Engine ID 472 cid help!- with picture....

[Geert-Jan]

Hi folks!

I have a 1968 Grecian white Caddy DeVille convertible and I'm trying for a while to get more information about the engine's history, without disassembling it. I know it's a donor engine and not authetic to the car but I'm curious to know what year it has it's origin. The possible range is 1970-1974. From the carb I don't get much information because it's a donor one either (7029232, which means a Rochester carb for a 1969 49-State Caddy with auto transmission). Today I crawled under the hood and shot a couple of pictures of the rear end of the block just behind the oil pressure switch (the red section of Michael Stamps picture in thread of june 17th 2007 (1968 Cadillac Fleetwood Brougham VIN question/decoding body name plate).

The engine block casting number is 1485200
The head casting numbers are 1497902
The engine serial casting number is 660192082 (see picture in detail)

Does anyone have, know or able to retreive the exact year of the engine (for example with a list of serial numbers)?

Thank you for your help!

Geert-Jan

[TJ Hopland]

The 5200 block was 70-76 same for both 500's and 472's.  Only slight mostly internal changes to take the longer stroke of the 500 and some slight changes in some of the oil system otherwise the same as the 68&9's.

The 902 heads were 71-73.   Small chamber (76cc) with smog rail.

The only major difference in the heads (at least for fairly stock applications) is if they are small or large chamber. 74-76 had a larger chamber (120cc) that made things a bit better for the low compression motors that were mandated by GM in 71. The first few years they just used pistons with a huge dish to lower the compression.  Im guessing in 74 they gave up trying to meet emissions and did the slight redesign on the head.  With the small chambers you can do either low or high comp.  The large chambers are pretty much designed for low comp.  The 68-70's were high comp.

Pistons and crank were the difference between the 500 & 472.  The 500 had about a 1/4 longer stroke than the 472 (and 425).  Measuring the stroke or looking at the casting number on the crank is the only way to tell for sure.

The major change in power over the years was other than the comp drop in 71 was the cams.

[Stampie]

The later engines used a partial VIN on the engine.  Looking at my 71 shop manual it gives a sample VIN of 683471Q100001 .  6 is Cadillac, 8347 is Series and Model, 1 is the model year, Q is the Plant and 100001 is the Broadcast Number.  Working backwards from yours I get Broadcast number of 192082.  That leaves 660.  I am assuming the 0 is really a Q for the plant.  That leaves us with a 6 for the model year.  So going off this I'm thinking it is a 76 engine and would have to be a 500 engine at that.  Maybe someone with a later shop manual can confirm this.

Stampie

[Stampie]

I just noticed the 902 heads part.  It is possible to rebuild a late block with early heads if you use the proper pistions.  You might want to do the rod down the sparkplug hole to find out if it is a 472 or 500.

Stampie

[Stampie]

Ok I just found my 73 manual and forgot about the R & S in the VIN.  The last nine of the sample VIN is R3Q100001 with R being 472 engine vs. S being 500 engine.  3 is the year and Q is plant still.  So ... I'm lost with our 660 or 66Q unless someone has a 76 manual to compare and see if it changed after they dropped the 472s.

Stampie

[Stampie]

Guess who just found their 76 Manual.  It gives last 9 of the sample VIN as S6Q100001.  The S being 500 engine since they only were made that year.  So ... something doesn't fit here.  My brain is tired.

Stampie

[Stampie]

Just to compare here the total sample VIN given for a 70 Coupe De Ville is J0100001 with J being sales code for Coupe De Ville 0 being the year and 100001 being the broadcast number.

Stampie

PS "The Vehicle Identification Number, less the sales code letter, is also located on the rear upper portion of the cylinder block behind the intake manifold, and on the left side of the transmission"  from the 70 manual.

PSS You can thank me later for totally confusing your issue even more.

[Big Fins]

Unless you are sure of the proper #'s on the block and heads, you could be dealing with a piecework engine. This may not be bad, but damn frustrating when you go out parts hunting.

Fins

[Geert-Jan]

Hey guys,

Omg what did I unleash! 
About the numbers: I'm absolutely positive they are correct. From the caddyshack http://www.geocities.com/MotorCity/Pit/9364/guide/Engineid.html site from Wayne Carroll I know that the 68 through 70 engines don't have a VIN-number. From 71 on the engines had the 61 (62, etc) codes with Q (Detroit) or E (Linden NJ). And yes Michael, in my 68 shop manual also the famous "where-you-can-find-the-VIN-number-on-the-block" line is mentioned but the only numbers I can find are the engine block casting number and the mysterious serial number.

It's not a 75 or a 76 engine because they are electronic fuel injected (E.F.I.) and mine isn't. See http://www.butlers-a1.com/caddim.htm

Last year I wrote the previous owner in Mission Hills (I got the California DMV registration card when I bought the DeVille) a letter with some curious to know questions (mostly history) but no answer....

To convince you guys the head number is right another picture enclosed. And who's causing all the "trouble" (The Gran' Ol' Lady does, I don't )...

Best regards,

Geert-Jan

[Big Fins]

"It's not a 75 or a 76 engine because they are electronic fuel injected (E.F.I.) and mine isn't. See http://www.butlers-a1.com/caddim.htm"

Wrong answer. These engines are both...carbureted and TBI injected. EFI wasn't introduced until 1977 on the 425 in the Fleetwood.

