Any thoughts on a course of action for HP upgrades for the stock 1970 2.2 T motor?

[ARCSinAK]

This motor has Zenth 40's and complete split case, new P/C, stock rebuild 9K before I purchased the T. Can you see noticeable increase with just JE 10.5 pistons and E cams? Looking to not spend 6K.

Your knowledge is appreciated.

Regards-

JS

[trak ratt]

Generally speaking a full point bump in compression = ~10% increase in HP. Not sure if it's linier if you add more CR.

So;
1970-1971 911 T
2195 cc
125 bhp @ 5800 rpm
177 NM @ 4200 rpm
compression: 8.6:1

1970-1971 911 E
2195 cc
155 bhp @ 6200 rpm
191 NM @ 4500 rpm
compression: 9.1:1

2.2 E also had bigger valves and intake/exhaust ports and MFI.

Early exhausts were quite good so unless you went to go to a real good set of headers not much to be gained there

10.5 CR might be pushing it for todays pump gas and stock ignition. Also, Ts had iron cylinders so you will lose some efficiency there.

So all things considered I'd figure about 145-150 HP if you are attentive to tuning. Your Zeniths should be adequate for this setup but will reguire a lot of tuning to optimize your setup.

I had a '71 2.2 for many years and have often thought about upgrading but the cost seems just to much for any real gain on an otherwise stock T.

That said I do have a short stroke 2.5 in the shed w/E cams, ~9.5 CR and Webers I'd like to try in our '71 if I ever get motivated enough. But I got it in a car deal and didn't have to front the $$$ for the update.

[burtm5]

I had a stock 71 T. Was worn out in 1980 so I put 2.7 8.5 nickies for 2.515 ltr 40 webers, ssi, L/E cams and stock 32 mm intake/exhaust head. on a track it would pull with a stock 3.2. with weight differences I assumed about 175 crank hp. ran well and dependably. Never have figured out the exact cr with the 66 crank and the 90 pistons. If I had it over again I would like to have had cw crank and more compresion better heads but back in the early 80s you could get 8.5 RS at most. this lasted for 30 years until it was money shifted at mid ohio. btw the valves in these years are all the same intake and exhaust ports, cr, cams and higher redline because of counter weight cranks and breathing make the difference. best Henry

[Henry Schmidt]

The best upgrade I've found for 71 T is the 2.45 conversion. Cost effective and huge wow appeal when you push the loud pedal.

2.4/2.7 crank and rods
86 mm slip in 9.5:1 compression
Mod "S" cams
36 mm ports.
40 mm Webers

Great mid range power with a peak of 180rwhp @ 6800 rpm.

[jsoderbe]

Hi, sounds interesting, thanks for sharing. I am trying to figure out which configuration that gives most bang for he buck, so to speak. I have some engines laying around, and parts, so I would prefer to use stock parts where possible.

Henry, or anyone else who know; a few questions:

- "mod" S cams, does that mean another profile than S?
- The weber setup, which internals would that be?
- Slip-in, which cylinders would that be? Could I just bore the 84 mm I have?
- The 36 mm ports, would that mean just open up the original heads?
- Do I need to do any more machining to case or parts?

Any input would be very appreciated!


Regards,

Johan

[jsoderbe]

Bumperoo for any ideas.... :-)

Johan

[RD911T]

Has anyone documented a 2.45 conversion such as Henry mentioned above? I'd be interested in reading about it.

Tom

[tadd]

Mod S is a 'modification' of the factory S profile. Typically a bit more lift is added. There is also the mod solex and mod 906 ...oh wait, the factory did that one...RSR sprint .

Short of tossing in a 3.0, and I do hate that thought, but it is cost effective, do a search on Grady and 2.8S. The 2.8 cylinders are a bit harder to find but are around. Figure $1.2k for replate and hone to fit. 90 mm 2.7 cylinders are more common and wouldn't be far off the mark. Don't bore stock 90s to 92 mm. They get real thin at the CE groove and chip if a detonation even looks crosseyed.

There is nothing wrong with the T crank. It will spin up quick, just keep it to 7.2k rpm.

You will need to chase up some heads. The T heads won't move enough air. The stock 36 mm heads flow really well. The factory did a good job. They will feed a 7.2k limit 2.8/2.9 (70.4 mm crank) or a 8.5k rpm 2.5/2.6 (66 mm), just.

IMHO the best $$$ you can spend is the $400 to get your heads twin plugged. Can't afford the fancy, but awesome looking twin plug distributor just yet? Just put the lower plugs in and put the covers right back on and drive till you can. It will future proof you to gasoline and will make the engine even at stock CRs. Less advance is good for longevity. If your going to EFI, the microsquirt is pre built with surface mount components, has twin plug built in, is darn tiny, weather sealed, and has both sets of trims. Oh yea, it's like $340.

You will spend, it just depends on where .

t

[jsoderbe]

Tadd, you actually wrote $340 for a Megasquirt? Both fuel and ignition? I had no idea they were that cheap.

I hope I am not hijacking this thread, since I have the same question as the o.p.; my goal is to spend as little as possible, getting as much as possible. I have tons of engines and parts, and I would like to combine them. I wont spend $1200 on cylinders, that is for sure. Most likely I will even stay on single plug, to keep costs down.

Basically, if I get positive answers on my questions above, I do only need to buy JE pistons, everything else is already on the shelf....

Regards,

Johan

[cmcfaul]

JE 2.4 L, 9.5 CR pistons (or 10.0 cr if you want to push the envelope with single plug) and the Mod solex cam is a perfect combination. The mod solex will reduce the CR a bit but allow the engine to breath all the way to 7300 RPM's +. thinking 200 hp easy with lots of torque.

Chris
73 911 E (with above mod)

[RD911T]

Here's what Henry said in another thread about his 2.45:

"I had a 69 911 T with matching numbers and wanted the most drivable engine but still wanted to retain the original engine.
I elected to build a 2.45 (70.4X 86). This is done by changing from the short stroke 66mm (2.0-2.2) non counter weighted crank to a 70.4 (2.4/2.7) counter weighted crank. Of course the rods are changed to match the crank.
The 86mm Ps & Cs are a biral cylinder (AA Performance) with a JE forged piston.
I chose a 9.5:1 compression ratio and a DC 40 (Mod "S") cam.
We ported the heads to 36mm and used Weber 40 mm carbs.
We added twin plug for the wow appeal but at 9.5:1 twin plugging is not necessary.
The engine produced good low end and 180 RWHP @6500 with more on tap as the engine breaks in.
The best thing about this configuration is that the cylinders slip in and the over all project is more or less a straight forward rebuild."

Here's the link to the other thread:

911 T 1969, need more power.

Tom