Hi all who here has put the bigger 47mm e34 b35 standard valves into a m90 or early m30 l jet head? Or is there bigger then that?
Was thinking with this m90 to-
-Do big headwork
- turn the tunnel manifold into a itb set up wich will make the itbs pull from the original side.
Bigger valves.
And a 328° cam
I can get b35 valves easy and i already have the other m90 head bought and the itbs which are from a s38 with conversion to m30 are practicaly mine which just leaves the cam
Putting in b35 valves into a m90
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bpoliakoff
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Re: Putting in b35 valves into a m90
The head will be very prone to cracking due to the water passages being very close to the combustion chambers. You need a newer head and that will cause a lessening of compression. Better off with a good port job or doing the engine right and tearing it down and then building it correctly. HP is not cheap nor easy. My M90 retains a reworked M90 head, new high compression, 10:1 pistons, porting of the head and manifolds, a 284 cam and oversize throttle body. Had I known what I know now, I would have gone to a B35 head and had the pistons made accordingly. A cam as big as you are saying will cause a good amount of power loss as it is way to much for the concept you are stating.
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
flickr.com/photos/bertsphotos.
Re: Putting in b35 valves into a m90
bpoliakoff wrote:The head will be very prone to cracking due to the water passages being very close to the combustion chambers. You need a newer head and that will cause a lessening of compression. Better off with a good port job or doing the engine right and tearing it down and then building it correctly. HP is not cheap nor easy. My M90 retains a reworked M90 head, new high compression, 10:1 pistons, porting of the head and manifolds, a 284 cam and oversize throttle body. Had I known what I know now, I would have gone to a B35 head and had the pistons made accordingly. A cam as big as you are saying will cause a good amount of power loss as it is way to much for the concept you are stating.
Oh ok so i would be defeating the purpose basicaly yea? And is it poosible to make the b35 head run l jet? So i dont need to convert