Hotrod base - 1970 or 1973 911T?

[Tremelune]

I've owned several 80s cars, but never a longhood. I have the opportunity to purchase one of two cars I like, and I'm hoping that the next air-cooled 911 I buy will be my last. Originality means little to me, but I don't want to hotrod myself into a car that's in constant need of attention and terrible to put around town in. I don't want to get into too much detail on the cars, as there are other important factors in play with regard to which one to buy, but I'll need to make a Decision soon, and I'd like to have as much info as I can beforehand.

My questions are about the engine and transmission, as it relates to "builds". Both motors will need to be opened up, and I'm trying to understand what is possible with a 2.2 vs a 2.4 in terms of power, hassle, and cost. More displacement = more power, but is there anything more than that between the 2.2 and 2.4? Should I fear a 50-year-old magnesium case?

I'm also wondering if it would make more sense to swap in a 3.0/3.2 rather than try and squeeze power out of the older engines. Are they much heavier? More sluggish...? Everyone likes torque and power, but quick revs can make for fun shifting. I'm not drag-racing anyone, but a it's more fun to do 0-60 in 6s than 8s.

I'm likely to mothball the carbs in favor of distributorless EFI (X-Factory, Rasant et al) in the interest of reliability, smoothness, maintenance, and due to the fact that I'm blessed with the possibility of driving from a hot ocean to a snowy mountain on the same day. The car would be street-driven, but would spend a lot of time bouncing off redline in mountains/canyons. Anything can be done with enough money, but I'm trying to understand the bang-for-buck route, and what I gain or lose by going cheap or stretching a bit. Is condition still king, or does one motor have significantly more potential than the other (in terms of power, lightness, flaws, etc)?

How about the 901 vs the 915? How does the shifting feel between the two if they're both sorted? "Feel" longevity? Does the 901 have as many, ah, corrective upgrades as the 915 does (and does it need them)? I had a 915 and it was good once you got out of 1st gear, but it had various Wevo upgrades, and had been freshly rebuilt. 1st gear wasn't much fun around town (but I guess "around town" isn't all that much fun to begin with).

Is the 901 really at its torque limits, or is it more about how the car is driven? If a 3.2 wound up in this car, could the 901 be retained? I'm not out here dumping clutches, just running through gears at WOT from time to time. Should I fear 50-year-old magnesium cases...?

I appreciate any entertaining of my nebulous musings...

[Chris Pomares]

My two cents. A 901 transmission is not a 0 to 60 box. If hammered from a dead stop, a high torque engine will stress 1st gear and worse case strip it off the shaft as it's cantilevered (not supported on both sides). I run a 901 and don't pound 1st gear. Second through fifth are much stronger. As far as shifting feel I much prefer the 901 over the 915. That being said if you are a 0 to 60 guy and want a hot 3.0 or 3.2 I would suggest the 915 as it can handle more power.
As far a engines go you are talking 6 cylinder engines and I'll let the folks with 6's in their cars chime in. As far as 70-71's with 2.2's and 72-73's with 2.4's once again I'll let the other guys chime in. For me I'd go with a 72 or 73 as it gives the owner the ability to go with 74 and later aluminum trailing arms without too much fuss. I like to fiddle with suspensions on both the SWB and LWB cars. Here we are talking LWB and the 72 and 73 allow the most rear suspension alterations with the least fuss.
I am currently finishing a 69E Targa with a 2.4 Mod S engine built buy a business that has a very good name. Don't bother to ask as I won't give their name as this engine is probably the exception from them. The mag case is leaking and seeping. It looks like it was attacked by termites. If it was me I'd look for an aluminum case engine.
Good luck on your hunt. I'm a huge long hood fan. Be careful and have someone who really knows these cars inspect the cars you might purchase. Because of their age a lot of the cars are lipstick on a pig. The paint, interior, and engine compartment look nice but there is RUST lurking. You could eat 911SC and Carrera money in a heartbeat just having the rust repaired PROPERLY. What is properly. It is the way you hope the previous owner had the car repaired or restored before you bought it. Go talk to the best restoration shops and see how they do it. Your 80's cars had rust protection. These had none.
So after all I've said I believe what should be the top priority is find the most rust free car you can and have fun building your hot rod.
Probably the best place to start your hunt is right here on this registry. Many of the nicest Long Hoods in the world belong to this group. And if your really lucky someone is ready to sell a car that's specked just the way you want it.

