Distributor Rotor

[Jeff S.]

Can anyone verify from recent purchase/experience that currently available NAPA/ECHLIN RR 1670 is dimensionally a "long tip - short gap" rotor? There are posts in the archive section that so indicate, but they are predominantly from ancient times. Thanks.

[John D.]

Re: Distributor Rotor

Jeff ,NAPA has not had the long tip rotor in ages. John

[Hank D.]

Re: Distributor Rotor

Try this.....https://www.corvettecentral.com/c3-6...%2btip%2brotor

[Mike T.]

Re: Distributor Rotor

Jeff - I have a new NAPA 1670 rotor, how do you measure one when looking for that extended tip dimension?
DSCN6212.jpg

[Owen L.]

Re: Distributor Rotor

Mike, can you measure your cap from arrow to arrow?
DSCN6212.jpg

For my 4000+ misfire, someone suggested I have a short-arm cap but they didn't respond with any further info on how to tell.

Maybe a measure how far the tip is over or under a vertical line with the lower part of the cap.
DSCN6212.jpg

[Mike T.]

Re: Distributor Rotor

It appears I'm still having issues posting pics. One time the orientation is correct, next time, the pic is turned 90-degrees. Started a 'ticket' and John W corrected it for me but for the life of me, still can't figure out how to simply rotate the pic.
In any case, notice the one pic that shows the square sitting flat on the workbench? Notice the taper present in the rotor skirt? Anyway, when I have the square making contact to the lower portion of that skirt, the gap appears to be an exact 1/4-inch.
IMG_1523.jpgIMG_1522.jpg

[Owen L.]

Re: Distributor Rotor

It appears I'm still having issues posting pics. One time the orientation is correct, next time, the pic is turned 90-degrees. Started a 'ticket' and John W corrected it for me but for the life of me, still can't figure out how to simply rotate the pic.
In any case, notice the one pic that shows the square sitting flat on the workbench? Notice the taper present in the rotor skirt? Anyway, when I have the square making contact to the lower portion of that skirt, the gap appears to be an exact 1/4-inch.

(rotated on my Mac)
That's perfect, thank you. Now to find out if this is "long" or not.
IMG_1522.jpgIMG_1523.jpg

[Leif A.]

Re: Distributor Rotor

Jeff,
Zip has the correct extended tip rotor in stock.

https://www.zip-corvette.com/57-74-1x4-distributor-rotor.html

"New reproduction "black" distributor rotor for 1957-1974 Corvettes with 1x4 distributor. Features the correct extended copper tip that closes the gap left by other replacement & current GM rotors. Eliminating the gap reduces poor start conditions, eliminates crossfires, misfires and fouled plugs due to weak spark conditions. Includes mount screws."

[Michael M.]

Re: Distributor Rotor

It's hard to beat the Delco-Remy D-409 rotor. I did find one very close that Accel makes or made. Both rotors have the long tip.

[Owen L.]

Re: Distributor Rotor

It's hard to beat the Delco-Remy D-409 rotor. I did find one very close that Accel makes or made. Both rotors have the long tip.

Can you do a measurement like Mike did above to see how far extended it is? (edit: Maybe that's a silly question as there is an ebay seller saying it's .0028" longer, which is pretty hard to measure this way.)

[Michael M.]

Re: Distributor Rotor

Owen,

My measurement says 7/8" in length on both rotors.

[Owen L.]

Re: Distributor Rotor

Owen,

My measurement says 7/8" in length on both rotors.

Is there any way to do a setup like Mike T shows here? I realized the length isn't as important as the projection from the cap's plastic body. He shows 1/4" gap.