Engine Swap...What is needed?

[andycook]

I recently purchased a 2.7 w/CIS to put into my 78 SC, which originally had a 3.0 w/CIS. What do I need to change as far as electrical or any other items to make this work? Thanks in advance.
And for those who are about to flame about swapping engines...when it comes down to being able to drive my car, or watch it sit in the garage, I choose to drive it (I Hope). Hence, a repower.

[chuckw951]

One place to start would be to get electrical diagrams for the 78 car and 74-77 motor. I think the 14 pin connections are slightly different.

I think you need to think in terms of systems where the motor "intersects" with the car:

engine electrical
oil cooling
trans/clutch/shifter
gauges
fuel lines
engine mounting
cooling tin
heating system

I think with most of these systems everything should bolt up or plug in just fine, but probably worthing thinking about these areas and double checking. Perhaps you should look at posts where folks have transplanted an 911SC motor into a 2.7 car and to see which modifications were made and work backwards if that makes sense.

[MotoSook]

Andy, what happened to your 3.0?

The fuel connection might not be exact, but you should be able to make it work. The 77+ cars used a 3-connection fuel accumulator, which you 2.7 might not. If there is no provision for a fuel connection from the 2.7 tot he fuel accumulator you have now (78SC), just get a 76 fuel acumulator.

The 2.7 harness at the rear should have 3 wires to the start...on of them (yellow I believe) should be the cold start.

The tach connection will have to be worked out.

Here is a 14-pin harness key:



the tach signal from the CDI will have to tap into the purple and black wire. I have never talked to anyone who has taken the signal from a 3-pin CDI box to the SC harness/tach, so tinker with it.

Let us know how it turns out.

Good luck.

[MotoSook]

All the hardware, tin, engine mount and such should not be a problem (~same). Just get the fuel connections and wiring right and you should be good to go.

I would suggest taking as much crap off the 2.7 as you can/want to before you put it in. Clean everythign up before you install it. I would take the CIS off and remove the shroud. There is bound to be a mess under it. Give the engine a chance at good cooling.

[andycook]

Thanks guys. Souk, did you pull that diagram out of your hat or what? That is awesome. Thanks you so much. I am going to try and swap the CDI boxes completely. So should I try to find an accumilator while I am at it?
My 3.0 had spun a rod. My schedule just didn't allow the time for doing my own complete rebuild, and my wallet didn't allow me to have it done for me. SO, I opted to repower with this engine.
Beiong my "first" (certainly not last) 911, it will never be sold anyways. It is totally for my enjoyment. So a retrofit in my eyes was not a catostrophic idea. Besides, who knows what else may lie in the plans for my car!! After I get my second one of course.... Thanks again for all your help with this.

[MotoSook]

Andy,

The key was posted by some else sometime back..so I can't take credit.

You will have to change out the CDI box. The 5 pin will not work with the 2.7.

I may have the accumulator from my old 2.7 if you don't want to buy a new one, although I would just go a head and do it. It's not that expensive. I have to rummage through my basement for some other parts this weekend, so I'll let you know if I find it...you pay for shipping and it's your's.

[andycook]

Souk,
Let me know if you have one. I will take it. About time I started collecting parts anyways!! ) Thanks again.
Andy