View Single Post
Old 10-22-2020, 05:57 PM   #5
Senior Member
Brian's Avatar
Join Date: May 2010
Location: Masterton, New Zealand
Posts: 2,924
Default Re: Finally some Cam Degree Numbers - Now what?

I think Jack is right, ie, they measure from base circle...
however, going by your numbers you have;
ex opens 59.58 BBDC
ex closes 9* ATDC
This gives a duration of 248.5* as opposed to their stated 260*
Looks like your opening is close, however the closing is too early.
The closing events are more important than the, if you retard the cam by the one tooth as I suggested earlier, the new figures will be;
open 51.5* BBDC
closes 17* ATDC
duration obviously remains the same @ 248.5*
Furthermore, by doing this the distributor timing will be knocked back 16* and will be near where it should be.
My opinion....
I would have checked both inlet and exhaust timing events during the initial assembly
Unfortunately, two half wits don't make a whole wit!
Brian is offline   Reply With Quote