Special distrib. req'd for '67 BB cam oiling ?

[Joe L.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Wayne-
Interesting you quote my E-Bay listing-I stand by it. The requirement from my research of Delco blueprints and several original distributors with ID tags indicates; the unique housing is required on all 65-67 blocks for the reasons I indicated. I agree and indicated the "grooved" cam was a 65-66 deal only, as the 67 block was grooved. However, not until 68 was the dist lower boss, which feeds the LH lifter galley, completely enclosed-similar to a SB, which all SB distributors are fully grooved. If you can get a 65-66 block next to a 67 block, next to a 68 block, you will see the changes I refer to. I firmly believe all 65-67 blocks require this unique distributor housing. I also believe it untrue, that if you install one of these distributor in a later block, you would have a problem-if the distributor is installed in the correct location (per shop manual), the blocked area would not "cover" the oil galleys.
Now, for your #263: these were over-the-counter out of the "Performance Catalog" during the late 60's, early 70's. These ball bearing vs. bushing, fully mechanical, no vac canister units were available with and/or without the blocked lower housing with either the standard or reverse rotation (just a footnote-internal parts, including TI parts are not interchangeable with line units which all had vac canisters, including L-88). The intended application for the reverse unit was the gear drive cam L-88 (primarily intended for CANAM racing; GM, through Roger Penske, was heavily involved with at the time), but also Marine applications-think twin motors. Your date of 6 J 15-to me would be September 15, 1966-just right for a 67 or earlier block. I do not believe these units were available as late as 76 or 86 as you thought. By the way, I really am a Master Judge, with a Duntov Mark of Excellence and a National Top Flight to my name.
Mike Zamora
#12455

Mike------


The "partial groove" distributor housing was used on 1965-66 big block distributor housings. However, it is not required for such applications. The 1965 396 distributor housing was GM #1965974. The 1966 427 housing was GM #1966654. The 1966654 was discontinued from SERVICE and replaced by the 1965974 in May, 1968.

In August, 1971 the GM #1965974, the "partial groove" housing, was discontinued and replaced by GM #1851158, a "full groove" housing. If the 65-66 big block applications required a "partial groove" housing, there's no way that GM would have replaced it with a "full groove" housing. They would have either maintained availability of the 1965974 or they would have discontinued it without supercession.

The GM #1111263 "ball bearing" TI, SERVICE-only distributor was available until March, 1993. I don't know exactly when manufacture of it ceased, but I'm certain it was after 1990.

[Wayne M.]

Re: Special distrib. req'd for '67 BB cam oiling ?

....The "partial groove" distributor housing was used on 1965-66 big block distributor housings. However, it is not required for such applications. The 1965 396 distributor housing was GM #1965974. The 1966 427 housing was GM #1966654. The 1966654 was discontinued from SERVICE and replaced by the 1965974 in May, 1968....

Joe -- I'm getting slightly different parts service history in the '65-68 period. My '66 P&A30 (1st ed. Oct '65) shows '65 396 first design 1111093 as using the 1965974 distr. housing.

Then, next line, they show '65 396 [I assume 2nd design] and '66 Corvette (427) (exc. Sp. H/Per., A.I.R. (w/1111093, 1141, 1142) as using the 1966654 housing.

Parts history in the 1967 catalog (Oct '66) shows nothing.
The 1st ed '67 catalog (Oct '66) shows the same as '66 (ie. they didn't add the '67 distributors yet).

I don't have parts history in my '68 chassis catalog (Oct '67), but all '65-67 use the 1966654 (for distr's 1111093, 1141, 42, 1240, 47, 48, 58).

1968 chassis catalog shows the same as for '67 (ie. they hadn't yet added the '68 distr #s to the listing)

Parts history in the '69 catalog shows 1965974 replaced by 1966654 on 11-66 and ALSO shows what you've indicated (ie. that 1966654 replaced by 1965974 on 5-68). What's going on here ? Did GM locate more inventory and switch back ?

To be consistent, the Rev 7-69 chassis catalog shows 1965974 as the housing to service '65-67 (1111093, 1141, 42, 1240, 47, 48, 58). Then, for '68-69 they show the same housing servicing 1111293, 94, 96, 1926, 27, 28, 1950).

Now we KNOW the '68-up did not have the partially filled groove in PRODUCTION. So the question is, does the 1965974 represent a partial groove ?

