I have both complete m90 and mb30 engines to play around with. The valves and ports on the m90 engine are smaller and narrower than the later mb30 head. I was wondering if I can do a straight swap with the better flowing and larger valves later mb30 head onto the short stroke m90 block. My main questions are maintaining the compression ratio and gasket compatibility ?
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Mb30 head onto an m90 block
- Thread starter sprintevo
- Start date
There may be this possiblity
Love for others to chime in on this if I am incorrect.
Please check if it is a euro L block if so. You can swap the crank from the euro to the m30. So you would have a stroked and larger displacement motor 3.7+. I believe this to be correct but not really sure.
All the best in your build. Hope it comes out the way you desire it.
Love for others to chime in on this if I am incorrect.
Please check if it is a euro L block if so. You can swap the crank from the euro to the m30. So you would have a stroked and larger displacement motor 3.7+. I believe this to be correct but not really sure.
All the best in your build. Hope it comes out the way you desire it.
x_atlas0
Well-Known Member
You are talking about the M30B35, right? (last M30 version, bigger valves, larger combustion chamber,etc)
Love for others to chime in on this if I am incorrect.
Please check if it is a euro L block if so. You can swap the crank from the euro to the m30. So you would have a stroked and larger displacement motor 3.7+. I believe this to be correct but not really sure. All the best in your build. Hope it comes out the way you desire it.
That is backwards. A B34 crank into an M90 block will be a stroker. The M90 is a shorter stroke engine to begin with, with a larger bore than a B34/35. I know if you go to a B35 head you will loose compression as the chambers are larger and will need custom pistons made. I am using J&E 10:1s in my M90. I do believe the B34 head will not cause compression loss. You can always have the head shaved a touch to compensate.
x_atlas0
Well-Known Member
The M90 has the bigger bore, so using a B34/B35 crank will net ~3.65L. Using an E3 3.3Li crank will net ~3.8L, but that is obviously rather tricky to find.
The B35 has larger combustion chambers, so using the original M90 short block will drop the compression.
The B35 has larger combustion chambers, so using the original M90 short block will drop the compression.
Yes it is an M30B35 head in very good order double springs, rebuilt and ported, hence looking to put it to good use. One UK expert has suggested it is a bad idea as the combustion area that overlaps will cause some hot spots and the lands between the pistons are smaller - however I plan to use ARP fastners on studs and possibly a cometic gasket. In terms of pistons I am looking at modern Mercedes diesel flat tops which are more durable and have modern ring systems as a much much cheaper alternative to Mahle or JE custom, they only require a light machining of the little end are to slide the standard M90 rods in place.
My key question about the M90 is if this head swap has been done, if so was it successful? and any tips please
My key question about the M90 is if this head swap has been done, if so was it successful? and any tips please