Not a swap but M30 specialists needed

[///Mayhew]

So I am looking into buying a e34 Alpina B10 3.5(i know its not a e30 :(, but still a sweet car) with a cracked cylinder head. Now my question is can i use any head from a M30B3?, or does it have to be the 3.5 head, or even worse does it have to be a Alpina head?

I havent found any information saying that Alpina did any reworking to that head but please educate me.

Thanks

[euroshark]

If its a B35 bottom end, especially an Alpina bottom end, you are most likely going to need a B35 head due to compression differences between the B34 and B35. Alpina did do head work according to the books I have, but you probably would not lose a significant amount of power by running a stock head with the Alpina cam.

Keep us posted!!

[///Mayhew]

Ok thanks, Next question how can i tell the difference between the b34 and b35?

[euroshark]

I'm not 100% sure how to identify the head and block as being B35, but the guys over at www.myE28.com might be able to help you out as many of them have upgraded to B35 engines or B35 heads for their turbo B34s.

[SpunkyE30nOk]

i always thought the alpina b10 m30 was heavily massaged by alpina. i don't think it'll be so easy just swapping heads....maybe you can find a e23 745i *they are very rare but it can be found* its based more off the M88 motor but it may be closer to an alpina head than a reg N/A m30

[euroshark]

Spunky, the B10 3.5 is not the same as the B10 BiTurbo, it's a slightly worked over B35 with approximately 260hp. It received pistons, headers, ECU modification, and some mild porting in the head. A B35 head will work, but to ensure that you aren't losing performance you may have the machine shop try to duplicate the work that was done on the original head.

[E30/M30]

A B35 head will work, but to ensure that you aren't losing performance you may have the machine shop try to duplicate the work that was done on the original head.

Yep you need to replicate the head squish area to match the raised pistons or the engine wont turn over. It won't be too bad a job as you've got the old head to copy from.

I bought a B10 bottom end but i never had the B10 head to copy from so i had to grind out my head squish area which was very time consuming.

This is part way through, you can see the fresh metal where i've been grinding, more had to come off and a smidge from the other side of the chamber.



You will also have to get the chambers CC measured to ensure they are all with in 1 CC/ML.

If you arn't going to port the head you will probobly be best off using a standard inlet manifold or you might have mis-matched ports.

[Funkmasta]

It is pretty easy to tell the difference between the b35 head and the other M30 heads...

There is a water jacket that comes out the *rear* of the head on all M30s except the b35, where it comes out the side (@ the rear)

I have a spare b35 head if you need one...
-J

[Belteshazzar]

Alright, next question;
what's the difference between b35 and b34 bottom ends?

[Funkmasta]

There are a few differences...

The pistons are different
Rods are the same
crank is the same

b35 picks signal up from the flywheel, b34 and lower pick up the signal from the flywheel

Most b35s have different locations for the motor mounts than b34s. The exception is the 88-89 b35 out of the E24, which has the b34 mounting locations

[Belteshazzar]

huh.

thanks.

"pistons are different"
compression?
any particularly interesting combinations(like when I mixed 325i parts with my '88 SuperETA)?

[Funkmasta]

the mix and match I am not sure of...
The b34 pistons are of a lower compression breed...

[///Mayhew]

Well guys this dream may not come true, they put it up for auction so now i have to fight everyone to get this thing and its a closed aution so you dont know what others have bid. Another bad thing is i cant take a closer look at it, just from the outside :hitler: What do you think this car is worth?

[Belteshazzar]

so, the m10 and m30 are related in some ways. They, ah, don't happen to have the same bellhousing bolt pattern or anything ;)

[euroshark]

They do in fact, or so I have heard... There was a guy on E30tech who used a Getrag 240 from an M10 on a 335i that he built. Makes sense really...