[Longballa]

I'd go with the 73 and put RS flares on it and a 3.2SS EFI engine with short gears. Aluminum trailing arms etc................. It's only money right? 930 calipers, Ok I'll stop now.

[geneulm]

Which one to go for is easy: buy the one that is in the best possible body condition. These are old cars and all have their history; get the one that has been babied, best taken care of and least neglected.

Transmissions: both are fine under street conditions. And with a little help, people have ran 901s with big HP/lot more torque under racing conditions with zero problems. There are plenty of stock versions running 3.0+.

Bang for buck: with the short stroke, take it out to 2.5. With the long stroke, take it out to 2.7/8. Done right these mag cases are fine for hot rod street use — there are boatloads of long lasting examples. The short stroke will do better than the long stroke. The harmonics of the short stroke are just easier on the cases. There will be modest differences in character between the two: short stroke will be more revy, long stroke will be more torquey. But differences at the street level are modest. Again well built examples of both last long and are numerous. There are numerous tried and true engine recipes to work from.

EFI has lots going for it, as all things modern do. But MFI and carbs (Weber’s and PMO) both work fine at multiple altitudes, deliver the goods and look the part. Carbs will give more latitude on engine/cam combos, but even then the problems w matching mfi to engine combinations are WAY overstated. These pumps have quite a bit of adjustment room. Stacks can be machined as required.

Again: buy the example that is in the best condition regardless of year.

[myflat6]

^ good advice here. finding a good base to build a hotrod on can be challenging so be prepared to make concessions. depending on what you are building, i would also plan to budget more (much) for the build phase than the initial purchase. building/restoring/hotrodding these cars is not cheap. having recently gone through a build where i did much of the work myself, i can speak to this first hand

[LongRanger]

. . . owned several 80s cars, but never a longhood. I have the opportunity to purchase one of two cars I like, and I'm hoping that the next air-cooled 911 I buy will be my last. Originality means little to me, but I don't want to hotrod myself into a car that's in constant need of attention and terrible to put around town in . . .

. . . appreciate any entertaining of my nebulous musings . . .

Another thread . . .

https://www.early911sregistry.org/fo...l-Street-Racer

. . . + someone to talk to?





.........................

[RickWhite]

I have two ‘71s, produced within a week of each other. Both have 901 pared with a 2.7, one webers, one EFI.

The 901 has no problem getting the snot kicked out of it. Though as others suggest, first gear is a bit more delicate. I am partial to the 901 because I learned to drive on it; but really, for the track the dogleg is a useful configuration. Someone on here refers to the 901 as a bag of antlers. I have met those transmissions and it is because they are set up poorly. The 901 on my targa is stock, and is the most enjoyable, easy transmission to live with (I did blow out the ‘71 only bolt, so it is not all champagne dreams). I am no fan of short-shift kits, etc. - the cadence of the car benefits from the long throw, and second through fourth is sublime (and takes you well into triple digits). The 915 is fine, and I will be putting one in my coupe just because of the first gear issue and the car takes a beating.

On the 2.2 vs 2.4, the quality of the car matters most (straight, no rust), but beyond that, you probably are going to ditch both engines. Th 2.2 isn’t the best platform unless you want to spend mucho cash to take it to a 2.5 and while the 2.4 can be converted to a 2.7 or 2.8 (and if you can get a MFI with it, that is a huge plus, but then you don’t want to run MFI), later cases are cheap so you might as well put the matching numbers 2.4 on the shelf and get a new case and go wild with that and not worry about destroying the value of your car by blowing up the 2.4 case.

