Hi, I need some help please. I’m looking for a replacement cylinder head for my Mark 5, which I am given to understand differs from the Mark 4, in spite of them both being big valve heads. Are the correct part numbers GU28022160 and GU28022278 and were these heads used on other models like the 1000s, or are these different again with different part numbers? It is proving quite difficult to find what I seek, so if anyone has a pair of Mark 5 heads they want to sell I’d be interested. Also, are the 47mm and 40mm valves on the big valve heads all the same or are the specs different depending on the model? Thanks.
[quote=“PeteLMV, post:1, topic:21721”]
GU28022160
If you look on the Fowlers website, it suggests that the 1000S uses the same heads, although it gives various options for LeMans V cylinder heads withe 3 different part numbers for each side.
What is wrong with your heads? Could they not be re-engineered.
Hi Pete
From what i can figure out 28022160 is the correct R/H Cylinder Head for a LM1000. The 28022278 cylinder Head is listed for a LM1000 but also for the 1000S Series 1. The basic difference as noted in the Parts list is 2160 has a natural finish were as 2278 has a grey painted finish. Iassume both your Heads have the same finish?
Some more info from you would be helpful so us nerds can be more accurate!
Regards, Nik
The left hand head has five fins cracked off, probably dropped by a previous owner; I don’t have the broken off bits for a weld repair and I think the cost of making new fin sections and welding them in place would make it unviable costwise. The head itself works OK but looks awful. The R/H one has only one fin broken out, probably by someone who didn’t know what they were doing and this one might be worth taking to an expert cast aluminium welder to be fixed. I didn’t realise Fowlers carried MG spares, I must have a look on their site. Thanks for your response.
Thanks Nik, yes, same aluminium finish. It kind of makes sense the 1000S would use the same heads as that model came after the CI? I was reading around online to see if different models use the same heads, but then came across some information that there are machining differences on the Mark V as the pistons are more domed, but surely this would be the same on the Mark IV?
