replacement heads

[Baikal Bimmer]

Hi everyone,
engine went off to the shop the other day and news came came back that the head was cracked, and that it was likely not repairable. After searching the forum regarding "heads" and such, I have learned that later model heads are preferable to originals, but not all later heads work with all pistons or fuel systems. My car is a 1972 euro csi that is getting larger forged aluminium pistons so that further complicates things. Any advice on what head I need, or what changes to the engine are required, is greatly appreciated.

 

[sfdon]

Look for the later head with updated coolant passages with early intake ports and no fuel pump hole.

 

[Stevehose]

message sent

 

[Honolulu]

I don't think the (normally) small increase in piston diameter will have any effect on choice of later cylinder head. The fuel pump pushrod hole can be covered by a plate that is either home-made, or ordered from a supplier (admit I have not ordered such a plate myself but have seen them, similar to a 2002 engine).

 

[Baikal Bimmer]

What about the distributor? I heard that some modifications or adapter must be used

 

[pat cooks]

you have to fit an adapter nut to run a distributor from a later motronic cam but nothing on the head, the basic issue with fitting different heads is making sure that the grand piano shape on top of your pistons will clear the shape of the head, I have in the past, in desperation, removed some metal from head combustion chambers using a sharp small cold chisel, needs must etc. send some pictures of the head cracked area, I do know the best head welder in the west, well east, he is in Latvia, Juris Ramba, Ramoto LTD, the courier was here today dropping off the bottom half of a very rare 1930 V4 OHC motorcycle engine that he has resurected for me, from a Matchless silver hawk..... he tests all heads hot using steam before and after welding, also some pictures of the piston tops would be useful, I may have a head...........

 

[Baikal Bimmer]

you have to fit an adapter nut to run a distributor from a later motronic cam but nothing on the head, the basic issue with fitting different heads is making sure that the grand piano shape on top of your pistons will clear the shape of the head, I have in the past, in desperation, removed some metal from head combustion chambers using a sharp small cold chisel, needs must etc. send some pictures of the head cracked area, I do know the best head welder in the west, well east, he is in Latvia, Juris Ramba, Ramoto LTD, the courier was here today dropping off the bottom half of a very rare 1930 V4 OHC motorcycle engine that he has resurected for me, from a Matchless silver hawk..... he tests all heads hot using steam before and after welding, also some pictures of the piston tops would be useful, I may have a head...........

you have to fit an adapter nut to run a distributor from a later motronic cam but nothing on the head, the basic issue with fitting different heads is making sure that the grand piano shape on top of your pistons will clear the shape of the head, I have in the past, in desperation, removed some metal from head combustion chambers using a sharp small cold chisel, needs must etc. send some pictures of the head cracked area, I do know the best head welder in the west, well east, he is in Latvia, Juris Ramba, Ramoto LTD, the courier was here today dropping off the bottom half of a very rare 1930 V4 OHC motorcycle engine that he has resurected for me, from a Matchless silver hawk..... he tests all heads hot using steam before and after welding, also some pictures of the piston tops would be useful, I may have a head...........

First, thanks for the input everyone. Secondly, the head is basically unrepairable and I am not going to be using the piano pistons. They will be swapped with larger forged aluminum ones. Nearby there are a few early 80’s bimmers for sale. So, I was thinking that if I get one of those, I can get a head and a five speed tranny. What do you all think of that?

 

[pat cooks]

with flat top pistons you can use almost any M30 head with the early inlet ports, later ports were much larger and do not mate with the E9 manifold, ideally you want a 5 speed with a speedo drive, some early1982-83 E23,E28 and E24 cars had the casting machined for a speedo drive but it was not installed as they had an electronic speedo, you can retrofit the drive and gear from a 4 speed, just make sure the casting is machined with a blanking plug fitted, if you don't find a good head yours may be repairable by the right man, but an unmolested head is always a better option, remember the head must have the front cover fitted when it is skimmed, and your front cover may not fit straight onto another head if one has been skimmed and the other has not!

 

[adawil2002]

Look for a 1983-1986 head. This was the first order of business when I bought Athena in 2011. When you locate a newer head don’t forget to have the front timing chain cover milled with the head.

We used a thicker head gasket to keep compression the same.