ENGINE SWAP QUESTIONS – 73.5 2.4 to 81 3.0 (now a 3.2)

[LakeCleElum]

Hoping to attract some of the knowledge experts that might hang out here more than the Tech Forum?

My 73.5 has 122,000 miles and is very original (except for paint color) with Recaro Sport Seats, S trim, etc. The 2.4 runs well, but is showing the dreaded oil pressure issue. After much soul searching, I’m going to keep the 2.4 and install an engine I bought here on Pelican last month. Engine is:

Recently removed upgraded '81 SC engine and transmission from my '81 SC after car was damaged in front, causing parting out the car. Upgrades include 1) Max Moritz 3.2 liter pistons and cylinders, 2) 964 cams, 3) Raceware hardware, balanced rods, Carrera oil pump. New parts included: intake valve sleeves, rod bearings and rods balanced, and rocker arms. Transmission clutch disk, pilot bearing and fork were replaced. All of the above was performed in 2004 at 120,000 miles approx. and now at 132,000 miles. Good solid reliable running engine with no oil leaks. $4,500 for engine.

The engine comes with excellent documentation of the work described. I’m starting to gather parts I will need and have a few specific questions:

1. Can I use the 81 flywheel and clutch with my ’73 915?
2. Can I use my 73.5 fuel tank?
3. Can I use my 73.5 fuel pump and Accumulator? (81 Engine is CIS)
4. Can I use my 73.5 Oil Tank?
5. Engine came only with Jetronic “Brain” for electrics. Can I use 73.5 coil?
6. Should I find a 1981 CDI or go with MSD?
7. Can I use my 73.5 Tach?
8. Can I put my 73.5 oil pressure sending unit into the 81 engine?
9. What is the compression ratio of the 3.2 Max Moritz kit?

From a search here, I think I have the info needed for wiring the 14-pin connector. I will have to add an oil cooler in the front fender if anyone has any tips or available parts….

Thanks in advance…..

[Steve@Rennsport]

Bob,

Some answers:

1) Yes, but I'd install the Sachs Powerclutch for its additional clamping force.
2) Yes.
3) Yes, but its a little shy in delivery volume. The SC pump is better, however some plumbing mods are needed. I would also remount it up front to eliminate any vapor lock issues (thats why they moved it up there). The early accumulator is fine.
4) Yes.
5) Yes, if you use the Bosch 3.0 CDI.
6) I would use an MSD 6AL and matching High Vibration coil.
7) Yes, with the MSD: no, with the Bosch SC CDI.
8) Yes.
9) About 9.7:1.

[LakeCleElum]

Steve - You have been a huge help. Thank you very much. Really appreciated....