Hat's off to Jerry Gollnick

[Jerry G.]

Re: Hat's off to Jerry Gollnick

Clean as a whistle.

[Clem Z.]

Re: Hat's off to Jerry Gollnick

I used Marvel mystery oil, no change. I soaked the cables in synthetic gear oil, no change. i used the dow grease, no change. I used the stub housing, no change. I used a more flexible cable, no change. THe pump was built by someone I consider the best in the business and it tested well within spec. I think it's either a cable quality/specification problem or an internal problem to the fuel meter that causes cavitation.( not likely). I am open to ALL ideas and i appreciate the old pros experience on this. I suspect there is something that is obvious that i am missing. Jerry

are other corvette racers who run with you having the same problem ??

[Jerry G.]

Re: Hat's off to Jerry Gollnick

really good question. I was the only C2 corvette racer with Fuel Injection. There were some specials and C1 with FI. I don't know if they were having same problems. I doubt it. If anybody knows someone racing an FI please chime in. I'd be interested in their shift point RPM.

[Clem Z.]

Re: Hat's off to Jerry Gollnick

really good question. I was the only C2 corvette racer with Fuel Injection. There were some specials and C1 with FI. I don't know if they were having same problems. I doubt it. If anybody knows someone racing an FI please chime in. I'd be interested in their shift point RPM.

the cable breaking was happening back when these corvette were being raced new. how often this happened i do not remember but it happen back then that is why the gulf corvettes ran without the outer housing so the driver could change it out on the track.

[Clem Z.]

Re: Hat's off to Jerry Gollnick

how about a solid shaft and a couple of small CV joints ??

[Jerry G.]

Re: Hat's off to Jerry Gollnick

A buddy of mine who is a machinist suggested that. Do you know of a supplier?

[Clem Z.]

Re: Hat's off to Jerry Gollnick

A buddy of mine who is a machinist suggested that. Do you know of a supplier?

try goggle and see what you find.

[Clem Z.]

Re: Hat's off to Jerry Gollnick

looks like RC cars and trucks use them. are they strong enough ?? http://www.4wheeloffroad.com/feature.../photo_08.html

[George J.]

Re: Hat's off to Jerry Gollnick

Jerry,
what about the clearance issue you were talking to me about at Laguna? Also, are the cables just snapping, or unravelling? At what point of the cable does it happen?
It is hard to believe that at 6500rpms they're ok, but at 7000-7500rpms they're not.

George

[Jerry G.]

Re: Hat's off to Jerry Gollnick

It's a fatigue failure. What i remember from my undergrad days in mechanical Engineering was a fatigue failure curve that related the number of cycles(flex) with the level of stress(torque). This curve is developed for particular metallurgy for the material in the cable. The variables here are stress and the metallurgy of the cable. I will straighten the cable to reduce bending, but, I don't think the torque is all that much higher in my application than originally designed, in fact after testing the pumps fall well within the original specifications, so I'm led to the materials todays cables are made of is inferior to the original design specifications. I will have cables custom made for me that will help in this area. The other alternative is a small shaft like Clem is suggesting, a good idea.
it's an interesting problem. Jerry

[Clem Z.]

Re: Hat's off to Jerry Gollnick

It's a fatigue failure. What i remember from my undergrad days in mechanical Engineering was a fatigue failure curve that related the number of cycles(flex) with the level of stress(torque). This curve is developed for particular metallurgy for the material in the cable. The variables here are stress and the metallurgy of the cable. I will straighten the cable to reduce bending, but, I don't think the torque is all that much higher in my application than originally designed, in fact after testing the pumps fall well within the original specifications, so I'm led to the materials todays cables are made of is inferior to the original design specifications. I will have cables custom made for me that will help in this area. The other alternative is a small shaft like Clem is suggesting, a good idea.
it's an interesting problem. Jerry

the original GM cables were breaking in racing back in the late 50s and early 60s. i never owned a FI corvette back in the day so i don't know if the cables were a problem on the street.

[Paul Y.]

Re: Hat's off to Jerry Gollnick

the original GM cables were breaking in racing back in the late 50s and early 60s. i never owned a FI corvette back in the day so i don't know if the cables were a problem on the street.

I have only switched one cable out in a 100K miles of street/highway driving. It never broke but it was coming unraveled and put holes in my fingers when I greased it. I have only used the old original cables and non of the repos.

[Clem Z.]

Re: Hat's off to Jerry Gollnick

it may have something to do with quick changes in engine RPM causing the momentum of the spinning gears to strain the drive cable

[Clem Z.]

Re: Hat's off to Jerry Gollnick

what material are the gears made from maybe having a set made from titanium would help cut down on the weight.

[Jerry G.]

Re: Hat's off to Jerry Gollnick

Pretty sure they are steel. I'm not sure it a mass issue as much as seal drag( a necessary evil of gear pumps). Tell me more about your thinking.