A clue might be found in doing the same excercise for the '65-68 non-tach drive distributors for the other big block Chevrolets. We might find a more definitive change point to the full groove.

[Joe L.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Joe -- I'm getting slightly different parts service history in the '65-68 period. My '66 P&A30 (1st ed. Oct '65) shows '65 396 first design 1111093 as using the 1965974 distr. housing.

Then, next line, they show '65 396 [I assume 2nd design] and '66 Corvette (427) (exc. Sp. H/Per., A.I.R. (w/1111093, 1141, 1142) as using the 1966654 housing.

Parts history in the 1967 catalog (Oct '66) shows nothing.
The 1st ed '67 catalog (Oct '66) shows the same as '66 (ie. they didn't add the '67 distributors yet).

I don't have parts history in my '68 chassis catalog (Oct '67), but all '65-67 use the 1966654 (for distr's 1111093, 1141, 42, 1240, 47, 48, 58).

1968 chassis catalog shows the same as for '67 (ie. they hadn't yet added the '68 distr #s to the listing)

Parts history in the '69 catalog shows 1965974 replaced by 1966654 on 11-66 and ALSO shows what you've indicated (ie. that 1966654 replaced by 1965974 on 5-68). What's going on here ? Did GM locate more inventory and switch back ?

To be consistent, the Rev 7-69 chassis catalog shows 1965974 as the housing to service '65-67 (1111093, 1141, 42, 1240, 47, 48, 58). Then, for '68-69 they show the same housing servicing 1111293, 94, 96, 1926, 27, 28, 1950).

Now we KNOW the '68-up did not have the partially filled groove in PRODUCTION. So the question is, does the 1965974 represent a partial groove ?

A clue might be found in doing the same excercise for the '65-68 non-tach drive distributors for the other big block Chevrolets. We might find a more definitive change point to the full groove.

Wayne------

It is possible that the 1965974 was a "full groove" housing. It's only by inference that I figured it was a "partial groove" housing (i.e. IF 1965 L-78 used a partial groove and this housing was the one originally used, then it must be a "partial groove" housing). However, it is possible that the "partial groove" housing was never available in SERVICE. However, if that's the case, I don't understand why there was a different housing shown for big blocks and small blocks in 1965 and 1966. In other words, if the configuration of the oil groove was not different, what was?

It's also possible that only the 1966654 was the "partial groove" housing. Or, it's possible it it was a "full groove" housing.

The housing used for non-Corvette big blocks was GM #1966629 for 1965-66 and GM #1967054 for 1967. The GM #1966629 was discontinued in December, 1966 and replaced by GM #1966407. The latter was used for all small block and big block applications until it was discontinued without supercession in July, 1989.

The GM #1967054 was discontinued without supercession in March, 1972.

[Mike Z.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Joe-
I follow your thinking and agree it does not make sense that GM would have replaced a line P/N with a service number having a fully grooved housing if not correct and serviceable for the application. However, along that same line: I have copies of several original Delco blueprints; in particular a #093 showing the design changes through 4/66 including 1st & 2nd design and a #258-both of which show the partial block on the housings. I see what probably is the housing P/N change you mention-to add a drain hole and add .0002" to a portion of the housing 2-9-66, which seems to agree with your data. Unfortunately, the drawings do not have the housing part number, just all the physical dimensions, so I am unable to confirm P/N's.
Now, consider this: along the same lines as you have suggested regarding the service replacements for 65-67 not requiring the partial groove---Why would GM spend the money to tool up a totally unique housing for the early BB if it was not really required? Many of the comments as to the need for the partial groove seems to swirl around the grooved cam of the 65-66 motor, but in fact the partial groove of the distributor housing has nothing to do with the cam or rear cam journal. I contend, based on viewing bare blocks of 66,67 & 68 vintage next to each other, the partial groove has everything to do with the lower distributor bore not being fully enclosed on 65-67 blocks. I realize the 67 block no longer required the grooved cam, but it is not fully enclosed in the lower dist bore, which was corrected with the 68 block. So, for me and my 2 early BB motors, I will go with original Delco blueprints and my personal observation of the changes made to the engine block-and isn't just possible, several years after the original design work, some Jr. engineer in his eagerness to save the company money, missed the reason the original engineers designed the original distributor housing?
Thanks for the additional info on the #263-I was not aware it was available as late as early 90's. Since, it was never used as original equipment, I really did not worry about it too much. I have had a few of them and find them to be a really nice piece (for racing), but since I concern myself with originality, I just resell, since none of the parts are interchangeable with an OEM unit; except for the magnet and coil bobbin, but not the base plate, pole piece, or mainshaft. Here again, since this is a service replace or performance unit-why would GM make versions with and without the partial groove; if all applications, as you suggest, would work with the fully grooved housing? We are second guessing GM on all these questions, but I truly believe the original engineers knew what they were doing.
Mike Zamora
#12455

