Yes Straight through ,NO Restriction
ET: Engine (Twin) Cams
- Thread starter rapide049
- Start date
Perhaps it is the way the cams have been "timed" when the engines were assembled? If one engine was assembled by someone using the 4Deg BTDC technique, that engine will likely perform well. If the other were assembled by relying on the dots on the cams, it could well have one, or both, cams a tooth advanced or retarded or any other random combination of valve opening & closing times.
To identify the differences between the engines I would suggest you start with compression pressures, which can be difficult enough with a kick starter, but just looking at the piston crowns through the plug hole may be enough to give you a hint? Then compare valve timings between the engines with a degree wheel.
The audible noise from a timing chest has nothing to do with "quietening" ramps, in spite of what is written in the factory publications. If there is a reduction in audible sound between cams with quietening ramps & those without, that is coincidental. Quietening ramps are about letting the valve settle onto its seat gently, 'decelerating" it if you like, to reduce shock loading, wear and seat recession, any reduction in sound that our ears can detect is secondary.
If you have a noisy timing chest, it is not necessarily confirmation of MK I cams, there are plenty of other possible explanations for that.
To identify the differences between the engines I would suggest you start with compression pressures, which can be difficult enough with a kick starter, but just looking at the piston crowns through the plug hole may be enough to give you a hint? Then compare valve timings between the engines with a degree wheel.
The audible noise from a timing chest has nothing to do with "quietening" ramps, in spite of what is written in the factory publications. If there is a reduction in audible sound between cams with quietening ramps & those without, that is coincidental. Quietening ramps are about letting the valve settle onto its seat gently, 'decelerating" it if you like, to reduce shock loading, wear and seat recession, any reduction in sound that our ears can detect is secondary.
If you have a noisy timing chest, it is not necessarily confirmation of MK I cams, there are plenty of other possible explanations for that.
A quick way to check the valve timing is just see if the valves are rocking , The same height
at TDC, looking down the plug hole.
at TDC, looking down the plug hole.