M50 NV head to M52 block issues!

[Manuts]

I put together an engine with a m52 block (which had a cracked head) and a NV M50 head to later put into a e30. (I was told this would work) The valves, trays, lifter, etc are from the NV head. The cams are from the M52 head. I was told the cams would bolt onto the NV head with no problems. However i did a compression test and the results are lower than when the cracked head was on. It seems its losing pressure on the exhaust camshaft. Do the trays and lifter also have to be swapped out with the m52 cams? The m52 cams fit on the NV m50 trays but i had to grind down the tray for the exhaust as the cam was rubbing on the tray. Do i need m52 trays to go along with the m52 cams? Any help would be appreciated. thanks

[jahnaboi]

Yes. You need m52 trays with the m52 cams. Cams and trays are not interchangeable unless its within the same generation. (obd1 with obd1 - m50/s50 obd2 with obd2 - m52/s52).

[Manuts]

Thanks for the reply. Do i also need the m52 lifters along with the trays and cams? Also would i be able to put vanos m50 cams without vanos trays and lifters, ie use NV lifters and trays with m50 vanos cams? Also as i understand it NV m50 cams cannot be used in m52 block correct? So my options would be:


M52 cams and trays (Lifter?)
M50 cams (trays and lifter?)
NV m50 cams not an option!

TIA

[jahnaboi]

Yes. m52 cams + trays + lifters.

[Manuts]

Thanks jahnaboi, alternatively there is a local guy who is selling M50 vanos cams which i understand has more aggressive profile than m52. Would i be able to bolt those cams onto my NV trays and lifter or do i need the vanos lifter and trays? BTW where in CA are you, just wondering. thanks

[jahnaboi]

I believe the m50 vanos cam's are a direct drop in on a non vanos head. Located in Porter Ranch, CA.

[Manuts]

Cool, not to far from me. I will just get some M50 vanos cams and put them in as I dont have the lifter for the m52 cams. Non vanos cams will not work correct? Different profile i assume???

[416stroker]

What harnes are you running and dme?

[Manuts]

The engine is in a wrecked 328i right now. I am trying to make it run before it take it out.

[416stroker]

ok id do m50 or s50 cams in the non vanos head and convert it to vanos and you should be good to go.

[Uber E30]

Cams and trays are not interchangeable unless its within the same generation. (obd1 with obd1 - m50/s50 obd2 with obd2 - m52/s52).

Actually this quite isnt true. s50, m52, and s52 all have the same trays. m50's are the only ones that have different trays.

Also m52 cams/trays can NOT go into a NV head, nor can m3 cams like suggested above. You also cant convert a NV head to work with vanos...

[evil_twin]

Whats the point of doing an NV block with a vanos head?

[mentaleeill]

Actually this quite isnt true. s50, m52, and s52 all have the same trays. m50's are the only ones that have different trays.

Also m52 cams/trays can NOT go into a NV head, nor can m3 cams like suggested above. You also cant convert a NV head to work with vanos...

i ran s50 cams in my vanos m50 head with the m50 trays. and why cant you convert a non vanos head to vanos? the front front cover unbolts and the vanos bolts right on.

[416stroker]

Actually this quite isnt true. s50, m52, and s52 all have the same trays. m50's are the only ones that have different trays.

Also m52 cams/trays can NOT go into a NV head, nor can m3 cams like suggested above. You also cant convert a NV head to work with vanos...

Where did you hear this? You are wrong. The heads are all the same p/n and the s50 trays are the same as a non vanos. You can convert a non vanos to a vanos.

[Uber E30]

No, they really arent, and you can verify this in real OEM.

325IS head and a 95 m3 head




Not to mention the hundreds of posts that say you cant put m3 cams in a NV, you can only hotcam with another NV cam.