Timing mark question/problem....

When the piston is up to TDC (zero deck), the pointer is showing around 2* BTDC on the Innovators West damper. The cam was installed 4* advanced on the timing set, I did not degree-in the cam at the time of installation. Start over? Thanks.....glen

I would think you would only be off 1 degree of cam advance/retard since the cam turns half the speed of the crank.

glenevans wrote:When the piston is up to TDC (zero deck), the pointer is showing around 2* BTDC on the Innovators West damper.  The cam was installed 4* advanced on the timing set.....glen

Just treat 2 BTDC as your TDC mark.

supervel45 wrote:I would think you would only be off 1 degree of cam advance/retard since the cam turns half the speed of the crank.

Camshaft phasing does not affect piston TDC.

Sorry, I meant 2* ATDC ( to left of pointer from front), while piston is up to deck.

Get a Moroso timing tape and correct the TDC on your damper.

That is a good idea, thanks. I do have a degree kit now (didn't last fall), should I just start over to make sure the timing dots are correct? Engine has heads on, sitting on my engine stand.

Take the plugs out of the engine and screw a piston stop into #1.

Rotate the engine BY HAND until you feel the piston against the stop. Put a mark on your balancer at the pointer.

Rotate the engine in the opposite direction BY HAND until you feel the stop again. Put a mark on the balancer at the pointer again.

Now measure the distance between the marks. Exactly half that distance (center between the marks) is your true TDC. Zero your timing tape there.

BTW, the reason I stress the "BY HAND" part is because I know a goof who used the starter....very expensive.

Paul Kane wrote:

glenevans wrote:When the piston is up to TDC (zero deck), the pointer is showing around 2* BTDC on the Innovators West damper.  The cam was installed 4* advanced on the timing set.....glen

Just treat 2 BTDC as your TDC mark.

supervel45 wrote:I would think you would only be off 1 degree of cam advance/retard since the cam turns half the speed of the crank.

Camshaft phasing does not affect piston TDC.

Brain fart on my part. I thought he said he degreed the cam and then figured his TDC was off somehow.

Thanks for the help, I will check it out now that it has finally warmed up a bit here.

Simply correct the timing pointer you have or get a different one.

Thanks, maybe can move or slot it a bit.

rmcomprandy wrote:Simply correct the timing pointer you have or get a different one.

Best idea....

I have very seldom had a balancer that had the timing marks 100% correct. Just correct the pointer as was stated above.

KFM has a nice adjustable pointer !! only for belt drive I think tho?

Thanks for the help. Here is what I did, turned crank to 20* ATDC, installed piston stop thru sparkplug hole, rotated crank to where it stopped at 14* BTDC = 34* difference, divide by 2 = 17*.... moved crank 17 * which now pointer reads 3* ATDC....slotted stock pointer to then set on 0* TDC. Thanks again to all

Be sure to back the valves off on that cylinder your checking, the piston stop can bend a valve.

Good idea. None of my rockers are installed yet, so no contact with valves. I found some elgin .137 wall 3/8 pushrods, will be going on tonight, along with crower SS rockers.