I started out with this on the 964/993 forum but I think they are all asleep over there!
Let's see if real engine builders are a bit livelier
A partly dismantled, mostly complete 1992 3.6 964 engine (type M64/01) has found its way into my garage and is about to become my next project.
I have modified and rebuilt several 3.2s and 3.3 turbos (engines and cars) but the 3.6 is new to me so I am looking for some ideas for modifying it. So far, I’m comforted by the fact that the engine itself is pretty much the same as earlier models, but where I am in new territory is with engine management, intake and fuel systems.
At present, I haven't decided what car it will end up in - that's next year's project, but I am considering a 914 (lot's of work and a bit of a challenge) or a nice mid 80's Carrera (more likely, and obviously much easier).
My aim at present is to rebuild this engine with a bit more power than standard (of course!) so that it will be suitable for street use and occasional club events. That means no over-the-top internal mods, but I am prepared to look at engine management, EFI and headers.
I am looking for ideas or best-practice directions in the following areas …
Heads
Ports look reasonably large. Is there much to be gained by porting them? This is a zero cost item because I always do this myself.
I took the heads off last night and was surprised to see that they were installed directly onto the barrels without gaskets (just like previous models). I thought there were some issues with heads on these early 964 engines leaking and it was fixed with gaskets. Maybe I wasn’t paying attention that day! Should I be looking at doing anything more than lightly remachining the head and barrel faces?
Camshafts
Which camshafts are practical alternatives to the standard 964 cams for good road performance?
Inlet manifold and blocks
The size of the phenolic blocks on 930 motors is a real constraint to inlet porting. At least the 964 blocks are larger, but there’s still not much wall thickness available for boring them out larger. What’s the usual way around this?
The manifold itself is a bit of a monstrosity. I have the aluminium version. I am prepared to consider other options if there is a reasonable benefit.
Oil cooler
This engine doesn’t have the crankcase-mounted oil cooler that I am familiar with on earlier engines but the crankcase looks like it could be drilled to accept one. Is this the case? If I fit a cooler here, I guess I would also need to modify the air ducting over the engine as well?
Exhaust
I’m open to suggestions here. I don’t know how effective the standard system is and whether there is much to be gained by using after-market headers. Ideas, opinions?
Clutch
I have the standard 964 flywheel only with its loose starter ring gear; no clutch or pressure plate. What are my options for mating up to a 915 box? Use a 3.2 clutch and flywheel complete?
Engine management and fuel injection
I don't have injectors, ECU or engine harness. A few other intake and fuel injection parts might also be missing, so even if I keep it stock I will need to spend money in that area regardless. Therefore, it might be an option to go to a new EFI system. The twin distributor looks like it has been full of water for a while and may need a bit of work and one of the fuel rails is bent, although most of the fuel hoses look OK.
Therefore, I am prepared to look at other alternatives as far as engine management and fuel injection are concerned. Are there some options that are proven to be easy to set up and tune for this engine?
I could also scrap the ugly inlet manifold and the phenolic blocks and go with ITBs with some kind of injection system. Is this done? I know it is a leap backwards as far as technology goes, but even a couple of Webers might be entertained (look good and sound nice!).
I know there’s lot’s of separate little subjects here, but each time I search on something, I get bogged down for hours reading about all sorts of interesting stuff which doesn’t actually answer my questions. I would really appreciate some responses from others who may have been faced with similar decisions in the past so I can form a general direction for this rebuild and start shopping for parts.
This is how it arrived home (in the back of son's Suzy).
