Cam timing

[Sy#26]

Ok, here are the actual, measured figures on the stock SyTy cam. Cam used had =~ 70k miles on it, well maintained engine. Figures are average of 3 readings, probably +/- 1° or better.

I/O: @ .006" @.050" Max open: @ 108° ATDC = 0.230"
10° BTDC 18° ATDC Duration: @ .006" = 239°

I/C: 49° ABDC 17° ABDC @ .050" = 179°

E/O: 54° BBDC 29° BBDC Max open: @ 71° ABDC = 0.254"
Duration: @ .006" = 253°
E/C: 19° ATDC 15° BTDC @ .050" = 194°

Overlap: @ .006" = 29°
@ .050" = -33°

Thanks to an anonymous donor for a roller lifter to get these figures - all mine are in my new engine.

Jeez, didn't format very well here, did it? Might have to put the proper CR/LFs in it.


Barry - Syclone #26
Bangor, MI

 

[myclone]

Re: Cam timing

Ok, here are the actual, measured figures on the stock SyTy cam. Cam used had =~ 70k miles on it, well maintained engine. Figures are average of 3 readings, probably +/- 1° or better.

I/O: @ .006" @.050" Max open: @ 108° ATDC = 0.230"
10° BTDC 18° ATDC Duration: @ .006" = 239°

I/C: 49° ABDC 17° ABDC @ .050" = 179°

E/O: 54° BBDC 29° BBDC Max open: @ 71° ABDC = 0.254"
Duration: @ .006" = 253°
E/C: 19° ATDC 15° BTDC @ .050" = 194°

Overlap: @ .006" = 29°
@ .050" = -33°

Thanks to an anonymous donor for a roller lifter to get these figures - all mine are in my new engine.

Jeez, didn't format very well here, did it? Might have to put the proper CR/LFs in it.


Barry - Syclone #26
Bangor, MI

Yeeesh, I think the broom handle that I have for a hood prop rod has more lift/duration. :wink: