Cams - different types of cam gear bearing?

[jammy_basturd]

Currently fitting the new (second hand) cams I got a few weeks ago, and have just noticed that the new cams have a flat, broad bearing, whereas my existing cams have a bearing with a step in it. Pictures explain it far better than I can.

Existing:



New:


Anyone know why they are different? The best conclusion I can come up with is that my existing ones are 4.2 (obviously) and the ones I've bought are 4.5? Though Racing Green only list one pair of cams for AJPs?

[itiejim]

My car was originally a 4.2 but was rebuilt as a 4.5. I have no receipts for cams and therefore assume that I have the original (early) 4.2 cams which do not have the step in them.

Hope that helps!

[jammy_basturd]

What year/month was your car? Mine is Feb '97.

I've fitted one already. You can see a mark on the bearing of the new cam, well the gear slots on up to the start of that mark. Technically I see no reason why it should stop the engine working as is. However I just want to make sure that at least the profiles are so radically different (4.2 compared to 4.5 for instance) that it could require a remap or something.

Edited by jammy_basturd on Sunday 16th August 11:25

[Allandwf]

Weren't the early 4.2 profiles slightly different ? I'm sure I read that somewhere.

[jammy_basturd]

Apparently there are about 5 or 6 different cam profiles, and I think 3 or 4 different versions of the 'clatter' cams.

[itiejim]

Mine's June '96.

[ridds]

Wonder if that change was after a few had the ends of the camshafts snap off?

[jammy_basturd]

Just spoke to Dom @ Power. He's never heard of the cam gear bearing having a step in it (a la my original cams). He suggested that it might be a {lesser designed} piece by a company like Autocraft. Apparently all the cams should be as per the broad flat bearing, and that the cam gear only covering half the bearing is normal.