drola

I have a 1995 obd1 engine that I want to put into my 964 and was wondering if anyone here has already done this. I have the complete engine, ecu and harness out of the donor car. I also have the 964 engine that I can take parts from to make the swap easier.
I have some questions about this swap:

1) Just from initial observations, I see the fuel rails are different. The 993 motor has the fpr on the back of the bank 1 fuel rail, which my 964 does not. Logic would tell me this is the return line. Being that the line going back to the tank on the 964 would be different, should I remove the line from the donor car? Or is there another way to deal with this?

2) The harness plugs that go into the left side panel in the engine compartment - one plus goes into the 993 ecu harness, but the second plug is completely different. It goes into the body harness and into the car from the right side. Does someone make an adapter for this? Or do I need to figure out all the pins and proceed accordingly?

3) The secondary air injection system - do I just remove it and plug up all the ports? Any programming that needs to be done here to cancel it out?

4) Breather hoses I can figure out

5) Cruise control - I haven't looked into it but the plug looks the same as the 964. I'll compare them to make sure.

6) No drive block so all good there

7) Oil lines are easy to figure out

8) Exhaust will be swapped from 964 since the 993 motor has 4 stud holes in the heads - I can just relocate the studs to match the headers

Any other suggestions are greatly appreciated.

Moriartyhlms

I’ve done this, see my engine build thread from 2016. If you have the 993 obd1 harness and ECU, that makes thing a lot easier.
1) The 993 fuel rails are a lot simpler than the 964 ones and shouldn’t require many mods on the engine bay side, but check carefully that those old lines aren’t leaking.
2) you’ll have to look at the wiring diagrams to check all this. A lot of the 964 wiring is the same as 993, but not all of it
3) just plug the ports. I think Patrick Motorsports might have a kit for deleting this.
7) I think the 993 oil input line might have a different style than the 964 to fit around the 2nd oil filter on the 993.

Tarek307

I owned a 964 for almost a year that had a 993 engine in it, daily drove it, but it always didn't feel like a proper "964" to me, it was almost too smooth...but yes it does work and there were no mechanical issues with it.

drola

Thanks for the responses.
I've been looking carefully at the wiring diagrams for both cars and pretty sure I got it down. My concern was the body harness but from what I see it shouldn't be a big deal to get them to work.
The oil lines will be tackled with both motors out of the car. Looks like I can use the 964 line that goes around the back of the engine (actually the front) as I will use the headers off the 964 so routing that line should not be an issue since the 993 exhaust will not be used. The only line I will need to work on will be the one under the oil filter on the engine. The 964 has a threaded inlet and the 993 does not. I'll figure something out there.
I get the 993 engine is smoother than the 964 and may possibly take some of the visceral feeling out of it. But I do plan on spicing it up a bit with some SS cams, larger throttle body, headers, lwfw and tune. So hopefully it will be fun. My 964 is about 400lbs lighter than stock so fun factor should be high.

budge96

I have considered doing this a few times I was meaning to comment earlier on but will do so now , with the entire 993 harness and the fuse box you shouldn’t encounter any issues if you need to adapt the 964 rear fuse box some wiring changes may need to be addressed ..
that’s about all I have …with the change in harnesses and box the upgraded injection install should be straight forward , I would also try and run the 993 exhaust at least a ‘95
that would allow one O2 sensor…Bert