The RX7 maintenance manual's description of the CAS is rather sparse and I'm
not much of a mechanic either. The first photo is of the CAS with eShaft
set, according to the pulley timing mark, to 35 deg BTDC (Tracy Crooks
suggestion) and the second is with the CAS pointed to, what I think, Tracy
says to do. I never took the CAS shaft out of the front cover during the
rebuild.

Where is the CAS wheel, with the two pointers 180 deg from each other,
supposed to be pointing for a given eShaft position?

Jay

Yes but the gear could still be a tooth or two off.

Take the CAS out and do it like they do it in the shop manual.

Then check the timing and make a final adjustment.

Paul Lamar

-

Thanks Paul,
I did line up the marks on the CAS shaft and gear. What's confusing me is
that the RX7 manual is calling for setting the e shaft pulley at 5 deg AFTER
TDC and Tracy Crook, in the EC3 installation manual, says 35 deg BEFORE TDC.
Maybe I'm misreading something.

Jay

I think what happens is as you insert the CAS the gears are helical
so there is some twist. The bottom line is the electrical timing.
Tracy wants it at 35 BTDC so he can move the actual timing to 22 or so
BTDC. It is all in the software. When you hook up a timing light
and the engine is running at some useful RPM it should be around
20 degrees BTDC + or - 3 degrees. There is some advantage
at high altitude to advance the timing to as much as 35 degrees
BTDC. Tracy should explain more of what he is doing and why
he is doing it.

BTW I just picked up this computer board on Friday in Beverton OR
so as I write EFI software for it I will explain what I am doing
and why I am doing it. It is a very powerful computer with
2.9 million instructions per second and no less than 16 analog
to digital converters and seven hardware interrupts. It will
communicate with a net book mounted in the cockpit for a full
screen display.

http://www.zbasic.net/

Very easy to program. A caveman could do it :)

Paul Lamar