My choice of used engines/ parts

[sww914]

I'm trading some labor with a friend and I'll pretty much have my choice of his parts and engines. I will be installing it in a 914 dedicated track car. What class I end up in doesn't really matter because I probably won't make enough events to make a run at the points anyway. I've been running a hotrod 4 cyl for several years. He has several engines in various states of disrepair;

Complete 2.7, assembled, recently "rebuilt" by a non-Porsche mechanic. removed from the car after a few hundred miles when it dumped oil all over the PO's driveway.

Complete 2.7 in boxes, case already time-serted, but it probably needs some machine work.

Complete 2.2s in boxes, stock, worn out, and needs 1 piston.

Complete 2.0t or 2.2t in boxes, probably not my best choice.
Any of them will come with my choice of 3 good(?) sets of carbs and a used 914-6 exhaust.
None of them will come with any nice high compression pistons or gnarly cams, except for the 2.2s with the stock stuff.
I'm looking for the best bang for the buck, as is everyone else. If the complete, assembled 2.7 will stay together for awhile, I could do the conversion now and rebuild it with nice cams, head studs, pistons, twin plug, etc. later, dividing the work and the expense into 2 chapters. If I chose this route, any ideas of what's available and for how much $$$ in cams and P&C's for a 2.7?
How difficult will it e to find 1 S piston in the right weight group?
Keep in mind that it's a track only car with an M,S,X, or a KA, Q, V gearbox depending on which track I'll be running, so peakiness or drivablity aren't issues I'm concerned with.

[sww914]

One other thing- What does it take to build a 2.5 short stroke?

[Grady Clay]

sww914,

There are the makings of some good engines for your purpose. Be sure and read the rules for the class(s) you intend to run.

I would not assume the assembled 2.7 is suitable for your purpose. I recommend you build exactly what you want and know every little detail is correct.

First, investigate the condition of the 2.7 7R cases. If one doesn’t need repair (other than inserts for cylinder studs and the oil pressure relief mod) you have a find. Next will be the condition of the cranks and rods. At this point I would consider both the 66 mm cranks and the 70.4 mm cranks. A through inspection of all the rods are in order.

Does the 2.2S basket case have the complete MFI? That is a real find and very desirable as are those heads and cams.

For your competition purposes 40IDA may be suitable. If you build a carbureted 2.7, you might consider the 46 mm PMO. The 2.2S MFI can be made to work any size to 3.0+ and will add 10++ hp.

It appears there are several (2?) sets of 90 mm cylinders. If Nikasil, use as is, if Alusil, have them Nikasil plated. Then have Steve at Rennsport fit some very high compression race pistons. These are relatively short lived compared to Mahle race pistons but 1/4 cost.

One new part I recommend is the current GT3 Cup oil pump. It is less expensive than the Turbo pump and higher capacity.

I recommend you discuss with Pelican Camgrinder about the 911S cam profile, reconditioning rockers and shafts and adding center oiling (like RSR, 935 and 911SCRS).

Since you will need an oil sump tank, I recommend you use the 964 oil filter in place of the engine oil cooler and an oil tank similar to the GT3 tank (close to the engine). The ’74-> thermostat to a front cooler will work fine.

Yes, get the OE 914-6 exhaust. You may find you want a set of larger headers but you should have that exhaust in hand.

If you can, pick and choose among all the engine parts. You may find the best set.

If you keep this engine with “S” cams or close, 7300 rpm limit and well engineered & built, it will last many seasons with only rings and valves.

Yes, twin plug will help greatly.

As with any high compression race engine, using high octane race fuel is critical.


I recommend you help the seller put the remaining engine parts in complete sets with good documentation. That should include documentation of the existence and condition of every engine part, including hardware, etc. This will allow him to use or sell with good knowledge. This is something that you can provide with your gaining expertise (with Forum help).

Your Type 914 transmission can be easily converted to a 225 mm pull-type clutch by relocating the clutch arm pivot, using the Type 911 2.2 clutch arm, having made a non-pulley clutch cable and a lightened cast steel 2.2-2.7 flywheel. I recommend a transmission oil pump, cooler and filter.

Do you have 5-bolt hubs? I recommend that and using the 108 mm CV joints. For a track only car, I like a solid spool over a LSD. A welded open differential is inexpensive and effective.


If you search on my name and 914-6, you will find a lot. I have an original six (first raced CP in ’71) that I raced in CP and GT2. The current three engines are 91x66 being converted to 70.4x92. All are full of Porsche race parts.


You have a unique opportunity to trade for the pieces for a very suitable powerful and lightweight engine. It is still going to take significant expense. Be prepared.



As an aside, air cooled 911 race engines are the best in the world. They are reasonably powerful (not the ultimate), when built correctly they are very reliable and very drivable in competition.

Particularly with your four, I recommend you consider the “Rubbermaid Solution”. With a high compression 911 also very important.

Best,
Grady

[sww914]

No MFI, that would be my first choice, but he doesn't have any. So is a 2.5ss the 66mm crank with the 90mm cylinders? Would anyone choose that over a 2.7? I would think that the short stroke with bigger cylinders would be a higher RPM type motor, so do I need better rods with that combo, or just use stock rods and keep the RPM's down.
I already have an oil tank, a DWD design tank. Don of DWD is a close friend, and he was kind enough to give me blemished tank and filler neck. I also already have a F oil cooler with 1/2" hoses, will these be large enough or should I upgrade those?
My car is already 5 lugs with my old front calipers in the rear and new BMW calipers- 3" spacing in the front.
What is the Rubbermaid solution?