Early 911 Project -- Technical Questions

[csawyer]

I have been thinking about how to come up with the perfect early 911 driver which has no inherent value, so that you can just drive it, and don't have to worry about insurance and so forth.

I was thinking about buying a 2.2 liter 911T, and making a few tweaks to make it go, stop, and steer more like an S.

I realize that the aluminum S brakes will be hard to find and prohibitively expensive, but what about brakes from the 3.3 Turbo? Do they fit? Would they work without a servo? (I had a 78 911SC which had had the servo disabled by the PO, and it worked fine, but the turbo brakes are quite a bit larger). I am guessing at a minimum the hubs would have to be changed. I don't really like the brakes from later non-turbo cars as they are single-piston jobs which have a different feel. I think the Turbo brakes are much more in the spirit of the four-piston aluminum S calipers.

Steering shouldn't be too hard -- I think the torsion bars are the same; just the shocks and sway bars are different (IIRC). I always preferred, however, the semi-trailing arms from the later cars, which are sand-cast aluminum instead of rust-prone black painted steel. Does anyone know if they fit?

The big thing, I know, will be the engine, but I think I would really enjoy building one of these myself. I have a fantastic workshop at home which I've never really used since I built the house 14 years ago. If I'm not mistaken, the "T" motor has a different and inferior crankshaft, without full counterweighting, and simple cast iron, instead of the lovely forged and fully counterweighted crankshaft of the "S". I guess the "S" cranks are available somewhere, aren't they? And maybe I could use the RS jugs -- making 2.5 liters displacement, if I'm not mistaken. With the "S" cam, cylinder heads, and so forth. What do you guys think -- could I accumulate the parts to build such an engine for a reasonable amount of cash, say $20 -- $25k?

This is still a bit of a pipe dream so far, but if anyone feels like sharing some information or advice, I will be grateful!

[csawyer]

I just saw theses:

http://www.early911sregistry.org/for...er-Recreations

Wow!!! I guess the brake question disappears.

[Jim Breazeale]

I have been thinking about how to come up with the perfect early 911 driver which has no inherent value, so that you can just drive it, and don't have to worry about insurance and so forth.

I was thinking about buying a 2.2 liter 911T, and making a few tweaks to make it go, stop, and steer more like an S.

I realize that the aluminum S brakes will be hard to find and prohibitively expensive, but what about brakes from the 3.3 Turbo? Do they fit? Would they work without a servo? (I had a 78 911SC which had had the servo disabled by the PO, and it worked fine, but the turbo brakes are quite a bit larger). I am guessing at a minimum the hubs would have to be changed. I don't really like the brakes from later non-turbo cars as they are single-piston jobs which have a different feel. I think the Turbo brakes are much more in the spirit of the four-piston aluminum S calipers.

Steering shouldn't be too hard -- I think the torsion bars are the same; just the shocks and sway bars are different (IIRC). I always preferred, however, the semi-trailing arms from the later cars, which are sand-cast aluminum instead of rust-prone black painted steel. Does anyone know if they fit?

The big thing, I know, will be the engine, but I think I would really enjoy building one of these myself. I have a fantastic workshop at home which I've never really used since I built the house 14 years ago. If I'm not mistaken, the "T" motor has a different and inferior crankshaft, without full counterweighting, and simple cast iron, instead of the lovely forged and fully counterweighted crankshaft of the "S". I guess the "S" cranks are available somewhere, aren't they? And maybe I could use the RS jugs -- making 2.5 liters displacement, if I'm not mistaken. With the "S" cam, cylinder heads, and so forth. What do you guys think -- could I accumulate the parts to build such an engine for a reasonable amount of cash, say $20 -- $25k?

This is still a bit of a pipe dream so far, but if anyone feels like sharing some information or advice, I will be grateful!

I hate to bust your bubble, but you have a few misconceptions about Aluminum S brakes. Your "wonderful" S brake calipers only have one piston, not two, and it is the same size as the piston in a T caliper. S brakes ain't worth the money, IMHO. If you want a early S to stop, you need to remove the cool looking Aluminum calipers and sell them to someone that has the same misconceptions as you. Then buy a pair of ugly 911SC steel calipers for a fraction of the price of Aluminum S calipers and install those (they bolt right on) .
Yes, aluminum rear trailing arms will fit right on a 72 or 73 chassis. They will work on 69 through 71 chassis, also but there are a couple of issues that come up.

Regards

Jim
40 year owner of a 71 911T with no inherent value, especially since it is Sepia Brown.
It has those old steel rear trailing arms and cast iron SC brake calipers, too
It will blow the doors off any "numbers matching "S" or RS, though.

[csawyer]

I hate to bust your bubble, but you have a few misconceptions about Aluminum S brakes. Your "wonderful" S brake calipers only have one piston, not two, and it is the same size as the piston in a T caliper. S brakes ain't worth the money, IMHO. If you want a early S to stop, you need to remove the cool looking Aluminum calipers and sell them to someone that has the same misconceptions as you. Then buy a pair of ugly 911SC steel calipers for a fraction of the price of Aluminum S calipers and install those (they bolt right on) .
Yes, aluminum rear trailing arms will fit right on a 72 or 73 chassis. They will work on 69 through 71 chassis, also but there are a couple of issues that come up.

Regards

Jim
40 year owner of a 71 911T with no inherent value, especially since it is Sepia Brown.
It has those old steel rear trailing arms and cast iron SC brake calipers, too
It will blow the doors off any "numbers matching "S" or RS, though.

One piston???

It's been a long time, but can my memory be so defective?

