Cam timing

[cinquecento]

In the middle of changing cams, old one is out and starting the installation of my V8D stealth cam tomorrow.

Can I please grab some feedback on the following:

1. Just removed my TVR435RM 116 marked cam from my 96 serp 500 to find up to 1mm difference across some of the cam lobes. Is this a large amount?. Mathematically it is over 10%.. but I am unsure of the performance effect.

2. When checking the cam timing for the 435, I found it was opening at 33 deg before TDC and closing 50 deg after BDC. The opening time seems OK but it seems to be closing too early when compared to the Piper cams Rover V8 spec sheet where the earliest any of their cams closes is 67 deg after BDC.

Any ideas?..

[Del 203]

Only one person to ask mate


I think i have is mobile nr

[Pupp]

If you're installing a different cam, does it matter provided the valve train is specced/clearanced for whatever the new cam needs (I know a song about this)?

I have also measured minor differences from lobe to lobe on new cams and big differences in base circle dia from one cam to another (hence the comment above...

[spend]

What lift are the figures you quoted?

[GreenV8S]

cinquecento said:

1. Just removed my TVR435RM 116 marked cam from my 96 serp 500 to find up to 1mm difference across some of the cam lobes. Is this a large amount?.

If you mean the height of the lobes differs by up to 1mm, that indicates that some of the lobes are badly worn. The hardened surface is extremely thin, and once that's gone the base material will wear relatively quickly so you were probably well on your way towards a round cam.