3.6 longblock possibilities

[Shuie]

I’ve read many posts on this site about 3.6 swaps being done on earlier cars. Outside of building a full race engine or buying a 930, this sounds like the most straightforward way to get 270-290 reliable hp out of our cars.

Has anyone here ever built an engine up using a 3.6 longblock (stock P&C's) as the starting point? Is there a decent carb/cam setup that could be used on a 3.6 that would yield similar or better performance than a direct 3.6 swap from a later car, or is the 3.6 optimized from the factory? What are some options using a 3.6 longblock as the base for an engine build while keeping the stock P&Cs? Furthermore, is this hopeless with a 915?

I know I’m going to do an engine rebuild in the future. I’m still reading, pricing parts, re-reading, and trying to weigh the pros and cons of every engine configuration that I can find. I haven’t seen a carb/cam 3.6 setup yet and am wondering if anyone has tried this? What are the limitations?

[1fastredsc]

You can get carbs for a 3.6, but i don't remember which ones that are. Any 911 motor with the aluminum block has limitless potential, and as far as the setup, it depends on which long block you have. With a 964 motor i believe the cams can definitely be upgraded a bit, the 993 i know nothing about. But one can assume that with any factory 911 motor with street purpose, there's always room for improvement due to conservative cams, compression, ignition timing, exhaust flow (actually this one is held back because of the smog nazis). But i'm sure more knowledge will chime in shortly.

[Bill Verburg]

A stock 964 or 993 has a lot of potential that can be realized w/ just a cam change. i.e. install some 993ss cams, clean up the ports, install a custom chip and you have an honest and easy 280 or so to the rear wheels, and a nice broad torque band. Stick w/ the Motronic for civilized behavior at all times.

Each type has it's own set of advantages as a starting point.

964
advantages- wide range of valves available, good cam drives
disadvantages - barn door MFI, smallish stock ports/valves, external harmonic balancer


993
advantages- bigger ports/valves oem, hot wire MAF, stronger bottom end, lighter valve train components
disadvantages- limited selection of valves mostly factory($$$), cam drive needs to be retrofitted to 964 style

to go beyond that you will need to change to carbs(IMHO a bad idea) or Motec type w/ individual throttle bodies($$$) when you get to RSR type power levels you no longer have a streetable engine.

I would take it down to the crank and do the rod bolts as well as the valve train components.

Believe me a mildly breathed on 3.6 is a very entertaining package !

[ChrisBennet]

Originally posted by Bill Verburg
[BEach type has it's own set of advantages as a starting point.

964
advantages- wide range of valves available, good cam drives
disadvantages - barn door MFI, smallish stock ports/valves, external harmonic balancer

993
advantages- bigger ports/valves oem, hot wire MAF, stronger bottom end, lighter valve train components
[/B]

I thought the 964 had a stronger bottom end with it's solid crank vs the hollow 993 crank?
-Chris

[Bill Verburg]

The 993 crank is a stouter piece than a 964, it was a total redesign including thicker flanges(more rigid), smaller crankpin width(less friction, lighter rods), greater total weight(but in the necessary places). So the crank is 1 kg heavier but more rigid, and the entire rotating mass has been reduced. Other changes to the valve train reduced the mass of those components as well. The result is an engine that revs more freely and is as or more durable.

[Wayne 962]

The trouble is your fuel system. You would really need to go with something like a TEC-3 or Motronic if you made any changes. Going to carbs would sortof be like going backwards on these cars, and I don't think the carbs / manifolds' costs are worth it.

-Wayne

[Shuie]

Thanks guys.

Is there a set of readily available manifolds that will fit a set of PMO's or webers to the 3.6, or are custom manifolds the only way? What about the throttle linkage?

I'll accept that carbs would be a step backwards from the factory. I thought it would be easier to go from a longblock to carbs than to try to find a factory fuel system though. The motivation for carbs is that I dont have the tools or the knowledge to mess with DME's, fuel mappings, etc. If I found a complete 3.6 at a good price I wouldnt pull the factory fuel system for carbs.

If I want a carb/cam setup should I just start with a 3.2 or a 3.0 longblock, or can I do something better with a 3.6 as a base?

Keep the advice coming, I need all the help I can get


edited to say the following:

I just checked the PMO website. It looks like they offer the manifolds, linkage, etc that would be needed to put a set of carbs on the longblock. Price of the carbs + longblock is close to (if not more than) a complete 993 engine with DME. Wayne your right, its probably not worth the cost.

Thanks again for the help guys