Advice about cams please

[BI8759]

I'm attempting to rebuild my 1098 engine but my ambition is a lot greater than my skill.

I've just got the cam out. Could anyone tell me what I should be checking for in order to know if it's okay to reuse?

Cheers

[MarkyB]

All the bearing surfaces should be nice and smooth, wear on the lobes is likely to be limited to the tips.
They too should be smooth with no signs of crazing or wear ridges.

[bmcecosse]

Post up pics if you can! And if you have a Vernier caliper - measure the lobes to see if they are all the same height. Inspect the cam followers and dump any that have cracks or crazing on the surface. I expect you'll be fitting a new oil pump anyway...just make sure you get the correct pump.

[BI8759]

Many thanks for the help. I will try and find my camera. The lobes all measure 1.352" +/- 0.002". The bearings and lobes all look okay to me (no crazing or ridges) although the thicker piece that I assume is to balance out the dizzy gear is quite discoloured. I am replacing the cam followers as they are a little bit bashed. I will be replacing the oil pump as it seems a false economy not to. Are there different ones? Now to find that camera...

[bmcecosse]

As long as all the lobes are the same... There are many pumps - you need a short version with the pin drive connection. Just check with the usual suppliers. What else has been done to the engine?

[BI8759]

I don't disbelieve you, Roy, just trying to understand; isn't any difference in lobe size compensated for when you do the tappets? I have put a 12G940 head on it with a HS4 carb. The bottom end looks original so think I will upgrade the timing chain and the oil filter.

[bmcecosse]

The sameness of the lobes confirms the cam is not worn!

[BI8759]

I measured 1.352, 1.353, 1.349, 1.351, 1.352, 1.352, 1.354, 1.351. Is that good or bad or just an indicator of the general condition of the cam?

[bmcecosse]

That's fine - use it!!

[BI8759]

Cool. Many thanks