7R cases ??

[RussianBlue]

... yes I did do a search...

Anyhow can I get a simple answer explaing 7R cases?

What years were they made?

Is an early 7R case worth more $$ than a lets say a 74' 7R case? Why?

Is a 7R a 7R regardless of year?

Would a 74 7R cases be frowned upon if used on a historicaly significant 1972S lets say?

Thanks,

alex

[kenikh]

My understanding is that value and correctness does depend on the case. I don't know the ID numbers base on year so can't speak to that, but 'unnumbered' 7R cases are worth the most, since you can pretty much stamp any number onto the case as a result. Soterik mentioned to me that an unstamped 7R case is a correct replacement for RS cars. I can't imagine this kind of case detracting from the value of an S car. I could be wrong, though.

[Scott Clarke]

7R cases were made for late 2.4 and all 2.7 motors. For a 72S, a 2.4 case would be required unless you are increasing displacement to 2.7 or 2.8. Assuming you have the numbers-matching 2.4 case, any other case would detract from the car's value. If the numbers don't match anyway then it won't matter. So, if you are building a 2.7 or 2.8, then a '74 case would be a good choice.
-Scott

[davidppp]

Yes, early 7R will be rarer, and more costly.

They have smaller holes for the cylinder barrels.
And will make anything from 2 to 2.4L.

Most 7R are from 2.7 and well bent..

Kind regards
david

[RussianBlue]

Thanks people, very kind.

Should one assume that all 2.7 7R's are "bent"

AND are they fixable?

Kindly,
alex

[kenikh]

You are most likely to find them 'well used'. That said, I'd imagine that most of these 7R cases can be resized and line bored. It just depends on how much $$$ you want to spend on machining them back to usable shape. I'd be more willing to do it to a 2.4 case than a 2.7 though.

[rswannabe]

Alex,

Keep in mind that while there are some 1972's with 7R cases from the factory, most 1972 911's had the 4R/5R cases.

Not all 7R cases are the same either. First you have the "small bore" 2.4 liter 7R cases with their 92mm spigots. Then you have the standard 2.7 liter 7R cases starting in '74 with the 97mm spigots. Some time in '76 porsched incorporated the oil bypass modification to the production line as well

PM'd you.

Brooke

[Scott Clarke]

Alex-
Most cases can be fixed, but they need to be checked out by someone that knows them well. It's not difficult to get one sorted out. Any quality rebuild with any case will mean some case work anyway. With a 2.7 case the main bearing journlas need to be looked at, and, of course, case savers installed for the head studs. In addition, the cylinder spigots should be trued up, and the oil bypass modification done.

[724doorE]

My 72E chassis number 060 came with a 3R/4R case, so you even had differences throughout the production year.

[buster73]

You can be lucky to find a cheap '73 T basket engine with a 7R case. With the T engine you have a fair chance that the case is not bent (possible though). My early 73.5 T came with a 7R case (number matching with the car).

[76NineEleven]

Hello,

I'm pretty new to all this, even to Pelican, could someone explain what "bent" with respect to a 2.7 motor means?

I have a 76 2.7 that runs very well, leaks a bit of oil, but runs strong.

Thanks for any insight.

[MACHINEMON]

I have a 901 101 102 7r case on a 1975 911s. Where would numbers be that matched the case to the car serial numbers?

[RussianBlue]

[Porsche_monkey]

What are you thinking of building?

[MACHINEMON]

So those numbers would match the car serial number as in 9116930133? Joel

[MACHINEMON]

I am trying to find out what I have. I may post a pic of the car and see if anyone recognizes it.....

[fryardds]

Alex has posted a photo of a real '73 2.8L RSR case.