02GF74
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| posted on 27/3/07 at 12:41 PM |
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identifying a cam?
I am curious as to what cam I have in my 1300 crossflow - if I took the rocker cover off and using a dial guage measuredthe lift, that would go so way
to identifying whether it is standard or not?
I have twin 40s and can set the idel to be as low as 600-800 whcih is relatively smooth - am I right in thinking something like a BCF2 or 3 need to
have much higher idel speedS?
(only other way would be to reomve the timing cover and look for any ID stamped on it - not so conveneint),
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Kissy
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| posted on 27/3/07 at 01:20 PM |
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Add a degree wheel to your crank and then measure the number of degrees the inlet and outlet lobes lift the rocker for (start of lift to end of lift)
and you've got the duration. This should be enough combined with the max lift measurement to ident the cam (take into account a bit of wear if
there is any evident - shorter duration, reduced lift). If it's a cam made from a blank it may have some rings or dots cast in it as i.d. HTH.
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Kissy
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| posted on 27/3/07 at 05:19 PM |
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...sorry, didn't read your last sentence.
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mark chandler
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| posted on 27/3/07 at 07:24 PM |
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Dial gauge on the rockers will tell you all you need.
Two turns engine is 1 turn cam, so using the gauge determine the centre of the lobe, 10 thou each side of lift, centre then mark the front pully. Wind
the engine over until the cam stops moving the rocker properly (you have an opening and closing ramp, which means that the cam lowers the valve but
does not slam it into the seat) so you are looking for it to stop dropping significantly, mark the pulley then using a bit of maths calculate the
duration in degrees.
Other thing is just measure the lift, see if its what you expect on the pushrod end.
Look for things such as double or tripple valve springs, this may indicate fiddling.
Regards Mark
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