Fins

[STDog]

The engine block casting number is 1485200
The head casting numbers are 1497902

For sure sounds like a 71-73 engine.

The serial number as you can tell is a real mess. I've never personally seen it on an engine.

Really need to check the pistons. Do you have access to a bore scope?
You can check the stroke too to see if it's a 500. Just use a coat hanger in the #1 spark plug hole. Use the timing mar on the rank pulley to find TDC and BDC(180*= half a turn).

Do you have a picture of the intake? does it have an EGR valve (or a place for it)? The choke changed between 70 and 72, and that may help. Of course either or both could have been changed (like the carb).

I Think it looks like 66Q, but is that on the block?
Looks like a cast in number not stamped. Is that right?

This may not be bad, but damn frustrating when you go out parts hunting.

Depends on what parts your after.
If it has 902 heads, the there's no real difference in them and the 250 and 950 heads. All 3 would interchange and even be fine with one of each, unless the A.I.R. system is functional (usually isn't) then you need to not use the 950 heads (which are rare, one year only) or disconnect the A.I.R. and block hole in the old head.

If you need a piston, you know which one, since the head will be off to get the piston out. Only affect the compression, but you don't want one 10:1 piston and seven 8.5:1 pistons (or vice versa). A mix of 10 and 10.5:1 pistons would not be as bad, though still not good.


Nothing else is different.

[STDog]

From 71 on the engines had the 61 (62, etc) codes with Q (Detroit) or E (Linden NJ). And yes Michael, in my 68 shop manual also the famous "where-you-can-find-the-VIN-number-on-the-block" line is mentioned but the only numbers I can find are the engine block casting number and the mysterious serial number.

Sounds like a '76 block then.
But those are 76cc heads from a '71-'73.

Now I'd really suggest getting a look into the cylinder with a bore scope. See what pistons you have.

It may be a real cobbled together job; a 76 block, a 472 crank (68-74) and 71-73 pistons.

Could even be a 500 (need the crank casting number or the stroke measured to know).

I know it's not a 76 short block and 76cc heads. You wouldn't be able to find gas that wouldn't know so bad you break the Pistons.
It's be about 13:1 compression!

[GREG]

EFI WAS STANDARD ON SEVILLE 75, 76, 77, 78, 79....... OPTIONAL ON OTHER MODELS LATE 75, 76, 77, 78, 79.
         GREG

[Geert-Jan]

"It's not a 75 or a 76 engine because they are electronic fuel injected (E.F.I.) and mine isn't. See http://www.butlers-a1.com/caddim.htm"

Wrong answer. These engines are both...carbureted and TBI injected. EFI wasn't introduced until 1977 on the 425 in the Fleetwood

Hi Big Fins,

Hhmmmm... What do you mean with "these engines"? Engines from both years 1975 and 1976? Or the 472 and 500 cid? And can you tell Mr. Butler that his sceme is not correct and Steve Preston that he doesn't have an 1976 Eldo convertible with EFI? http://home.mindspring.com/~76ldo/id8.html . Or is it more complicated? What I meant to say is that my Caddy-engine is just carburated, so no electronic fuel metering (injection) like throttle body (TBI) or EFI or whatsoever. In fact TBI is also an EFI-system... (but now I'm getting off subject)

I know from medical science that TBI also stands for Traumatic Brain Injury.... (this is really off-subject)

Best regards and always willing to learn,

Geert-Jan

[Geert-Jan]

Okay, I took a good zoom-in look on the 3.2 MB picture and I can see indeed a difference between the first "0" (more square) and the second "0" (more oval). The first is probably a Q (with the dash) and the second a zero. See zoom-in pictures enclosed.

Does this help, that the serial number stamped in (not casted as I stated before) on the engine is 66Q192082?

Best regards,

Geert-Jan

[Lars Kneller 8246]

Port (not TBI) EFI was an option on the 500's in 75 and 76, and on all 425's in 77.  You could only get a carb on a 78 Eldo, but EFI was optional on all the other 425's in 78 and 79

[Stampie]

Correct and most 75 and 76 came with a carb.

Stampie

PS - If the better half lets me I'll go clean up the pad on the engine mentioned before.  I was told it's a 76 and haven't seen anything to point elsewhere.

[homeonprunehill]

Okay, I took a good zoom-in look on the 3.2 MB picture and I can see indeed a difference between the first "0" (more square) and the second "0" (more oval). The first is probably a Q (with the dash) and the second a zero. See zoom-in pictures enclosed.

Does this help, that the serial number stamped in (not casted as I stated before) on the engine is 66Q192082?

Best regards,

Geert-Jan

01-04-08
Geert-JAN
You wstate in your post that the number "66Q192082" is on the engine. Where?? I(f you can get to it, I suggest removing more paint, and posting the number(s) again. Good luck,JIM

[Stampie]

This is a copy of my post that he refers to and the picture.

Here is the picture of a later block.  The yellow is the block part number.  The red is where the serial number should be.  As you can see the block must be very clean to even get a hint of the number.  I rubbed that one with my finger and still cannot see it.

Stampie

[Geert-Jan]

You wstate in your post that the number "66Q192082" is on the engine. Where?? I(f you can get to it, I suggest removing more paint, and posting the number(s) again. Good luck,JIM

Jim, in the red section of Michael's post above....

For your convenience a have the original picture enclosed.

Of any help?