[Steven S.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Some pictures and/or blueprints of the blocks in the area in question would really add to this discussion. I'd like to see what Mike is talking about to understand better where he is coming from.

[Bill M.]

Re: Special distrib. req'd for '67 BB cam oiling ?

isn't just possible, several years after the original design work, some Jr. engineer in his eagerness to save the company money, missed the reason the original engineers designed the original distributor housing? We are second guessing GM on all these questions, but I truly believe the original engineers knew what they were doing.
Mike Zamora
#12455

I'll bet the "junior" engineer designed the BB oiling system, and once it hit production an "old timer" reduced the cost and increased the reliability by eliminating the grooved cam and 3-hole rear cam bearing, and making sure you couldn't starve the driver side oil gallery even if you installed the distributor wrong. The "old timer" probably lived through the 265/283 cam oiling changes, where if you installed the 265 distributor wrong, you introduced a huge internal oil leak.

[John H.]

Re: Special distrib. req'd for '67 BB cam oiling ?

I'll bet the "junior" engineer designed the BB oiling system, and once it hit production an "old timer" reduced the cost and increased the reliability by eliminating the grooved cam and 3-hole rear cam bearing, and making sure you couldn't starve the driver side oil gallery even if you installed the distributor wrong. The "old timer" probably lived through the 265/283 cam oiling changes, where if you installed the 265 distributor wrong, you introduced a huge internal oil leak.

Bill -

You beat me to it - after the debacle with the '55-'56 265 oiling issues (cured with the '57 block machining and distributor annulus change), all memory was lost, and they turned right around and made exactly the same mistake again in '65 on the big-block, and cured it in '67. The big-block group speaketh not to the small-block group (yes, they were separate design groups).

[Charles A.]

Re: Special distrib. req'd for '67 BB cam oiling ?

I have read the entire discussion and I am a little confused. I just had built a 427 engine with a 351 block. Is it OK to use a full groove distributor housing just like the one in my 327 or do I have to use a partial groove distributor housing?

[Steven S.]

Re: Special distrib. req'd for '67 BB cam oiling ?

I believe the answer is yes

[Joe L.]

Re: Special distrib. req'd for '67 BB cam oiling ?

I have read the entire discussion and I am a little confused. I just had built a 427 engine with a 351 block. Is it OK to use a full groove distributor housing just like the one in my 327 or do I have to use a partial groove distributor housing?

Charles-----


As far as I know, all engines with the 351 block originally used distributor housings with a FULL ROUND oil groove. In any event, GM later replaced ALL earlier distributor housings, including those using the "half-round" oiling groove with the FULL ROUND. Therefore GM approves of the use of the FULL ROUND configuration for all engines.

[Wayne M.]

Re: Special distrib. req'd for '67 BB cam oiling ?

.....In any event, GM later replaced ALL earlier distributor housings, including those using the "half-round" oiling groove with the FULL ROUND. Therefore GM approves of the use of the FULL ROUND configuration for all engines.

Joe -- can I assume that the above refers strictly to TFP and service units for same ? I've got this nagging suspicion that for the always OTC race ball bearing distributor 1111263, they retained the groove and the reverse driven gear well into the '70s and even the '80s. In fact they may have listed two versions of the '263'; the other without the "half-round" and probably the conventional driven gear rotation.

The reason I say this is because of my NOS unit with a tag 6J15 (1976 ?, 1986 ?), and has the indicators, like the magnet with lips, the separate white and green wires (also has reverse driven gear). I suspect this was to support the professional racing world.

[Joe L.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Joe -- can I assume that the above refers strictly to TFP and service units for same ? I've got this nagging suspicion that for the always OTC race ball bearing distributor 1111263, they retained the groove and the reverse driven gear well into the '70s and even the '80s. In fact they may have listed two versions of the '263'; the other without the "half-round" and probably the conventional driven gear rotation.

