quote:

Originally posted by BP758:
If I’ve figured correctly we have 97 * overlap.
That’s on the 636 and 650 motors.

If you are referring to over pal at 50, check again!

It is an Oakley engine and he won't give much info on cam specs.

The longer the rod the longer the piston sits (duell time) at TDC

Yes correct that was adv. .050 is 63.5

Message sent

Not saying anything wrong with most of the info being passed along in this thread but I also feel a simple leak down test is being over complicated too

I'm not sure how we got into the weeds of camshaft overlap etc.

quote:

Originally posted by Bucky:
I'm not sure how we got into the weeds of camshaft overlap etc.

Originally posted by inferno camaro:
I never use to remove my rockers but really struggle to get this one not to turn when putting air to it. What procedure do you use to get it TDC on each cylinder?
I turn it over until both rockers are loose (seems tough to do with large overlap cam)

quote:

Originally posted by Bucky:
I'm not sure how we got into the weeds of camshaft overlap etc.

Kind of wondering what cam has to do with leak test period.

I ahve done leak test 2 ways. Piston TDC which is harder to hit perfect. I have also pulled rockers a just thro the air to cylinder. First check ring seal at tdc and second at bottom. I figure if both are good the cylinder has to be pretty close to perfectly round and rings are good.

It is not rocket science just air in and if it comes out you will hear where leak is.

Don't put more than 100 psi, or less than 60 psi into the cylinder, to ease the process.

I bring #1 to TDC firing position, check, move crank 90 degrees, moving through the firing order.
I always rap the valves while the air is on to check seats.