And I certainly didn't mean to denigrate your "T" :flowers: -- why, I'm looking for one myself! By "no inherent value" I didn't mean T's in general, I just mean some neglected probably bastardized example which can be turned into a nice driver.

[Silverbullit]

Pretty sure he meant one-piston-per-pad.

[Jim Breazeale]

No Worries!


Regards

Jim

[Eminence Gris]

I have been thinking about how to come up with the perfect early 911 driver which has no inherent value, so that you can just drive it, and don't have to worry about insurance and so forth.

I was thinking about buying a 2.2 liter 911T, and making a few tweaks to make it go, stop, and steer more like an S.

I realize that the aluminum S brakes will be hard to find and prohibitively expensive, but what about brakes from the 3.3 Turbo? Do they fit? Would they work without a servo? (I had a 78 911SC which had had the servo disabled by the PO, and it worked fine, but the turbo brakes are quite a bit larger). I am guessing at a minimum the hubs would have to be changed. I don't really like the brakes from later non-turbo cars as they are single-piston jobs which have a different feel. I think the Turbo brakes are much more in the spirit of the four-piston aluminum S calipers.

Steering shouldn't be too hard -- I think the torsion bars are the same; just the shocks and sway bars are different (IIRC). I always preferred, however, the semi-trailing arms from the later cars, which are sand-cast aluminum instead of rust-prone black painted steel. Does anyone know if they fit?

The big thing, I know, will be the engine, but I think I would really enjoy building one of these myself. I have a fantastic workshop at home which I've never really used since I built the house 14 years ago. If I'm not mistaken, the "T" motor has a different and inferior crankshaft, without full counterweighting, and simple cast iron, instead of the lovely forged and fully counterweighted crankshaft of the "S". I guess the "S" cranks are available somewhere, aren't they? And maybe I could use the RS jugs -- making 2.5 liters displacement, if I'm not mistaken. With the "S" cam, cylinder heads, and so forth. What do you guys think -- could I accumulate the parts to build such an engine for a reasonable amount of cash, say $20 -- $25k?

This is still a bit of a pipe dream so far, but if anyone feels like sharing some information or advice, I will be grateful!

The 911 is not 'under braked.' T brakes are absolutely fine. You can get the additional pad area of the S aluminum calipers with SC calipers, as Jim says.. Either of those choices require struts with 3.5" ears. There are adapters made to put larger brakes on the chassis, but even with the 2.5 you envision, you're fine with the T setup.

Back in the day, we were in love with the aluminum arms, but not so much any more. The steel ones are just fine.

I know of a 2.2 T sunroof coupe that will be coming on the market and probably suit your needs, but at $40K or so, you'll probably be looking for a bit more of a project. Maybe one without a matching engine. Cheapest route is usually the 'abandoned project' which is apart and made ugly by the early stages of the process... If you have vision, you can get an okay deal that way. The day of the 'good deal early 911 driver' is long past, I'm afraid.

[Jim Breazeale]

Pretty sure he meant one-piston-per-pad.

Thanks Brian. Yes, that is what I meant.
Too bad, your car only has one piston per pad, as well.

Regards

Jim

[csawyer]

The 911 is not 'under braked.' T brakes are absolutely fine. You can get the additional pad area of the S aluminum calipers with SC calipers, as Jim says.. Either of those choices require struts with 3.5" ears. There are adapters made to put larger brakes on the chassis, but even with the 2.5 you envision, you're fine with the T setup.

Back in the day, we were in love with the aluminum arms, but not so much any more. The steel ones are just fine.

I know of a 2.2 T sunroof coupe that will be coming on the market and probably suit your needs, but at $40K or so, you'll probably be looking for a bit more of a project. Maybe one without a matching engine. Cheapest route is usually the 'abandoned project' which is apart and made ugly by the early stages of the process... If you have vision, you can get an okay deal that way. The day of the 'good deal early 911 driver' is long past, I'm afraid.

Thanks, very useful information!

I had several SC's and remember I didn't like the way the brakes felt compared to the early cars. But googling it, it looks like the SC is a two-pot caliper too, though, contrary to what I remember -- man, my memory is getting really bad -- must be incipient Alzheimers . . . Maybe it was just because I didn't like the servo.

So why do you say you're disenchanted with the aluminum semi-trailing arms? Aren't they much stiffer and better?


Yes, an abandoned project was really just what I had in mind, maybe even one without a motor.

[91133]

So why do you say you're disenchanted with the aluminum semi-trailing arms? Aren't they much stiffer and better?

I'm in the middle of the style of outcome you're talking about at least in a driving sense except I pretty much threw the budget out the window.

However, I can add a few cents to the discussion.

I've gone with the Alu S callipers as I wanted period correct-ish and my own experiences with S callipers have been pretty god in road and track usage. One issue with the old callipers these day sis that a lot of them are splayed so any benefit you get is right out the door. They are also quite expensive 'for what you get'. An option you might want to look at for all four corners is Boxster brakes - TRE makes a kit. Don't forget to consider what may need to be done on the master cylinder front to get the real benefit.

As for trailing arms…yes, doing them too. They are sort of an easy swap on the 72 and 73 cars but there are still traps for young players. You'll need the late hubs and you also need to replace the eccentric camber adjuster bolt - the new part is 901 333 133 06

Switching to the Alu arms saves 5.5lbs per arm so the change is probably more mental than real and the money could be spent elsewhere to greater effect - that old T will probably come with bogs struts for instance and probably no sway bars at all…. And yes, I have swapped in Alu arms and done all the sway bar mods etc etc...

Cheers,
Mark