, and try and learn the search feature a bit better. All the info you need is on this site.

[msp13]

So if you say its not possible...then I would assume that there probably isn't any write ups about it.

If that is the case, using a SEARCH feature in an attempt to find something that doesn't exist...might be kind of impossible.

I did attempt to search for a little over an hour. Me not finding anything is explained by there not being anything to find.

[george graves]

Search is your friend. Use it.

/thread

[msp13]

/toolbag.

[Anthrax]

The only viable 24 valve-option would be to do a complete m50-swap, or any of the other 24 valve engines. It´s been done to death, and info is found in this subforum : http://www.r3vlimited.com/board/forumdisplay.php?f=129

There was rumors and pictures of a 24 valve cylnder head for the m20 available from Racing dynamics, but no one has ever been able to find one.

[george graves]

/toolbag.

Says the guy with 9 posts. I was being helpful. EAD.

[george graves]

/toolbag.

:loco:

[msp13]

I found plenty of m50 swap stuff. The main question wasn't mainly about a different head on an m20 block...it was mainly a pointless question of interchangability of any and all parts.

Just in my experience, a motor of a family series has parts that can be swapped with parts from a different type of motor from the same series.

honda d, k, b, series are all interchangable within their family.
alot of nissan motors are the same.

With so many engines under the mXX designation, I figured it would be a long shot but I thought I would go ahead and ask.

[Jesse30]

the only bmw 6's i know of that are interchangable are m50,m52,s50,s52.

there arent any 24v head swaps for an m20.




your basically limited to FI on your m20 if you wanna make 340. other than that, you need to do a swap.

[msp13]

You are right.

The number of posts I have is a definate indication of your attitude.

the only bmw 6's i know of that are interchangable are m50,m52,s50,s52.

Thanks.
Thats all I was asking...I guess just next time I shouldn't try to give any examples of what I am talking about.
My general question was about any type of combination motor.
Honda has lsvtec
Subies do sti block and wrx head
etc.

The only bmw I have found has been changing the head on the eta motors. Is that the only one the bimmer guys do?

[Charlie]

etc.

The only bmw I have found has been changing the head on the eta motors. Is that the only one the bimmer guys do?

Yes.

Just buy a 24 valve motor and start your project from there. It'll save you a lot of heartache.

-Charlie

[DaveSmed]

honda d, k, b, series are all interchangable within their family.
alot of nissan motors are the same.

With so many engines under the mXX designation, I figured it would be a long shot but I thought I would go ahead and ask.

OK Ill be the nice guy for the moment. Parts within engine families ARE interchangeable. Engines with an M in front of them (M10, M20, M42, M50, M60, M70, etc) are non-motorsport engines (for the most part... there are some exceptions like the M88) and engines with an S in front of them (S14, S38, S42, S50, S52, S54, S62, S70, S85, etc.) are motorsport engines.

You have to research into what engines are part of what families, like the M20 and M21. The M20 and M50 are NOT part of the same family.


Your trying to put a H series head on a D series. Not gonna work.

Next time, try to make it less obvious you came from a Honda background, and don't piss off respected members of the forum, ESPECIALLY george graves (and no, I won't elaborate further. You can search, or keep it up and find out on your own soon enough.)

[nando]

the heads aren't interchangeable, but things like rods and cranks are.

also, (and I may be ridiculed for posting this here) technically the M20B25 head an excellent 2 valve design, surpassed only by air cooled porsches and the huge ports of the LS1. It just happens that the 24v heads from BMW are even better.

Throw in a nice cam and it can certainly flow well.. the problem is you miss out on the flat torque curve of the VANOS motors.

[george graves]

and don't piss off respected members of the forum, ESPECIALLY george graves (and no, I won't elaborate further.)

((I LOL'ed. All he needs to do is search for "goat fucker"))

msp13, As a noob, you rubbed me the wrong way, but it seems you know a few things about motors - so - welcome!!!

(and I may be ridiculed for posting this here) technically the M20B25 head an excellent 2 valve design, surpassed only by air cooled porsches

I'm with you Nando. Stock, a m20 puts out 160 HP for for ~2.5 L. Not bad at all. Then again - it's all about TQ, The "bar" for a motorsports NA motor is 100 hp per liter. But as light as an e30 is - it's not needed.