78’ 911 3.0 conversion to 3.4-5L questions/thread

[Tylermelvin]

If I can’t sell my recently rebuilt trans, clutch, rear diff, and gasket/hose/pipe refitted 78 911 for what it’s well worth I’m keeping it, but I’ll need to know specs on a euro performance rebuild for when the motor needs it.

Can I get proper parts lists and performance theories from everyone please.

[Mixed76]

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[75 911s]

Hey Tyler.

You've covered a broad scope of motors. I recommend searching for specific builds and reading threads. There are a few "parts lists" floating around, but each motor can get pretty specific. There are several great threads here that include parts and specifics, but it's depending on build. Your 78 3.0 is perfect for a 3.2 Short Stroke motor. 3.2 motors (so 3.4 and 3.5) come up fairly often on the classifieds. Again, there are great build threads focusing on those displacements.

I also recommend Bruce Anderson's 911 performance book and Dempsey's how to rebuild books. These are good resources for what it takes to rebuild a motor. Maybe you wont rebuild it, but the more you know, the more informed your choices can be.

Good luck!

[Bill Verburg]

Originally Posted by Tylermelvin

If I can’t sell my recently rebuilt trans, clutch, rear diff, and gasket/hose/pipe refitted 78 911 for what it’s well worth I’m keeping it, but I’ll need to know specs on a euro performance rebuild for when the motor needs it.

Can I get proper parts lists and performance theories from everyone please.

If you keep the stock 70.4mm strock SC crank you can use 95mm bore p/c for 2994cc, or 97mm p/c for 3121cc, or 98mm p/c for 3186cc, cr between 8.5 & 10:1 the higher the more likely you will want twin plug

w/ a 74.4mm Carrera crank 95mm p/c gives you3164cc, 98mm p/c gives 3367cc & 100mm p/c gives 3506cc, but the bigger the p/c the less stable the cylinders become because the bases get very thin, I'd avoid 100s on a 3 or 3.2 case

the 3.6 used a wider stud spacing, 90mm vs 3/3.2/3.3 86mm spacing and so can use bigger bores

w/ 76.4mm crank 100mm p/c gives you 3600cc, 102mm gives 3746 & 104 gives 3894

all in all a 993 swap is a lot of bang for the buck and ought to be considered

[Geronimo]

A 993 swap is what $30K give or take, for almost 300HP. :|

$14k-18k for a use engine, plus a future rebuild $15K Plus all the bits needed to complete the swap.