internals on 2.0? early turbo?

[mnmike]

does the 69 2.0 have forged internals? Do any of the naturally aspirated pre-78 motors have forged internals? Whats the c/r on them?

Also has anyone turbocharged these early motors before? Would it require different internals or carbs? Im thinking along the lines of a very small turbo at say 5 psi..

[beepbeep]

Hello!

What do you mean by "forged internals"?

Turbocharging will increase the cylinder pressure and put some extra strain on piston but frankly, majority of loads on rods/wrist comes from revving, not from turbocharging. Piston that is returning from TDC puts more strain on rods/crank than turbocharged combustion taking place in cylinder. As long as piston dishes are up to task, you are OK.

With other words yes, you coul probably turbocharge it as long as your C/R, tranmission and driveline can withstand the torque.

My guess is that your tranny and clutch will fail before engine internals do.

[mnmike]

how much power can the 69 4 speed take?

[beepbeep]

I have no idea. Not much, I suppose.

Correction: it's actually not a question of how much power but how much torque it can take. It's the torque that kills the transmission, power just makes it heat up more.

[mnmike]

so say 175 hp and the same torque would be too much?

[beepbeep]

As I said, power doesn't mean a squat (as long as you have adequate cooling). You could brake it with 2hp and live happily with 400hp). It's torque that kills it. What's original torque figure for 2.0? I wouldn't go past 1.4 of that.

But whole project it a bit cheezy though. I wouldn't do it. Let the little old car live as it is. It's not made to be turbocharged. You will spend more money turbocharging it with acceptable results than it would cost you to sell it and buy a project car that can be turbocharged more easily.

You would need EFI, better brakes, another fuel system and whatnot. It's just not worth it.

[jluetjen]

Originally posted by mnmike
so say 175 hp and the same torque would be too much?

First off, if you supercharge a motor and the torque stays the same -- you've done something wrong. In general the torque will increase because you're pushing more air into the motor over roughly the same rev range.

Secondly, if you're target is 175 HP, why bother going through the trouble. Just plop an SC motor in there and you're done. The throttle response will be better then a turbo'd motor, and chances are the weight and expense will be less

[mnmike]

apparently putting an sc motor in is extremely unrealistic in the early cars from what ive read here.

I meant the same torque as in 175 hp and 175 tq, not 175 hp and stock tq, that wouldnt make sense (especially with a turbo because generally tq is equal or greater than the hp). It wouldnt have to be converted to efi. People have used f/i on carburated cars since the dawn of time. I think one of the first turbo passenger vehicles was the corvair back in the 60s. Ironically, thats also a flat, air cooled 6 iirc as well (a friend of mine who collects cars has one thats rated at 180hp).

Just trying to find a unique way of making a bit of extra power. I think a swb car with a small turbo engine would be very cool personally. I could piece the turbo setup together for very cheap, the tuning is what would be complex. Just trying to figure out how the motor would take boost. Is the compression ratio pretty low?

[beepbeep]

Well you could use programmable boost controller to cap the torque and just fill-in boost progressivly as torque starts to fall off...thus keeping torque curve flat from say, 2000 to 6000 RPM. This is very common on new turbocharged cars.


That would save the gearbox and give really progressive and driveable engine. Engine being a 2.0, you could use any of small turbochargers available.

T25 from SAAB, GT17 from SAAB 9-5, KKK's from VW 1.8T's etc etc.

[jluetjen]

Originally posted by mnmike
apparently putting an sc motor in is extremely unrealistic in the early cars from what ive read here.

No it's not. Especially if you convert it from CIS to carbs. You'll need to change the clutch to fit the existing 901 style transaxle, but I don't think that this is rocket-science. In most cases, a 911 long-block is a 911 long-block, and are pretty much interchangable excepting such details as distributors and exhaust flanges. If a 3.0 is too much of a leap, putting in a 2.7 is even less of a big deal.

[mnmike]

Originally posted by beepbeep
Well you could use programmable boost controller to cap the torque and just fill-in boost progressivly as torque starts to fall off...thus keeping torque curve flat from say, 2000 to 6000 RPM. This is very common on new turbocharged cars.


That would save the gearbox and give really progressive and driveable engine. Engine being a 2.0, you could use any of small turbochargers available.

T25 from SAAB, GT17 from SAAB 9-5, KKK's from VW 1.8T's etc etc.

exactly, i was thinking the vw turbo from the 1.8t's. You can find them dirt cheap (bc people upgrade) and they're small.

[mnmike]

Originally posted by jluetjen
No it's not. Especially if you convert it from CIS to carbs. You'll need to change the clutch to fit the existing 901 style transaxle, but I don't think that this is rocket-science. In most cases, a 911 long-block is a 911 long-block, and are pretty much interchangable excepting such details as distributors and exhaust flanges. If a 3.0 is too much of a leap, putting in a 2.7 is even less of a big deal.

even on a swb? I thought you had to convert all the suspension and rear

[911pcars]

To answer your question directly - I think you realize (by now) that substantial additions of torque and power will upset the balance of the vehicle. You will have to compensate and upgrade other areas as well.

The '69 base T engine uses a cast crankcase and pistons. Con rods are forged, as are all 911s.

The '69 S crankshaft (not sure about E) is forged as are the pistons. However, you'll want low compression with a boosted engine. S pistons do not provide low compression.

You'll also need to select the correct turbocharger for the application. A guess in this area negates much cost in materials and fabrication and might shorten engine life or make it undriveable if you get it running. Do your homework first before pulling out the credit card. Corky Bell's turbocharging book is a pretty good primer on the subject.

Hope this helps,
Sherwood

[mnmike]

that is helpful. I just need to now find out what the c/r is, and it would be good to know if the crank or pistons are forged. I can select a turbo by reading compressor maps. Basically it would be a very small turbo.

[dhrcr911s]

Suspension conversion only needs to take place if you start updating the 901 Tranny...

[mnmike]

does anyone know where there is a diagram of compression ratios and/or other 911 engine info such as bore/stroke etc?

[911pcars]

Have you tried looking here yet? I literally mean ......here:

http://www.pelicanparts.com/911/technical_specs/911_chassis_info.htm

This is one of many sources for Porsche engine specs. Wayne (owner) has a few books on the subject (here too) as does B. Anderson "911 Performance Handbook" and countless other books by numerous authors. The web is full of info too if you're on a budget.

IOW, do a search and you'll find.

Hope this helps,
Sherwood

[mnmike]

Originally posted by 911pcars
Have you tried looking here yet? I literally mean ......here:

http://www.pelicanparts.com/911/technical_specs/911_chassis_info.htm

This is one of many sources for Porsche engine specs. Wayne (owner) has a few books on the subject (here too) as does B. Anderson "911 Performance Handbook" and countless other books by numerous authors. The web is full of info too if you're on a budget.

IOW, do a search and you'll find.

Hope this helps,
Sherwood

thats what i was looking for, i couldnt find it for some reason..

[mnmike]

so do the air-cooled 911 turbo's only have oil cooling for the turbochargers. Most turbo's seem to have both oil and water cooling.

[911pcars]

Water-cooled turbos don't get as hot as oil-cooled versions. Alas, there is no water in the air-cooled 911 - not until someone successfully puts together a water-cooled turbocharger system for the coolant-less engine.

Sherwood