Hi . I seem to be missing a few of the cooling fins around the spark plug hole on the cylinder head on my M20. Has anyone got a photo of this area so that I can make some fins up and mig them on. Thanks Jeff

email (option): m90disco@fsmail.net

Hi Jeff, missing one as you can see, hope it helps,

Good luck, Michiel

Jeff, this shows the one that is missing in Michiels photos but has others missing.

Between the two you have a full picture.

email (option): rays54@hotmail.com

Hmmm.... Has anyone noticed the difference in fin design between Michiel's head and Ray's head? Have a look at fin number 7 counting from the bottom of the photos.

email (option): spacemonkeym@gmail.com

There are some variations in fin patterns on the iron heads...Bear in mind that there were two different castings for the two combustion chamber layouts used on '10 bolt' heads. Also there were variations in heads with the same combustion chamber layout. These may have come about as the patterns were replaced periodically over time...Each pattern will only do so many castings and there were probably multiple patterns made by different pattern makers with the production numbers and time scales involved...BSA may also have used more than one foundry at different times...
The Alloy head is also a completely different casting...
Detail differences can also be found in crankcases, barrels and other castings if you study a lot of them...Ian

email (option): ian@wright52.plus.com

Many Thanks for the photo's , I will be getting the MIG welder out this afternoon.
Jeff

email (option): m90disco@fsmail.net