Gm rotor # 1852722 ?

[William C.]

Re: Gm rotor # 1852722 ?

When I did the Article, I purchased one of every available "high perf" rotor I could find (Still have most, available cheap) as I recall, none of them matched the original GM design. It's not a problem with a 250-300 hp engine, but with a real Corvette engine (11.0 to one compression) it can be an issue at redline.

[Timothy B.]

Re: Gm rotor # 1852722 ?

Supposedly it had the effect of raising the system voltage to fire the charge. Unfortunately (at least to a poor dumb ME) it doesn't make any sense from an e=ir standpoint as the 12v system energy doesn't really change it's energy capacity, and the rather abysmal results when one is used in an 11-1 compression engine would seem to verify my analysis on that point.

Bill,

I guess it's the same effect as resistor spark plugs, don't they increase spark energy because of the resistance?

[William C.]

Re: Gm rotor # 1852722 ?

So they say, but I never knew any racers who used resistor plugs, and they sure weren't oem in a '65 Corvette. You have to remember that the system is only capable of a certain voltage, given a certain energy level at the primary, which is limited by the old E=IR equation, Real world, the "E" rotor sucks in an 11 to 1 Corvette application.

[John D.]

Re: Gm rotor # 1852722 ?

Someone would ask here about the extended tip cap. Whew!!!
Anyhow for a short time NAPA had an extended tip rotor. Part # RR1670. Nice brown rotor which looked identicle to the ACCEL rotor. Very heavy duty, Riveted and extended tip. But it seems someone hit the warehouses and bought them out. Don't know who the turkey was though. JD

[Jim R.]

Re: Gm rotor # 1852722 ?

Bill was one of them the red msd 8467

When I did the Article, I purchased one of every available "high perf" rotor I could find (Still have most, available cheap) as I recall, none of them matched the original GM design. It's not a problem with a 250-300 hp engine, but with a real Corvette engine (11.0 to one compression) it can be an issue at redline.

[William C.]

Re: Gm rotor # 1852722 ?

Can't tell you now, been too long ago, but some were red, some tan, only real way to tell for sure is to measure against an original, even a well used one instantly can be seen as having a better tip length than anything I could find in the aftermarket. I purchased them from parts houses and race shops like Jegs and Summit racing. No real difference in the design, not ere equal to the early GM issue and like-era aftermarket items.

[Jim R.]

Re: Gm rotor # 1852722 ?

Bill is the one corvette central has the (kb1852722 aftermarket taiwan piece) same as the one listed in the driveline add, the cc#301032 rotor it looks the same.

[Ken A.]

Re: Gm rotor # 1852722 ?

There is only ONE US vendor that still makes distributor rotors & all are the same tip length. No matter what brand, they're all the same.

[William C.]

Re: Gm rotor # 1852722 ?

I can't say, have not had the opportunity to check them, but I don't think anyone is having one "special made". All the different suppliers I could find were repackaging something purchased from an automotive aftermarket supplier.

[Joe L.]

Re: Gm rotor # 1852722 ?

I believe '74 was the first year for the white rotor, but for several years before that, Delco had a black rotor with an "E" stamped on it, also a POS with a shortened tip.

Bill------


Yes, I believe the "white" rotor first appeared for the 1974 model year, although it's possible it was used for late 1973. That rotor was the GM #1852722.

As far as I know, the original "extended tip" rotor was the GM #1932015. This rotor was installed in PRODUCTION for 1963-68 Corvettes. For 1969 it was replaced by the GM #1971247 which I believe is the "E" stamped rotor and which has a reduced length contact. This rotor replaced the 1932015 for all SERVICE in October, 1969. Both of these rotors were "black" alkyd material.

In May, 1974 the GM #1852722 replaced the 1971247 for all SERVICE. The 1852722 has a reduced length contact like the 1971247. I believe the 1852722 was an actual Delco-Remy-manufactured piece for most, if not all, of its existence.

In March, 1994 the GM #1852722 was discontinued and replaced by GM #12338671. This is also a flimsy "white" rotor similar to the 1852722. It is not of Delco-Remy (or DELPHI) manufacture. I believe it's manufactured by Standard Motor Parts. I think it's still available.

[Wayne M.]

Re: Gm rotor # 1852722 ?

I believe the 1852722 was an actual Delco-Remy-manufactured piece for most, if not all, of its existence.....

Yes, you can barely see the Delco Remy made in USA imprint on the top of the white rotor I show in post #4. Might also add that it's about half the weight of the black Taiwan made long tip. And this came from the can with the plain (unpainted) metal top; the one I haven't opened yet (with the blue metal top) is of an earlier issue, I believe.

[William C.]

Re: Gm rotor # 1852722 ?

That fits with my recollection from the era. I was replacing the "E" rotors with the earlier styls as fast as I could back around '69, My distributor machine was very busy in that timeframe.

[Joe L.]

Re: Gm rotor # 1852722 ?

Yes, you can barely see the Delco Remy made in USA imprint on the top of the white rotor I show in post #4. Might also add that it's about half the weight of the black Taiwan made long tip. And this came from the can with the plain (unpainted) metal top; the one I haven't opened yet (with the blue metal top) is of an earlier issue, I believe.

Wayne-----


The "blue top" may be of an earlier issue, but as it's a GM #1852722, I'm sure it will be the same "white" rotor. There's an easy way to tell without opening it. Just weigh the complete opened package with the rotor and compare it to the weight of the unopened package. You'll need a gram scale to do this, of course.