deck height

E28 technical advice asked and given! Troubleshooting, modifications and more.
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Devinder
Posts: 810
Joined: Feb 12, 2006 12:00 PM
Location: Berkeley, CA

Post by Devinder »

Does anyone have access to BMW or machine shop data to confirm that the M30 and S38 deck heights are both 217.5 mm? I'm getting ready to order custom pistons and rods and so I'm double checking all of my measurements.

Devinder
Bert-Ola
Posts: 170
Joined: Feb 12, 2006 12:00 PM
Location: Karlskrona/ Sweden
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Post by Bert-Ola »

I've always thought the deck height on all M10/M30/M90/M88/S38 are 218,0 mm.

Would be good to have the confirmed deck height.


[Edit by Bert-Ola on [TIME]1140551069[/TIME]]
Madhungarian
Posts: 716
Joined: Feb 12, 2006 12:00 PM
Location: San Jose CA

Post by Madhungarian »

Check and double check sooo you do not end up like this %)

Image

It worked out OK! Engine management still has a proglem with it...Say what?????
Devinder
Posts: 810
Joined: Feb 12, 2006 12:00 PM
Location: Berkeley, CA

Post by Devinder »

Bert-Ola,

This is what I thought too but I have reason to suspect that it is actually 217.5 mm. I first noticed the problem when I measured the compression height on my M30b32 pistons. The CH is 39.8 mm and they stick out just above the deck. So, I measured the deck height on this block and it's 217.5 mm. I thought maybe it had been decked so I also measured my 3.0CS engine and it's 217.5. My spare S38 block is also 217.5.

Devinder

-----
I've always thought the deck height on all M10/M30/M90/M88/S38 are 218,0 mm.
Would be good to have the confirmed deck height.
Bert-Ola
Posts: 170
Joined: Feb 12, 2006 12:00 PM
Location: Karlskrona/ Sweden
Contact:

Post by Bert-Ola »

Devinder,

I'm willing to give you right on this!

Today I measured my M30B35 which are standing without head in my garage.
Piston height should be 39,85 mm according to Mahle parts catalogue.
Rod length 135 mm.
Crank 86 mm.
At TDC the piston on #1 cylinder stick out about 0,3 mm, and #6 about 0,4 mm.

This makes:
39,85+135+(86/2)=217,85
217,85-0,35=217,5 (which would give Devinder right)
Devinder
Posts: 810
Joined: Feb 12, 2006 12:00 PM
Location: Berkeley, CA

Post by Devinder »

Thank you -- I feel better with some else getting the same measurement.

Time to order custom pistons for my S38
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