Engine numbers

[marlun06]

Hello!

I have a 911 Targa -76. I can´t get my numbers on the Engine and chassis to match.

On the Engine it says, AT 6150766. When i look i lists this is an 2,7L 110kw engine from -75 with enginecode 911.41.

I thought it was an 2,7L 121kw Engine from -76 with enginecode 911.81!

My chassis number is 911 63 11 021. When i look in lists this is an 2,7L 121kw with enginecode 911.81, exactly what i thought I had!

I´m rebuilding the Engine and thought that if it´s an Engine from -75 then I need to make the oilbypass modification. BUT when I split the Engine I notice that the modification is made by the factory (no hole or plug in the side of the oilpassage! The block is casted from the beginning with this modification). This means to me that the Engine is a mid or late -76 beacause this modification began to be made by the factory in mid -76!

Can anyone help me to figure out what kind of Engine I
have???

It has the Bosch K-Jetronic fuelinjection system!

Marcus

[Glenfield]

I presume you’ve seen this: Porsche Engine Code Resource. Does suggest you have the 911.41 engine.

Your VIN # does appear to check out with the 121kw targa (https://www.stuttcars.com/technical/vin-decoder/). Have seen examples of cars sold early in a given year and listed for that year, but really a late production run from prior year. Haven’t seen cars with VINs from one year and an engine from the prior though but doubtless others can weigh in

[nathanbs]

What engine type does your engine have stamped on it? What’s the “AT” that you wrote before you engine serial number?

[marlun06]

Have one suggestion that ”AT” stands for Austach in german. Austach means exchange/replaced, I think.
Could it be that they changed the right half of the engine case? Must have happened between -76 and -84 in that case, before it came to Sweden, imported from Germany. I know all the Swedish owners and they all say it didn’t happen when they owned it! Perhapes a guarantee case of they bother to stamp ”AT” in the enginecase? Don’t think a home mechanic would do that?

Thanks for the links and answers👍

[djpateman]

The AT basically says you have a factory rebuilt motor. It would likely have all the upgrades that were normal practise on the date it was rebuilt. Quite likely a new case. As to why the year and type do not match is not known. After all these years it is probable that the engine came from another car.