Building up/modifying a 2.2l engine

[FrayAdjacent911]

What's the most someone has done to a 2.2l out of a ~70 911T?

Build up to E Spec with pistons, cylinders and cams?

Has anyone gone to some sort of electronic fuel injection and electronic ignition combo?

Has anyone turbocharged one of these little monsters?



The reason I'm kinda askin is, one of the guys from Twins Turbo (that has that show on the History channel where they slap some bolt ons on some cars and race them) gets on another forum I frequent, and posted his dyno results from a Supra they built up. (twin turbos, 40psi, putting out about 1070HP and 750ft lb) I asked if he knows if anyone has done anything serious with an older Porsche engine.

It's just curiosity at this point. I'm probably a year or two away from doing anything engine, except possibly chasing down and resolving leaks...

[jluetjen]

Originally posted by FrayAdjacent911
I asked if he knows if anyone has done anything serious with an older Porsche engine.

Sure! It was known as the 930. (I'm only being half sarcastic BTW). When Porsche developed the first 930, they identified a number of issues with blowing the early engines to bigger HP. Off of the top of my head, here are a few...

1) The mag case isn't strong enough. So they came up with an aluminum version.

2) The engine had insufficient cooling, so they installed a larger oil pump (based on the earlier race engine pump) and additional oil cooling in addition to the piston squirters that were already there.

3) The MFI system wasn't designed for the additional fueling requirements of a blown engine. The 935's used a specially modified MFI system while the 934's and the street 930's used the somewhat more "self adjusting" CIS system.

4) The rods and pistons were changed.

5) The porting of the heads was changed to take into account the airflow requirements of a turbo'd engine which are different from a NA engine.

6) The camshafts were changed (but many people find the stock 911SC camshafts an improvement)

7) The brakes were updated with 917 units.

8) The gearbox was replaced with a significantly stronger unit with only 4 gears.

9) Wheels and tires were enlarged.

Porsche did do a "small" 935 known as "Baby" which was very successful in it's few outings. Try checking out this search on "935" and "Baby" for the details. I'm sure that there are more changes then what I mentioned, but it's just too early to look them up.

[silverc4s]

Matt,
John has summed up the main changes very well, so I will not even try to expand that list.
There is another way to look at the performance potential of any engine, and it boils down to two critical factors that will limit yor results, regardless of almost any effort you make:
1. How much horsepower can the heads make?
2. How much horsepower can the bottom end (rods, crank, case) deliver?

The reason that you see these Supras and 300ZX's with such wild HP numbers is that they have the ability to be developed in both these areas. I have seen articles stating that the Supra crank/block assembly is good for 1500hp or so! And the 4 valve, water cooled heads on both these engines probably have actual & potential flow rates well beyond our classic 911 2 valve designs.

The strength & power capabilities of the 911 engine come from things like the 8 main bearing forged crankshaft, excellent 2 valve head design, oil/air cooling that permits a lot of hp to be developed, etc.

It has it'slimitations however...

[jpnovak]

Matt,

There are some high HP versions of the 911 engines. Just search for the "hp junkies". These are usually done to later engines so that extra displacement and the strength of materials work together. John outlined this well.

Bill, adds some great points that you have to think about. The biggest drawback for your 2.2 will be the case. The early mag case is just too week for high HP designs.

If you do a search for Pat Williams Racing you will find some small displacement, high HP motors. I think they run a turbo 2.0L with a nearly 500HP output. These motors are very expensive to build and I would imagine have a short lifetime. Consider lots of machinework, custom intakes, engine management and tons of tuning time as de rigeur for any high HP motor.

The best upgrade for you would be to build an 2.2S spec motor or stroke the car for a 2.4 using the same pistons. Usually, by the time that the cost for this is added up, most people just swap motors. This of course, has its own hidden costs.