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Previous Next Up Topic Engines / Corvair Power / excessive timing? (15460 hits)
By Paul H 2066 Date 2010-03-04 21:59 Edited 2010-03-04 23:03
I recently rebuilt a 64 110 for a buggy and upon the initial start up the timing had to be advanced to approximately 30 degrees to run. I double checked the cam to crank timing marks during the engine assembly but now I'm second guessing my work.  I believe I am experiencing carburetor problems as well but I fail to see where this would affect the timing this drastically.  The distributor has a Petronox to eliminate the points and seems to be fine.  The heads were modified by milling away the intake manifolds and welding a port for each cylinder and a manifold was fabricated to attach to each port. This makes for a six runner manifold fitted with a Motorcraft/Holly 2150 type carburetor.  The motor seems to run fine except for what I attribute to the carburetor  problems. Is there a simple way to verify I didn't goof on the cam timing? Any advice is greatly appreciated.

Thanks Paul Hoffman
By ManxRob Date 2010-03-05 04:48
That sounds like a sweet looking Corvair engine! Have you verified that the harmonic balancer hasn't slipped moving the timing marks?

Also, the CorvairCenter forum has a lot of Corvair technical knowledge:

By Paul H 2066 Date 2010-03-05 05:02
Thanks for the reply. The factory places a small mark on the inside section of the harmonic balancer to indicate any unwanted movement and mine is one or two degrees off but still within the acceptable range.
I usually set it to the specs and tune by ear or seat of the pants just taking note of any knocking. I purchased the buggy with this setup and rebuilt the motor since it was pretty tired. I know I have some issues with the carburetor to work out but I don't see that affecting the timing that much.
Thanks again for your thoughts.
Paul Hoffman
By Bob E 1463 Date 2010-04-05 23:05
I had similar confusion with my Viar, and I'm a 1st timer using the six.  Always been a VW guy prior.

I had to add in so much BTDC that I'm completely off the mark on the case, probably 18-20 at idle and my dizzy only adds another 8-10 added in once rev'ed up.

But, it runs fine and does not ping?  I think these engines like it?
Boston Bob E. - -
By Leon R 2038 Date 2010-04-08 02:20
I would look VERY closely at the rubber ring in the balancer it is common for the rubber to break loose If you run Corvair power you really should come visit the corvair forums I came here looking for chassis info on corvair powered dune buggies because I have spare drive lines and had a Bushwacker VW buggy as a teen.
By Bob E 1463 Date 2010-04-10 12:29
Leon, thanks for the links, and your right, I should visit them more often.  Great information and help can be found there also. 

In my case, my engine is little bit of a Corvair mutt and it's not the harmonic balancer.  I'm using an early short stroke crank with the solid crank pulley, but with the better breathing 140 heads.  The power is smooth with a good bottom end and rev's freely,  but obviously I'm missing out on the extra grunt of the longer crank.

Thanks for the links.
Boston Bob E. - -
Previous Next Up Topic Engines / Corvair Power / excessive timing? (15460 hits)

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