Mystery Motor

[spitfireal]

Hello All,

I took down a motor serial # of 6403681 from an engine in a 1977 911. I'm confident the motor is not original. Can anyone decode this number?

Is it a valid number or is it possible I wrote it down incorrectly?

Thanks,
Allan

[vanwyk4257]

According to my book, there were no 6400000 prefix 2.7motors in 1977. I'm guessing either you wrote the number down wrong, or you may have a '79 3.0 SC motor, which started with engine serial numbers in the 6390001 range on up. I would check on the right-hand side of the crankcase at the base of the fan housing, I believe that's where the engine type code is located, I'm sure someone will correct me if I'm mistaken. Good luck sorting it out.

[Rot 911]

The first two digits "64" are probably correct, but I am not finding any year where the third digit of the engine number is "0"

[vanwyk4257]

Kurt, that's why I'm thinking perhaps a '79SC 3.0. There may have been enough production on these to reach the 640---- range.

[Rot 911]

Originally posted by vanwyk4257
Kurt, that's why I'm thinking perhaps a '79SC 3.0. There may have been enough production on these to reach the 640---- range.

Good point, but from looking at the Red Book Porsche apparently never allowed the third digit to be a "0" regardless of the number of engines made. Now if the third digit was misread and is actually a "D" then we have a 1983 SC engine.

[spitfireal]

Thanks for the quick reply guys! I was told it was an 1980 3.0 motor but I was expecting to see an A in the code for that. The number was taken from the stamping on the right side of the block beside the fan.

Thanks again,
Allan

[CliffBrown]

Allan

I think you have a 1970 2.0 originally used in the 914-6. The serial number should be stamped on the area around the thermostat not next to the fan. Type number is 901/38 I think and also stamped near the serial number.

I have one in stock also.

[RickM]

OK, now I'm curious as to which engine this is....We need pics!

[Early_S_Man]

Unfortunately ... PAG did allow the third digit to be zero in both 1970 AND 1980 911 engines ... causing quite a bit of confusion, and requiring that the engine type number be used to clarify the situation.

The 1970 engines used a Mg case, and the 1980 engines used Al ... but not everyone is confident differentiating between the two metals.

[spitfireal]

Thanks again to all for the great responses!

Unfortunately I won't be able to get a look at the number again until Sunday night but I was fairly confident I wrote it down correctly at the time.

According to Early S Man it may still be an '80 motor as described to us which is encouraging. I've attached a picture as requested by Rick M. I don't know if it will be clear enough to be conclusive about anything.

FYI this '77 has also had a 993 body kit installed...

Thanks,
Allan

[emcon5]

According to my cheat sheet, that number is a US/Canada market 1980 911 SC.



Tom

[spitfireal]

Thanks Emcon5!

That's a great reference sheet you have. Can you divulge its source?

Thanks again,
Allan

[Joeaksa]

Allen,

If you put your mouse over the photo that Tom posted, then hit the right click and "save picture as" to somewhere on your hard drive, the source can be at hand anytime you need it!

JoeA

[spitfireal]

Thanks Joe, I've already done that!

I was thinking this sheet looks like part of a larger document which may list all of the model years and numbers. (Only 1978 to 83 on this one page). It would be a great resource to have!

[CliffBrown]

Looks like that particular serial number is for an SC but some data out there also shows the 640XXXX is also used on the 914-6.

The following data will not show-up very well here but shows the numbers for a 914-6, I'll include the website link (subject to credibility)

http://www.porschedecals.com/history914w.htm

Porsche 914/6 Serial Numbers
Year Model HP
DIN
@RPM Chassis
VIN Engine
VIN Transmission
VIN
1970 914/6 110 @ 5800 914 043 0011-
914 043 2668 901/36
901/37
901/38
901/39 640 0001- 640 0889
640 3001- 640 4000
640 4001- 640 5781
640 7001- 640 8000 914/01
914/05 750 0001-(5 speed)
780 0001-(Sportomatic)
1971 914/6 110 @ 5800 914 143 0011-
914 143 0443 901/36
901/37
901/38
901/39 641 0001- 641 0268
641 3001- 641 4000
641 4001- 641 0163
641 7001- 641 8000 914/01
914/05 751 0001-(5 speed)
761 0001-(Sportomatic)
1972 914/6 110 @ 5800 914 243 0011-
914 243 0260 901/38 642 0001- 642 0270 914/01 752 0001-(5 speed)

[Early_S_Man]

Cliff,

Your information is correct about the 914/6 engine numbers ... however the serial number and engine type number on those engines is on the top side of the case near the center ribs, not alongside the fan support.

An engine type number of 930/07 will confirm that the engine in question is a 1980 3.0 SC engine for the USA/Cdn market.

[CliffBrown]

Warren

You're absolutely right, the fact that Allan's motor has the serial numbers on the fan support and not next to the thermostat is the clue I overlooked in his first post. Then when we saw the photo it really became obvious.

I have a 914-6 case in stock and recognized the number from my inventory sheets.

Interesting that Porsche would use the same serial number on two completely different motors, even ten years apart.

[emcon5]

Originally posted by spitfireal
Can you divulge its source?

I can neither confirm nor deny that it may or may not have come from The parts software that must not be named.

I have the engine numbers through 89, as well as chassis number info, and some other stuff, like scans of some of the factory tech bulletins, and some magazine articles here:

http://members.rennlist.com/emcon5/

Tom

[spitfireal]

Nice work Tom! I've bookmarked you.

Thanks again,
Allan

[sammyg2]

When I get home from work, the first thing I do is PET my dog

I understand the software that shall not be named is actually available for purchase now, and therefore legal?