C2 distributor tack drive ratio and tach repair

[Jerry G.]

I am "restoring" my race car to the way it was back in the sixties and have run into a question. Does the tach drive distributor for a C2 Corvette drive the tach at a one to one ration. ie at 5000 RPM of the motor is the tach drive cable turning at 5000 RPM? The second part of this question is aimed at you guys who may have contacts in instrument repair services. The tach that is going into the race car is a Jones accutrack mechanical tachometer . I'm looking for someone familiar with these tachs who can clean and adjust as needed. Any suggestions. Jerry

[Joe L.]

Re: C2 distributor tack drive ratio and tach repair

I am "restoring" my race car to the way it was back in the sixties and have run into a question. Does the tach drive distributor for a C2 Corvette drive the tach at a one to one ration. ie at 5000 RPM of the motor is the tach drive cable turning at 5000 RPM? The second part of this question is aimed at you guys who may have contacts in instrument repair services. The tach that is going into the race car is a Jones accutrack mechanical tachometer . I'm looking for someone familiar with these tachs who can clean and adjust as needed. Any suggestions. Jerry

Jerry------

The distributor shaft turns at 1/2 engine RPM. The tach cable turns at the same speed as the distributor shaft. So, if the engine is turning 5000 RPM, the tach cable is turning at 2,500RPM.

By the way, NO Corvette mechanical tachometer is a direct drive type as used in some racing applications. Direct drive type tachometers were, apparently, too expensive for Chevrolet to use in a Corvette.