Just bought a running 292 . While pulling it down for overhaul found the cam gear is 180 degrees off. Been working on y-blocks for over 50 years have never seen this before. Any idea how this is possible.

If it was running, then you are mistaken.  Remember, it takes 2 revolutions of the crank for 1 revolution of the cam so at one point it will appear to be 180 off.


Lawrenceville, GA

Is the timing marks on the cam and crank gear 12 teeth apart on #1 compression stroke?

No.  That is a common misunderstanding.  It is with #6 at tdc on compression.


Lawrenceville, GA

Wow !! I can not believe I forgot that might be the case. Thanks.

Dave, I would trust Charlie's advice on this. He has helped me out many times!

Rono

  Ron Lane,  Meridian, ID

Thanks Ron. All the years I've worked on these y-blocks not sure I was aware of this. I lined the timing chain up then put everything together, set the motor in, then rolled #1 up and set the distributor in. 

With the gears installed correctly, #1 and #6 will always be at tdc at the same time only one will be on compression and the other will be on exhaust.


Lawrenceville, GA

If the gears are installed with #1 on compression, can the distributor be moved 180* to compensate?

Butch Lawson

Manchester,  TN

No.  If you do that, then the cam timing will be wrong and it will not matter if the ignition timing is correct, the engine will not run.

It would be impossible to do that if the gears are installed correctly, with the dots at 3:00 and 12 pins between.  They only go on one way.


Lawrenceville, GA