4 replies to this topic

[Roger Clark]

David Beard and I were looking at some FPFs recently and we noticed differences in the way the spark plugs were positioned in the cylinder head. All had apparent provision for a second plug, but in some cases the plugs were positioned so that the engine looked like a 2-cylinder, twin plug while in others they were more separated. If you consider the notional twin plugs being numbered 1 - 8, some engines had the plugs in positions 2, 3, 6 and 7, others had them in 1, 3, 5 and 7. David may have some photographs which illustrate this better.

I know that in 1959 Climax introduced a Mark 2 version of the FPF which had changed positions of the inlet ports and different orientation of the plugs as a result. I also know that most of the engines we were looking at were probably not built by Climax at all. I don't know whether either of these things explain the differences.

[Dick Willis]

My Mark 2 has them 2,3,6,7.

[David Beard]

Two snaps to show the different plug positions Roger was describing...

[David McKinney]

Perhaps Tony Mantle has his own way of doing things

[T54]

My three Climax and a spare short-stroke 2-liter head all have the plugs like in the second picture, and they are all original, not new heads. I assume that the first pic is from an early 1.5 with non cross-bolted crank main caps.