rs motor verification

[bmarchet]

i currently have a 1970 T but i am very close to buying a rs replica built on a 72 tub. trouble is, although i am pretty familiar with the reg 2.2 motor i have, i don't know anthing about the 2.7 rs. the owner claims (and i have no reason to think he's lying) that it's a real stock rs motor. he has an engine case number that i don't know how to verify. how can i tell for sure it's a real rs motor? the info is Engine type – 911/83 – 2.7 liter · “RS” Race case - #783873.

can anyone make sense of this? and where on the case can i find these numbers to verify that's what is actually in the car?

thank you very much.

brian

[nick-moss]

I would be very suspicious. How many 2.7 MFI motors made it to the US?
The engine code is correct.
The serial number should be 663****, 664****, 665****, 6668*** depending on the production year (73, 74, 75 or 76)

That 783873 number is odd. It should be 7 digits. If it was 6783873 it would be a '78 911 Turbo motor.

[bmarchet]

thank you very much,

apart from the serial numbers (which i will do my best to verify), are there other obvious signs that will make an rs motor easy to identify?

thanks.
brian

[nick-moss]

It should have magnesium cases, which are dull grey, mechanical fuel infection, red engine shroud, and should look like this



The engine number is the real identifier, but if someone wants to fake one extenally it's not too difficult.

[bmarchet]

thanks a lot nick. i really appreciate your insights... i have noted the engine numbers in your reply. where are they located? in the regular place?

thanks, again.

brian

[nick-moss]

Engine number vertically on left, engine ID horizontally to the right

[bmarchet]

thanks again!

[ChrisBennet]

I don't have a picture of it, but don't RS motors have some sort of plastic piece to the left and above the fan?
-Chris

[Tim Walsh]

Nick,
Is that an RS motor? It's got the oil pressure sender in the front. It's definitly an nice MFI motor though

Chirs,
Yes they did but so did 72 and 73 T,E and S motors. I have the warm up housing on my car

[nick-moss]

Tim

My motor is NOT an RS motor, the number is 6650375, making it a '75 MY 2.7 Carrera MFI motor.

But it would be easy to fake it as a genuine RS motor, after all all the engine numbers are freely available on many different sites and books.

I still can't answer the question as to how to genuinely verify an RS motor.

[Tim Walsh]

AHHH ok that explains the different pressure sender.

I don't think there's any ABSOLUTE way of saying yes or no to the RS authenticity. The ony real way would be to have a complete list of every single RS motor and then you could track forgeries but even that has loopholes. In essense there really isn't a perfect way but the motor ID # is probably the best way in my opinion

[nick-moss]

Tim

What is the significance of the oil sender?

[Tim Walsh]

The oil sender on 73's are near the flywheel on top of the block just above the oil cooler. Evidently on later cars it was moved to the right cam line

[nick-moss]

I have a 70 2.2 E with senders in both postions, as has the 2.7 pictured above. One is a pressure switch, one a sender

[studeb]

The engine pictured has pressure fed tensioners. The cam lines are shorter on the right side, which i believe force you to mount the pressure sender at the fan end to fill the missing length.

[Tim Walsh]

ahh I stand corrected.. I haven't seen any early cars with the sender up front except for the 73.5 T.. [Shrug] You learn something everyday.