3.6L Engine Swap : 964 vs 993......

[Goldmember]

So I am preparing to buy a 3.6L to swap into my 1980 SC.

A friend might have a 964 engine for me.. Some people have said that the 964 engines are stronger, but perhaps less powerful than the 993 3.6L's....

Any input is appreciated.

[Bill Verburg]

Originally Posted by Goldmember

So I am preparing to buy a 3.6L to swap into my 1980 SC.

A friend might have a 964 engine for me.. Some people have said that the 964 engines are stronger, but perhaps less powerful than the 993 3.6L's....

Any input is appreciated.

There are Pros and Cons to each, I've had 1 964 and 2 different 993s in my '76
the 964 crank though needing a vibration damper has bigger bearing surfaces and so is valued by the track set, these cranks were used an all 964 and the 993Cup cars

the top end and engine management of the 993s is a big improvement on the 964 as long as you stick w/ OBD1 cars('95 US 993, '94-98 RoW n/a 993)

The 993 non v-ram fits the engine compartment better than either a 964 or 993 v-ram, though all can be fitted

'93-94 964 are desirable vs earlier because of several improvements, '95 993 non v-ram is better yet, and a RoW '96 up v-ram probably best of all for street use.

I'd avoid US 96 up because of OBD2 issues

[saxen]

Sub"d

[johnsjmc]

A big part of the horsepower difference between the 964 and 993 is because of the improved HEs on the 993. Many people use the 993 HEs (with flipped flanges on one side ) on the street .That exhaust probably brings the 964 very close to the 993 power wise. The variorams still offer a broader torque curve though

[Bill Verburg]

Originally Posted by johnsjmc

A big part of the horsepower difference between the 964 and 993 is because of the improved HEs on the 993. Many people use the 993 HEs (with flipped flanges on one side ) on the street .That exhaust probably brings the 964 very close to the 993 power wise. The variorams still offer a broader torque curve though

That and the heads and the ait flow measurement systems and the valves
964
ports 41.5/38
valves 49/42.5 9mm stems
DME 2.10 w/ barn door air measure

993
ports 43/39
valves 49/42.5 w/ 8mm stems
DME 2.20.1 w/ heated element air measure

993 vram RoW
ports 43/39
valves 50/43.5 w/ 8mm stems
DME 2.20.1 w/ heated element air measure

[Jim Dorociak]

993 engine makes more hp and has hyd lifters - so no more valve adjustments. jim

[Canada Kev]

The 993 are a bit quieter mechanically, too, as I understand.

[rbogh901]

Hydraulic lifters may be a disadvantage?

[Canada Kev]

Some change them out to mechanical, but I think that's only those racer types that sustain high RPM running. They might also eat up a little bit of power. I'm just speculating and regurgitating some stuff I think I read somewhere, sometime, so don't take it as gospel.

[Goldmember]

Thanks for the feedback guys.....

There really doesn't seem to be a clear winner. As far as I can tell the the 964 seems to be stronger than the 993's. Crank and rods especially....

While the 964 lacks the desirable plastic manifold and hydraulic lifters, I have heard that with upgraded exhaust and a tune, the 964 power output will be very close to that of a 993.

I'm sure that if I had a line on a good 993 motor, I might be singing that tune, but as it stands now I am looking at a 964 engine for a very handsome price.

[Jack Olsen]

Getting a good engine is probably more important, ultimately, than whether it's a 91-94 or a 95 or an OBDII motor.

[petevb]

It's also good to consider weight as part of this discussion. Weight is quite influenced by the flywheel used, exhaust, etc, but the '95 993 in particular is quite light. That said, the low end torque of the VRam puts it in a different class in my book.

[johnsjmc]

At about 3200 lb curb weight I consider my 993 to be rather portly. That said it is almost as fast as my 1980 SC was with a 3.6

[petevb]

Originally Posted by johnsjmc

At about 3200 lb curb weight I consider my 993 to be rather portly. That said it is almost as fast as my 1980 SC was with a 3.6

I'm talking about the weight of the engine, not the car. Your 993 was portly, but your engine, if it was a 95, was not (in the context of the 964 and 993 VRam motors).