2.2T with 40IDTP3C1 webers to be converted

orion · 06-01-2004, 03:15 PM

First of all, let me say that I'm a newbie at this (forums, engine rebuilding and so on...). I can handle myself around tools though and don't scare easily. Hello out there!
Nine months ago, I became the proud owner (don't spoil it for me...) of a '71 911T Targa. So, after the initial battle with floor rust and clutch problems, the car got to a working condition and I put it to the road. Before long I "felt" that the engine should be torn apart, cleaned, measured and rebuilt in a proper way (the car has classic status now and I intend to keep any improvements/alterations to a minimum or at least non-visible level).
I armed myself with Wayne's "How to rebuild and modify 911 engines" and "101 projects for your porsche 911" plus others like "Porsche 911 performance handbook", "Haynes 911 1965 through 1989 Automotive repair manual", "Weber Tech manual" and the Porsche Factory Workshop manuals. Stripping under way, I have removed and taken apart one of the two carburators trying to determine the level of previous care the car was receiving. My guess is that it has not been in the hands of a mechanic for at least 10 years and and something like 15 years to its previous rebuild (the extent of which I don't know). To my amazement, nothing is broken or out of place. So, with limited budget for upgrades I consider the follwing:
Increase the displacement and compression ration by replacing the crank with a counterweigted 2.4-3.0 crack (replace the piston rods as well because of the journal difference) and the replacement of 911T cams with 911E cams in fear of the lack of low end torque if I were to use something like 911S cams.
Does this sound right so far? Would you consider it to be a good mix? and if so... where does one start to set the two 40IDTP3C1 Webers so that they do what they are supposed to do. Not being sure (didn't measure...) they have 27 mm Chokes, 4.50 Aux Venturis, 1.10 Main jets, 0.45 idle jets, 1.45 Air idle jets, F1 Emulsion tubes, 1.85 Air correctors, 0.50 Acc. pump jets and 1.75 Neddle valves (chokes match but the rest came off the Weber tech manual - the only one I found to even list the existence of these carbs). Needless to say, I have no idea where to start with this.
Has anyone dealt with a similar configuration? Are there any guidelines that I may keep to in order to get through this? The reason I'm tiring you with all this is that I live in Greece and parts are really hard to come by. So, what I selectm should be right for the job since I will most prolly be dealing with shops thousands of Km away.

Thanks again,
Andreas

Engine right after removal...

911pcars · 06-01-2004, 05:40 PM

IMO, the setup of the Webers is the least of your concern at this point. For a dislacement increase with the 2.2, you should review Wayne's and Bruce's book and follow the steps to make room for larger displacement (2.7 crank is max.) . BTW, besides a lot of machine work, you're also looking at new pistons/cylinders. It's doable, but prepare your budget.

I'd put the Webers away for now. When you're ready, they'll require about $200-$250 worth of gaskets and parts plus your labor to rebuild them - unless the throttle shafts are worn, then it's another $400-450. Do you feel light-headed yet?

Consider the cost of this exercise may get you close to a pre-owned, low-mileage 3.6 or, if lucky, you might find a recently rebuilt 2.7, 3.0 or 3.2 that fits your build specs. Do the math, then decide which way to go.

Sherwood

Wayne 962 · Wayne 962's Garage

Cool project. Sherwood's right, first things first. If you're going to all this trouble, I would build it to 2.4S specs. Use a common 2.4/2.7 crank and rods, some JE 'S' pistons, and see if you can reuse your 2.4 barrels. Put in some mod-S cams from Elgin, and you'll have a rocket. You probably want to have the case redone too.

OR...

911T motors are like tractor motors - they are pretty much bulletproof, as they don't much out too much HP. You might be able to resurrect this thing from the dead as-is...

-Wayne

orion · 06-02-2004, 02:08 AM

Thanks for the replies guys!
I was thinking of sticking to my 2.2 pistons/barrels. Is that possible?

As for the engine swap, it is out of the question. The FIA would take away my license plates when the eventual check occured and my chassis and engine numbers did not match.

911pcars · 06-02-2004, 08:42 AM

Orion,
I understand your situation with matching numbers. However, what provisions does the govt. allow should the original engine be "destroyed" or "worn beyond rebuilding"? Do you get my drift?

Okay, stick with 2.2 liters, then make sure everything is optimized for long life and much power.

Sherwood

Wayne 962 · Wayne 962's Garage

The T pistons will be incompatible with a hotter cam. It might work with an E cam but it would be close. I doubt that you could make it work with an 'S' cam - I'm not sure there's enough material on the piston to remove (can't recall).

-Wayne

orion · 06-02-2004, 10:02 AM

Sherwood, I do get your drift. Sadly, the govermment doesn't. The whole situation with classic cars is quite weird. We have incomplete insurance (you can drive the car out only when an official FIA recognized club organizes a rally or tour or whatever) and NO insurance company provides any kind of other contract so that you can feel a little safer about your investment. The idea of a car's price going up as time goes by must be really something that keeps out of bed at night.
In any case, destruction of engine means loss of plates. Unless you someone who knows someone...

As for the T pistons and the E cams, I think I will go for it. I have read the procedure to determine clearance and I try it out. By my calculations (increased stroke but shorter rods), the pistons will come closer to the heads by .6 mm. I don't know the angle of the valves so that I can see how much lower would they get with the E cams, but I imagine I soon will.
I'll keep you posted on this.
How about if I put this upgrade attempt in a different way. It will cost me 1250 euros (can't recall the rate for USD right now) to get the E cams, rods and 2.4 crank (all standard sizes and reconditioned) by giving my old stuff back. Do you feel this amount could be better spent?
Thanks again!

BK911 · BK911's Garage

"By my calculations (increased stroke but shorter rods), the pistons will come closer to the heads by .6 mm."

I'd redo the calculation. It should be the same distance.

In my opinion, I think you are on the right track. Leave everything stock except 2.4 crank, rods and E cams. This is only if your parts are reusable. IF you have to replace parts anyway, don't buy T stuff.

I almost have this exact engine except I have 2.4S pistons instead of the 2.2T pistons, and I have MFI. With the 2.2T pistons you will have a slight compression increase but your pistons are heavier. Maybe a wash as far as power is concerned.

orion · 06-02-2004, 11:19 PM

You trouble me. It is a good 2000 euro for the 2.4S cyl/pistons and I'm trying to complete this on a tight budget. But I'm glad I was not too far off with my conversion plan.
Yesterday I took off the tranny and saw that I got one (the only one so far) part that needs replacement. It is the base of the starter motor. The hole (not sure what to call it) through which the second (shorter) bolt ties it to the tranny housing (not the long one that ties both of them to the case) is broken (it is only half there). The previous mechanic used large washers to increase the area of the bolt head so that it could get some grip on the starter motor housing.
It doesn't look like it is taking much punishment but it is not like I have had much luck finding a used one to scrap the housing. Ever seen anything like it? Does it need immediate replacement?