dumn question: Matching chassis & engine numbers?
 

I tried the search to try and find the answer, but to no avail, so....

I am looking at a US-spec '83 SC coupe with VIN WPOAA0918DS122336 and engine number 64D4553. Although these check out as '83 production numbers, I assume that since 2336 does not equal 4553 that this is not a numbers matching car, and has had its engine replaced. Am I correct?

You need to contact the PCA and get a COA.....takes 3=4 weeks and confirm if the engine is original or not.....BTW, costs a few bucks. may not be worth it....

I would say No

I have my original dealer warranty book / voucher with my 83 cab and in it it has the last four of my vin are 0853 and my motor # is 64D4168. These coincide with the motor that is actually in the car..

The way I understand it these are not like the old GM muscle cars where the vin was stamped on the engine block.

Also see post #5 in this thread it might save you some money.. You might try to tell them you are looking at purchasing car 83 SC Vin# ??????? with engine # ???????. Is this motor the original to the car?
worth a try.

http://forums.pelicanparts.com/porsche-911-technical-forum/507099-1983-911sc-wide-body-factory-authentication-needed.html

I am sure someone much smarter than me will chime in..

Gregg

Engine and chassis numbers are not the same in Porsches.
I think that when someone says matching numbers car, it refers that the engine number and chassis number match the numbers in the original Porsche invoice.

Thanks for the clarification everyone.

You have to realize that the USA targa, cab and coupe all have different vins but will all carry the next available engine for the car,
You might have 3 body styles, 500 units and the next numbered engine will be 64D0501

Bruce

Matching numbers car does not mean the engine # and VIN are the same for most manufacturers. What it means is that the engine # and VIN are what were put in the car new and factory records verify. My old Aston Martin DB4 had a VIN of DB4438L (L for left hand drive). The engine # was 370/484 (370=3.7 liter engine). The buy (the Prime Minister of Kuwait) has his boy verify this with Aston Martin. Too many test engines/ replacement engines from the factory to have everything match exactly.

Forza,
Unless the seller has already purchased a COA on the car there is really no way to know if it's original or not. Given how durable the 3.0 911sc engines are, the likelihood that the engine is original to the car is high. However, it's not something I would be overly concerned about. It's probably another decade or two before anyone starts to care about numbers matching 911scs. Porsche just made too many of them. It's not like a '68 911s or an RS. It's just a 911sc. If the car is solid and the price is right buy it. If you are looking at concours examples and determined to stay numbers matching, you'll find a car with complete records from day 1 and a COA, but you'll pay a 20-40% premium in price over your run of the mill driver.

This might speed up the process, its from the German "elferhelfer" site.

Fahrzeugidentifikation 911 1978-83 Porsche 911 SC

US models are marked red

Here is what I would suggest....I did the same kind of "check" for my 85 and it seems to make sense. Perfectly accurate?...no...but bear with me.

From my Tech Spec books.....the last digits chassis number RANGE for your car is 120001 to 125000.

From the same source....the last digits engine number RANGE is 64D0001 to 64D9999

So, here's my thought. There is not necessarily a 1:1 relationship as to the sequential use of motor matched with sequential use of chassis.....but if your chassis is 2336....that is about half-way thru the production year run. Little under the half way point. About 46%-47% of the way thru the production sequence ( 1-5000 )

As for the engine....your number of 4553 is likewise about half-way thru its own number sequence. Again, a little under the half way point., about 45-46% through its own sequence ( 1-9999 )

My vote?....makes convincing "sense" where they "fit" in their respective range.

I did the same kind of analysis for my 85, and convinced myself it was the original engine for the chassis too... for the same reason.

FWIW, which is more to me that others in this case, the COA arrived and everything does in fact match up.

What did I tell ya?.... the engine sequence along the model years' time line.... was very close to the chassis sequence along its own timeline, as I had suggested.