Barksavon
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| posted on 19/1/11 at 08:40 PM |
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Another Camshaft Question
Further to my recent post re camshaft timing......I'm still fiddling with my Newman cam (Fast Road) on Pinto engine. The data sheet shows valve
lift to be .379 inch on both inlet and exhaust, ive checked total valve lift on in and ex valves on 2 of the cylinders (with a dti on the spring
retainer cap) and it appears to vary between .425 to .445 inch which is 0.040 - 0.060 above what i think it should be.......is this difference ok??
As you may gather this is the first time ive fitted an after market camshaft and tried to accurately set the timing so any advice would be
appreciated
Thanks
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will121
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| posted on 19/1/11 at 09:08 PM |
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would think the quoted cam lift would be as measured on the actual cam lobe, what you are measuring on the actual valve is the cam lift multiplied by
the ratio of the cam follow'er (if that makes sence)
if you are timing in the cam what you are generally looking for to start with is the centre of the maximum cam lift
[Edited on 19/1/11 by will121]
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snapper
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| posted on 19/1/11 at 09:12 PM |
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I would suspect that the smaller figure is cam lift i.e the difference between the base circle and the lobe tip.
Pinto has a ratio built in to the rockers that increases the lift at the valve.
You have 9.62mm at the cam, 11mm at the valve if you achieve 0.445
[Edited on 19/1/11 by snapper]
[Edited on 19/1/11 by snapper]
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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mcerd1
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| posted on 19/1/11 at 09:25 PM |
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^^ what they said
If your looking for max. lift you just need to find it from both sides (ie. turning clockwise and turning anti-clockwise) then take the middle of
these 2 as the max. lift (much the same as finding the true TDC)
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Barksavon
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| posted on 19/1/11 at 10:09 PM |
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great stuff, didnt realise it was so technical but its good stuff to learn...thanks a lot
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