Honda CB750 Sandcast

VIN and Engine Number Spread

kp · 57 · 19598

kp

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KP engine number 664 has a small vin pad as does 181. Marty K.
The reason I asked Marty about his Engine number pad is because the casting date is June 3. This means they were 1. still using the same sand box mould blanks in June to cast 664, 2. the codes are not dates at all (unlikely) or 3. the casting date quoted in the VIN registry is incorrect. If the latter 2 are not appropriate then we have a real dilemma.
Yabba Dabba KP


sandcastdoctor

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HELLO!! I'LL THROW AN IDEA OUT THERE ABOUT THE DIFFERENT COLOR DOTS ON THE ENGINE CASES. HOW ABOUT ONE COLOR DESIGNATING A PROBLEM WITH THAT PARTICULAR ENGINE, THE OTHER COLOR DESIGNATING THE REQUIRED REPAIRS WERE COMPLETED. COMMENTS??


DW69K0

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Quote
The reason I asked Marty about his Engine number pad is because the casting date is June 3. This means they were 1. still using the same sand box mould blanks in June to cast 664, 2. the codes are not dates at all (unlikely) or 3. the casting date quoted in the VIN registry is incorrect. If the latter 2 are not appropriate then we have a real dilemma.

OK now I am sounding like a stuck record, maybe the engines were not stamped until they were tested and close to the frame assembly. This theory answers some questions on how the E numbers don't always match-up closely to the frame numbering in several instances. This is all speculation as we don't know:
   1) When the engines tested fine there was a close frame/engine pairing, but in the few instances when     problems occurred the engines were repaired or scrapped.
   2) My guess is frames were almost always good, but engines had some problems.
   3) Honda would have needed to make every engine they assemble a good engines if they stamped them right after the casting.
   4) As noted, 7414 Frames had Sandcast engines (plus the know French Sandcasts).
   5) I would think some issues occurred once engines were assembled, so are there big gaps in the engine numbers? Are engine numbers not sequential? I would think not, but maybe.

In most production assembly operation, the serial numbers are not placed on the final product  until all components are proven to operate and meet quality standards. The Japanese had some of the highest, if not the highest quality standards in the world at this time, thanks to Deming.

We will more than likely never really know what happened on Honda's assembly line, but I am sure as more factory frame/engine pairing are known, we will gain additional insights.

DW


kp

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I don't think your sounding like a cracked record rather your giving logical consideration to possibilities. I'm just intrigued as to why Marty's narrow pad top case was cast in June when these cases seem to have stopped being cast in March. Maybe, and this is probably a wacko idea, the narrow pad case and the wide pad cases are incompatible.  Now there's a spanner in the works. Duane, taking one of your comments on board in that an engine is trashed because of a major fault then that engine number becomes useable or wasn't initially stamped or that a new top half was machined to replace a faulty case, thus the number needed to be restamped or whatever. I am totally at loss as to why a narrow pad case was cast in June
Marty, maybe you could do some detective work and see if there any differences between narrow pad cases and wide pad cases
Does anyone else have bare cases to compare. There has to be a reason
« Last Edit: April 27, 2016, 12:54:46 am by kp »
Yabba Dabba KP


cb7504

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I'll take a look and do some comparisons. Marty K.


4pots1969

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I don't think your sounding like a cracked record rather your giving logical consideration to possibilities. I'm just intrigued as to why Marty's narrow pad top case was cast in June when these cases seem to have stopped being cast in March. Maybe, and this is probably a wacko idea, the narrow pad case and the wide pad cases are incompatible.  Now there's a spanner in the works. Duane, taking one of your comments on board in that an engine is trashed because of a major fault then that engine number becomes useable or wasn't initially stamped or that a new top half was machined to replace a faulty case, thus the number needed to be restamped or whatever. I am totally at loss as to why a narrow pad case was cast in June
Marty, maybe you could do some detective work and see if there any differences between narrow pad cases and wide pad cases
Does anyone else have bare cases to compare. There has to be a reason

It is impossible to replace only the upper part of a housing engine because they are machined in pairs...
We must replace the lower and upper together..
It is possible that the guy who introduced the stamps in the mold was wrong numbers .... Or an old mold
was reused during the period of broad plates ...
The question to be asked ....
During the short period of blue and red points is that all motorcycles have received a blue or red dot?
It's not impossible, because we do not know why they were put on the engines ...
Personally, if I see a red or blue dot on my bike I take it off and maybe the guys did the same thing, set apart some for whom it did not matter..
« Last Edit: April 27, 2016, 10:14:48 am by 4pots1969 »


hondasan

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Regarding the question about a coloured dot on E1106, I really can't remember. 25 YEARS now since those cases were blasted and prepped for re-build, and still not re-assembled (and no digital camera back then to make recording of detail easy)!

Scary how life passes us by.

Chris R.
Chris R.
302/338


kp

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It is impossible to replace only the upper part of a housing engine because they are machined in pairs...
We must replace the lower and upper together..
Gerard you are incorrect. It is indeed possible to mix case halves. Maybe not feasible but certainly not impossible
Yabba Dabba KP


cb7504

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KP nice one, definitely can be done, but definitely not recommended. Marty K.
« Last Edit: April 27, 2016, 07:17:04 pm by cb7504 »


patriotcommercial

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You guys are evaluating the situation based on the assumption that all the engines and frames were numbered consecutively.  If they were batch manufacturing they may have had milestone goals.  The first period, days or a month for example the goal was 200 bikes.  If the frame manufacturing group hit the goal they built 200 frames numbered from 100 to 300.  The next batch of frames was slated to start at 301 and run to 501.  Mean while the engine manufacturing line only completed engine 100 to 275 as an example.  When the next batch production started they began with vin 300 but it went into frame 276 that was waiting for an engine. 

Maybe the frame and engine numbers. started with vin numbers matched to the start date of the batch regardless of where they finished the last batch ???


kenhan

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One important issue for Honda should be spare parts. In the parts lists all items are referred to frame Vin numbers, also the engine parts. In order for the customer to get the right engine parts Honda had to connect changed engine parts with fixed frame numbers. I know this is not correct every time but worth consider when E-vin are paired to frame Vins. Parts for the french sandcast will be very odd with this reasoning.
/Ken
1969 CB750 Sandcast #5084 - running
1969 CB750 Sandcast #5128 - Running
1970 CB750 next project
1975 K2 (K3-5 donīt exist in Sweden) - Running
1981 Goldwing 1100 Interstate


4pots1969

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It is impossible to replace only the upper part of a housing engine because they are machined in pairs...
We must replace the lower and upper together..
Gerard you are incorrect. It is indeed possible to mix case halves. Maybe not feasible but certainly not impossible

Yes, what is forbidden is not impossible... just forbidden !! I agree... ;D ;D ;D ;D
« Last Edit: April 28, 2016, 04:09:58 am by 4pots1969 »