Ignition Points '57 thru '74 ? -- application

[Wayne M.]

Looking at a 'stash' of small Delco boxes I got on eBay, and there's 3 of contact sets #1966294 (D-112P). My Chevrolet parts books show this number starting in service exclusively for 427's (ie. not 396's) in 1966; on obviously non-transistorized cars.

The general-use contact sets for all V8's (exc. 427, exc. dual points) seem to be #1931988 (D-106P) for '57 thru '70 (my latest parts book) [exc. dual points, exc. 427's, exc. '70 350/350hp].

By the orange/white/black box design, I'd say these were of the '66-69 timeframe. The D-112P's seem to be visually identical to an NOS D-106P that I have, except that the spring tension is at least 50% greater on the 112's. BTW a red/white/blue box of 10 foil wraped packs of these D-112P's just sold for $188 on eBay, so someone must want them real bad .

Now I always thought that higher spring rates helped avoid points "bounce" at high rpm's. So why restrict these points to the 427's (ie. L36, L68, etc) which have redlines lower than some of the high revving small blocks ? They did call for the '112P' on the 1970 350hp small block, though -- that's the newest parts book I have, so I don't know the story thru 1974.

Then there's the #1966289 (D-106PS) which I assume is identical to the '106P' except has a screw terminal for the condenser and negative lead to the coil, rather than the clip-on type of terminal. My 1970 Corvette parts book shows this contact set as being an alternate to the '106P' for '58 thru '67 (exc. 427).

Can anyone clear this up for me, and state what Corvettes originally came with the D-112P contact set ?

[Duke W.]

Re: Ignition Points '57 thru '74 ? -- application

The D112P is the higher breaker arm tension - 28-32 oz. versus 19-23 for all the other sets, which include screw terminal, clip on, and "uniset".

I don't think the D112P was released until about 1966 (Joe probably knows), and they were OE on a number of "muscle car engines" of that era including some non-TI Chevrolet big blocks, but I don't think this included any of the Corvette hydraulic lifter big blocks (or ANY Corvette engine for that matter), and all the mechanical lifter big blocks required TI. The CSMs and AMA specs usually list breaker arm tension for all engines with point distributors.

Of course, by 1966 mechanical lifter small blocks were history - at least for a time, and Chevrolet never bothered to "upgrade" the service part, but they certainly would have been a good idea for L-79.

I recommend the D112P (equivalents are available today like the Echlin CS86) for all engines with redlines above 5500.

The various standard tension sets are fine for most other applications, and which one you use is often just a matter of convenience or availability.

I don't see the point of paying big bucks for an old D112P since Standard Motor Products makes an equivalent set that is sold under the various traditional brand names. Like the D112P, this is a screw terminal set, and I don't think it can be distinguished from D112P without close scrutiny, which doesn't include just lifting the window for a peak at them as mounted.

Duke

[Joe L.]

Re: Ignition Points '57 thru '74 ? -- application

Looking at a 'stash' of small Delco boxes I got on eBay, and there's 3 of contact sets #1966294 (D-112P). My Chevrolet parts books show this number starting in service exclusively for 427's (ie. not 396's) in 1966; on obviously non-transistorized cars.

The general-use contact sets for all V8's (exc. 427, exc. dual points) seem to be #1931988 (D-106P) for '57 thru '70 (my latest parts book) [exc. dual points, exc. 427's, exc. '70 350/350hp].

By the orange/white/black box design, I'd say these were of the '66-69 timeframe. The D-112P's seem to be visually identical to an NOS D-106P that I have, except that the spring tension is at least 50% greater on the 112's. BTW a red/white/blue box of 10 foil wraped packs of these D-112P's just sold for $188 on eBay, so someone must want them real bad .

Now I always thought that higher spring rates helped avoid points "bounce" at high rpm's. So why restrict these points to the 427's (ie. L36, L68, etc) which have redlines lower than some of the high revving small blocks ? They did call for the '112P' on the 1970 350hp small block, though -- that's the newest parts book I have, so I don't know the story thru 1974.

Then there's the #1966289 (D-106PS) which I assume is identical to the '106P' except has a screw terminal for the condenser and negative lead to the coil, rather than the clip-on type of terminal. My 1970 Corvette parts book shows this contact set as being an alternate to the '106P' for '58 thru '67 (exc. 427).

Can anyone clear this up for me, and state what Corvettes originally came with the D-112P contact set ?

Wayne-----


The GM #1966294, aka Delco D112P, was first used for 1965 Chevrolet passenger car with L-78 and without K-66. As far as Corvettes go, GM and Delco-Remy say it was used for the following applications:

1966-----L-36

1967-----L-36, L-68

1968-----L-36, L-68

1969-----L-36, L-68

1970-----L-46, LT-1 (IF any were made without K-66), LS-5

1971-----BASE, LS-5

1972-74--ALL

The 1966294 was also used for other Chevrolet models including the following:

1966-69 with L-36, L-72, L-78

1967-69 302 (Z/28)

1970 with L-34 or L-78 with THM and all 454

most 1971-74 with 350 cid and 4 barrel carb

1971-74 with 454----ALL

Obviously, the above list of other Chevrolet models does not include engines available with and equipped with K-66.

The GM #1966294 was also used for the following Pontiac applications:

1969-----428HD with auto trans

1970-----455 cid except Bonneville

1971-74--ALL with 4 barrel carb.

I can't find any other applications for the GM #1966294 point set.

GM #1966294 was discontinued from SERVICE in March, 1988.

[Wayne M.]

Re: Ignition Points '57 thru '74 ? -- application

Wayne-----

The GM #1966294, aka Delco D112P, was first used for 1965 Chevrolet passenger car with L-78 and without K-66........
......GM #1966294 was discontinued from SERVICE in March, 1988.

Joe L. -- thanks; your list is quite extensive and much longer than I'd imagined.

Duke W -- thanks for the breaker arm tension figures, etc. I just went by 'feel', but the D-112P's were definitely higher than the D-106P's, and you confirmed.
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Other questions re the points bump cam (rotating pole piece w/weight base); I see that many were listed simultaneously in the parts books, probably due to requirement for different auto-cam weights advance curve spec's. In all of these, was the contour of the octagonal cam identical ? With the higher points spring tension, was there accelerated wear of the cam itself, or the plastic contact 'rider' on the points arm ? Did the uniset incorporate some sort of cam lubrication ?

TIA

[Joe L.]

Re: Ignition Points '57 thru '74 ? -- application

Joe L. -- thanks; your list is quite extensive and much longer than I'd imagined.

Duke W -- thanks for the breaker arm tension figures, etc. I just went by 'feel', but the D-112P's were definitely higher than the D-106P's, and you confirmed.
---------------
Other questions re the points bump cam (rotating pole piece w/weight base); I see that many were listed simultaneously in the parts books, probably due to requirement for different auto-cam weights advance curve spec's. In all of these, was the contour of the octagonal cam identical ? With the higher points spring tension, was there accelerated wear of the cam itself, or the plastic contact 'rider' on the points arm ? Did the uniset incorporate some sort of cam lubrication ?

TIA

Wayne-----


I don't think there was any difference in the configuration of the cam section. I believe that all the differences related to the weight plate. Although once-upon-a-time there were a plethora of different cams across the Delco-Remy distributor part numbers, they were ultimately consolidated into about 4 part numbers, with only 2 widely applicable.

Distributors with Uniset points used the same cam lubricator as with standard point and condenser. There was no lubricator integral with Uniset.