Of course don’t get sucked into the hp game either. The 2.2 and earlier cars are a ton of fun because the torque curves are so steep, you have to be mindful of your RPMs at all times and the sound those engines make is glorious. The 2.7 and later engines are “lazy.” Yes, the 2.7 RS has a distinct power band that kicks in around 4500 that feels like a turbo, but it is nothing like the smaller engines. Part of the pleasure of driving these cars hard is the concentration.

It used to be the best idea was to buy a ‘69 912 to hot rod. They are the lightest of the long hoods, and used to be cheap. However, now they are similar in price to a T, but usually much worse quality because for 30 years almost anything wrong with them totaled the car. As others have said, rust free and straight is everything. Find a great shop, and have them help you find the car, predominately through the network of specialist around the country that can perform adequate PPIs. Hi

So without blowing everything up for you, I’d recommend looking for the cheapest straight and rust-free LWB shell, and going from there (or, look at the mid/late 70s cars - they are easy to backdate and not too much more portly). And yes, building the car is way more expensive than buying (which is why buying someone else’s hot rod is always a good idea, unless the building is part of the pleasure).

[Tremelune]

This is all valuable information, thank you!

In the end, the choice was simple—the '73 had rust, bondo, and parts missing here and there...The '70 that I bought appears to be completely free of rust and straight as an arrow! Fingers crossed, anyway—there's only so much you can do on the ground with a flashlight.

It has the (allegedly) original 2.2L engine and a set of Weber carbs. It blew a big puff of smoke on cold startup, but it dissipated quickly. Other than that it sounds pretty healthy to me, if a bit on the loud side due to numerous tailpipes (and with a rather sloppy shifter). I'm in no rush to mess with the engine if I can avoid it, so I'm gonna spend some time getting familiar with the car and see how it feels!

[Longballa]

Finding a rust/accident free body is what it's all about. Everything else just bolts on. Good find.

[Cruisingnkali]

^ good advice here. finding a good base to build a hotrod on can be challenging so be prepared to make concessions. depending on what you are building, i would also plan to budget more (much) for the build phase than the initial purchase. building/restoring/hotrodding these cars is not cheap. having recently gone through a build where i did much of the work myself, i can speak to this first hand

Which one to go for is easy: buy the one that is in the best possible body condition. These are old cars and all have their history; get the one that has been babied, best taken care of and least neglected.

Transmissions: both are fine under street conditions. And with a little help, people have ran 901s with big HP/lot more torque under racing conditions with zero problems. There are plenty of stock versions running 3.0+.

Bang for buck: with the short stroke, take it out to 2.5. With the long stroke, take it out to 2.7/8. Done right these mag cases are fine for hot rod street use — there are boatloads of long lasting examples. The short stroke will do better than the long stroke. The harmonics of the short stroke are just easier on the cases. There will be modest differences in character between the two: short stroke will be more revy, long stroke will be more torquey. But differences at the street level are modest. Again well built examples of both last long and are numerous. There are numerous tried and true engine recipes to work from.

EFI has lots going for it, as all things modern do. But MFI and carbs (Weber’s and PMO) both work fine at multiple altitudes, deliver the goods and look the part. Carbs will give more latitude on engine/cam combos, but even then the problems w matching mfi to engine combinations are WAY overstated. These pumps have quite a bit of adjustment room. Stacks can be machined as required.

Again: buy the example that is in the best condition regardless of year.

Finding a rust/accident free body is what it's all about. Everything else just bolts on. Good find.

I started with a matching numbers (engine and transmission) rust free and solid 1970T for my hot-rod. Installed a Euro 3.0 with 46mm PMOs (3.2 short stroke). Initially ran my original 901 transmission with a WEVO, but recently upgraded to later 915 with lsd. My main reason was that I did not want to damage my matching 901. Best of luck.