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Engine swap

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Grapedude
Posts: 11
Joined: Thu Jul 26, 2018 6:47 am
Location: Blenheim NZ

Engine swap

Post by Grapedude » Wed May 22, 2019 5:42 am

Given the difficulty in tracking down M90 engine components and the large amount of M30B34/35 parts available does the later block have the same mounting points in the engine bay? Ignoring electrical and ancileries does the motor physically just slot onto the crossmember engine mounts?
thanks
Hamish

bpoliakoff
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Re: Engine swap

Post by bpoliakoff » Fri May 24, 2019 1:51 am

Grape what M90 parts are you having a hard time tracking down? The only really different parts are the pistons. Bearings, rods are the same as well as injectors fuel pumps etc. Computer is different and that's it I have one and haven't had a problem finding parts. When I had it rebuilt I had custom pistons made all else was available. It's basically a B34 with a larger bore and higher compression pistons.
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.

G03rt2
Posts: 60
Joined: Sun Nov 05, 2017 11:48 am
Location: Wisconsin

Re: Engine swap

Post by G03rt2 » Sat May 25, 2019 2:21 am

I would reference the firstfives.org technical archive for swapping advice on this subject. It doesn't bolt right up, but at the same time, it's also not that hard.

Grapedude
Posts: 11
Joined: Thu Jul 26, 2018 6:47 am
Location: Blenheim NZ

Re: Engine swap

Post by Grapedude » Mon May 27, 2019 5:46 am

I'm having trouble finding any off the shelf oversize pistons for a block that needs a bore hone. Also having trouble finding a headgasket... tho I'm trying to get a vulcan cut-ring from SCEGaskets.... i have tried to get in contact with them via their website but no reply as yet..anyone else tried these?

bpoliakoff
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Re: Engine swap

Post by bpoliakoff » Wed May 29, 2019 3:26 am

As I said, I had forged pistons made to size by JE pistons in the states ran me about $800 with rings and wrist pins Ross pistons in the states makes a high quality product as well. I am going to send you a pm for a contact for Josh Parsons in Sydney. He will be able to give you many contacts for parts as he has just had several race prepped motors built and is a great guy to know.
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.

DrTwincam
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Joined: Mon Apr 29, 2019 3:58 pm
Location: GA, Jawjuh - California

Re: Engine swap

Post by DrTwincam » Sun Jun 02, 2019 12:33 am

You can also reach https://uempistons.com/ regarding Keith Black Pistons. They are Hypereutectic. Not forged however an excellent product for far less money than a Ross, Wiseco, or JE. We used all of them in racing at various points and there were distinct benefits to the Hyper's over forged. One was a much tighter Piston to cylinder wall clearance which helps with oil retension. The Je's and most other forged pistons are going to ask for a 2.5-4/1000's of an inch clearance. The Hyper's run as tight as 1/1000. The US forged are also noisy until the warm up. All you would need is your desired bore, or nearest slightly larger, as well as pin height w diameter and ring stack. Have the weight in grams available as well. They just may have something off the shelf. I know Toyota has some engines in the 93mm bore sizes that may be close. UEM is an excellent source for mix and match parts. We did bore a B35 US Block to a 94mm bore that used a 94mm VW piston. I believe they were german Cima's. It was a flat top that was very near 10:1 w a standard m30 rod. The VW pin specs were identical to that of the BMW. That engine lived a long time in various cars. On another note, those same vw pistons were also available in a dish top, ie turbo application. The cost was about 1/3-1/2 of JE's back then. All the big players make an off the shelf 94mm VW Piston.
2012 X5M
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Grapedude
Posts: 11
Joined: Thu Jul 26, 2018 6:47 am
Location: Blenheim NZ

Re: Engine swap

Post by Grapedude » Tue Jun 04, 2019 11:44 pm

I like the sound of 'off the shelf' pistons...any idea of part numbers or engine that uses them? Again, thanks for the help, its been super!

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