Long Cam followers

[lyons]

I notice that some of the "usuals" will supply LONG cam followers inplace of the normal SHORT ones.

These measure 27.11 mm instead of 21.20mm

Assuming that the diameter is the same as the original Jaguar part, is it OK to use these long items without any adverse affects on the engine.

[christopher storey]

Hmmm. I cannot for the life of me think what long followers would be for, unless it was to stop the buckets rocking in the tappet bore , which is usually the result of the tappets having gone barrel shaped in the first place . I would also worry about the clearance at the bottom of the tappet on full lift

[mgcjag]

Hi Lyons.....I had tappet noise when i first got my S2 4.2 and on inspection the followers had gone slight barrel shaped, fitted the longer ones with no problems......also know a few others who have done the same...Regards Steve

[james-t]

Hi Lyons, like steve ,i have used the slightly longer followers without problem. i got mine from watjag but had to use thicker shims all round as the thickness of the follower is thinner than the standard.James

[abowie]

We routinely use the long cam followers on all head rebuilds. The ones we use are also 20 thou bigger in diameter. These obviously need to have the seats recut to suit but this makes for a beautifully quiet head. The extra length decreases rocking of the follower when it is contacted by the cam lobe and hopefully decreases wear and barrelling of the follower.
IIRC the cam followers on the original XK heads were longer. The "short" ones were from the XJ6.

[mgcjag]

Hi Lyons....just to comfirm....the longer followere that i used were from SNG....and they were a direct replacement with no need to machine the head.....after i replaced them and re shimmed the engine runs really quiet......Steve

[paulsco]

My experience is that the long cam followers were the norm for early engines including the E Type, but ceased being made for a while and the only source of supply was the later short ones, which were supposedly more desirable because they were lighter.

I found they were thicker and I couldn't get a reasonable clearance without having the the valves machined and are no doubt more prone to rocking.

It was only later that the long cam followers were re-introduced.

If I was doing it again I would definitely go for the longer cam followers.

Paul