The reason I say this is because of my NOS unit with a tag 6J15 (1976 ?, 1986 ?), and has the indicators, like the magnet with lips, the separate white and green wires (also has reverse driven gear). I suspect this was to support the professional racing world.

Wayne------


As far as I know, the '263' SERVICE-only distributor was always manufactured with the "half round" oiling groove. I do not know of any version of it with a full round groove.

I suspect, here's why: with respect to the cast iron distributor housings, the oiling groove was a feature of the castings and not the subsequent finished machining. I suspect that when the 1111263 was originally conceived, there was a PRESUMED necessity or desire to use the half-round configuration for early big blocks. So, the special housing used only for the 1111263 was designed around the half-round configuration.

Since the sales of this unit were probably quite low, there was no "impetus" to change the SPECIAL casting for the housing to the full-round as there was for all the other SERVICE distributors and SERVICE housings. Of course, the full round configuration could have been machined into the housing but I suspect that Delco-Remy didn't have this machining capability or, at least, weren't set up for it. So, since the half-round configuration would work for all big blocks, they just left it that way.

[Mike Z.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Wayne & Joe-as you knowledgeable guys probably know, the #263 TI unit was only available through the Performance Catalog over the counter-never was a line unit. I have had probably 5 or 6 of these units cross my work bench and have seen some with a partial groove and some fully grooved and even a reverse rotation-all with the same #263 ID band. So, I do not believe one can saw it was always one way or the other. Does anyone have a copy of the Performance Catalog from the late 60's early 70's? (early catalog would probably show 3 versions of the same P/N). The oldest one I have is like early-mid 80's and I don't see a #263 listed.

Charles, I have to go back to your question as to if the #351 block required the partial groove: not to belabor the question, all I can say is: all of the 67 BB distributor applications; #141, 247, 248, 294, 240, & 258 all have a partial groove, not a fully groove housing (point or TI makes no difference). I have tried to explain my position as to the reasoning, but apparently "The General" saw a need for the partial groove in the 67 BB including the #351 block. So, my answer is still NO! it is not recommended to run a fully grooved distributor housing.
MichaelZ505

[Mark L.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Mike/Joe,
The original distributor out of my Jan 67 BB is a partial groove. I don't know if this continued throughout the model year which may be what is causing the confusion.

[Joe L.]

Re: Special distrib. req'd for '67 BB cam oiling ?

Wayne & Joe-as you knowledgeable guys probably know, the #263 TI unit was only available through the Performance Catalog over the counter-never was a line unit. I have had probably 5 or 6 of these units cross my work bench and have seen some with a partial groove and some fully grooved and even a reverse rotation-all with the same #263 ID band. So, I do not believe one can saw it was always one way or the other. Does anyone have a copy of the Performance Catalog from the late 60's early 70's? (early catalog would probably show 3 versions of the same P/N). The oldest one I have is like early-mid 80's and I don't see a #263 listed.

Charles, I have to go back to your question as to if the #351 block required the partial groove: not to belabor the question, all I can say is: all of the 67 BB distributor applications; #141, 247, 248, 294, 240, & 258 all have a partial groove, not a fully groove housing (point or TI makes no difference). I have tried to explain my position as to the reasoning, but apparently "The General" saw a need for the partial groove in the 67 BB including the #351 block. So, my answer is still NO! it is not recommended to run a fully grooved distributor housing.
MichaelZ505

Mike-----


Personally, I have never seen a GM #1111263 distributor with anything but a "half round" oil groove. I have seen them with a standard drive gear, but those were not NOS units and were likely changed at some point. It's very possible that a "full round" groove could have been added to the distributor housing, especially if the groove were machined rather than as-cast. IF any distributor similar to the 1111263 except for the configuration of the oil groove had been available, I would have expected it to have had a different part number. Going back to 1974 performance parts catalogs, I can find no such part number.

It's very possible that some or all 1967 big block distributors did have the "half-round" configuration. However, I believe the question here is if that configuration is necessary.

As I mentioned previously and regardless of what was originally used for any distributor, GM replaced, for SERVICE, ALL of the 62-74 distributor housings with a housing that had a full round oil groove configuration. There is no way that they would have done this if a half-round configuration was REQUIRED for some 62-74 applications, including 65-67 big blocks.