1971 2.2T power increase
03-08-2002, 10:48 AM
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1971 2.2T power increase
I have a '71 2.2T and want to get more power from this - early days but am interested if anyone knows what is involved in upgrading the engine to an 'S' spec. or similar. Does this purely involve top-end work or is it more complex than that.
Any thoughts / comments appreciated
cheers
andy
Any thoughts / comments appreciated
cheers
andy
03-08-2002, 08:32 PM
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I went thru the same exercise you are going thru. My car started life as a 1969 911T, after a chain tensioner collapse, I decided to make it into a "S" engine.
Basically its a top end re-do (assuming you a wont be racing the car)
If you decide to race the car, you should get an "S" crank it is forged and counterweighted, the "T" crank is cast and isnt counterwieghted.
The "T" crank is fine for street use with the increased performance you will see by making the top end to "S" specs.
You may have to have the ports in the heads opened up a bit to
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Basically its a top end re-do (assuming you a wont be racing the car)
If you decide to race the car, you should get an "S" crank it is forged and counterweighted, the "T" crank is cast and isnt counterwieghted.
The "T" crank is fine for street use with the increased performance you will see by making the top end to "S" specs.
You may have to have the ports in the heads opened up a bit to
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
03-09-2002, 10:14 AM
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If you do the cams, heads, pistons and distributor to 2.2S spec, and you're using carbs, your HP should go from 125 HP @ 5800 RPM up to ~170 @ 6500 RPM. Your torque will also go up from 130 lb/ft @ 4200 up to almost 147 lb/ft all the way up at 5200 RPM. So the motor will get a lot peakier. If you want the full S's 180 HP @6500, you'll also need to get an S MFI system which could get pricy. Either way, the S really doesn't do a lot as you can tell from the torque numbers until you really get the motor wound up. Picture always driving around town at 4000 RPM plus.
A couple of other options to consider:
1) Go for an E+ spec and keep your current T/E heads and use E cams and S pistons. You might need to do the distributor curve also. An E will easily rev up to 7000 (I've got a 2.0 E+), but is happy tooling around town at 2000 RPM.
2) Go for a "Rally" spec. set-up and use S pistons and cams with the T/E heads. Porsche had a rally engine like this in 67/68 which made about 150 HP from 2 liters using 46 Webers versus the carb'd S from that period that made 160 HP on 40 Webers. I guess you could extrapolate that this engine might make about 160 HP in a 2.2 but I have no idea how the torque is. Given that it was a Rally engine, I doubt that it would be that bad.
No matter what you do, you might find that you can't get your Zeniths to adjust at which point you'll need to get some Webers.
Let us know what you do and how it turns out.
A couple of other options to consider:
1) Go for an E+ spec and keep your current T/E heads and use E cams and S pistons. You might need to do the distributor curve also. An E will easily rev up to 7000 (I've got a 2.0 E+), but is happy tooling around town at 2000 RPM.
2) Go for a "Rally" spec. set-up and use S pistons and cams with the T/E heads. Porsche had a rally engine like this in 67/68 which made about 150 HP from 2 liters using 46 Webers versus the carb'd S from that period that made 160 HP on 40 Webers. I guess you could extrapolate that this engine might make about 160 HP in a 2.2 but I have no idea how the torque is. Given that it was a Rally engine, I doubt that it would be that bad.
No matter what you do, you might find that you can't get your Zeniths to adjust at which point you'll need to get some Webers.
Let us know what you do and how it turns out.
