What is the best bang-for-buck engine build?

[Hi_Fi_Guy]

I have a 1971 911T Targa 2.2 with Zenith carbs. A recent engine fire + almost 100,000 miles has me facing a potential engine rebuild in the near future. My 2.2 is numbers matching and will stay with the car whether rebuilt or not. All things being equal what is the best bang-for-buck engine rebuild in the $15k-$20k budget range?

If you were in this position would you rebuild using the stock 2.2 case or go for a different case, crank, etc.? I'd love to hear from those who have actually built these motors and those who have only dreamt about it. What combo would you build for this car? Car is 100% street use for pleasure and road trips.

Tell me all about your best bang-for-buck builds!

[Trackrash]

Bang for buck is a tough call.

Lots of options.

Bang for buck would be higher compression pistons and E cams, upgrade the carbs to match and a sport muffler helps too.

After that check Wayne's book. But basically bigger bore, more compression, bigger ports, newer crank, etc etc.

No reason why you can't keep the original case.

[Henry Schmidt]

I recommend a 2450. It's the engine I built for my last two long hood cars and for many customers over the years. Concours and hot rod alike.
No need to modify the case other that standard machine work. Line bore, case savers, oil by-pass mod and some 8mm perimeter studs.
Much like the 2.5 ST long stroke engine (70.4x86.7)

70.4 crank (2.4/2.7) and rods
86 mm pistons and cylinders.
9.5:1 compression
36 mm intake ports
Mod "S" cams (performance valve springs)
40mm Webers or PMO
Stock heaters boxes (Dansk or SSI)
Sport muffler
180 RWHP @ 6450 rpm
Great driveabilty and top end performance
If your Zeniths are not burned up they can be rebuilt. (We do that with performance enhancements, in house)

[911pcars]

Best bang for the buck would be to buy a recently rebuilt, pre-owned engine in good condition. They're all expensive to rebuild, but the preliminary $$s already spent are now history. Perhaps the former engine from someone's upgrade program.

Sherwood

[Carbster09]

I like Henry's recipe, but I need a little more "heat". I was considering a 2.8SS w a 7R case I have but I just drove the Targa Cali for three days and I don't rev the motor that hard. Now thinking 2.9 LS w MFI .... or just throw caution to the wind and go Aluminium? I reckon I "need" .... 250++hp

[Walt Fricke]

Why not a used SC engine, maybe with carbs or EFI. And keep your original for the added value you think there will be with it come the time you want to sell the car?

[Carbster09]

Walt, that is the alternative. Going that route most probably means swapping out the old 901 to a 915.

[Hi_Fi_Guy]

I like the way you think Carbster09. I would probably be happy with 180-200hp for this Targa since I mostly treat it as a cruiser and don’t hammer on it... but 250hp in the longhood chassis would be the sweet spot for sure.

[911 tweaks]

What ever you do, work with and buy from very reputable sources so come time to sell car in the future you can have receipts from such that you worked with...

Also, think a bit down the road on what your thinking is regarding the car...
Ie sell the car, track the car, leave as family airlume, daily commuter, resto mid, hot rod car, etc...

Many choices... look and study well to make your Porsche ownership an enjoyable one... Jmho

[Walt Fricke]

Does someone make a 901 flywheel for the 9 bolt crank? If so, you could just use your 901 as is. It is strong enough for a stock 3.0. I have a friend who ran his 2.8RSR clone with the 901 on his 914 and said he didn't have transmission problems. Even with the stock motor I bet 901 owners know not to try drag race starts in 1st gear.

You could run the 911 clutch with the 3.0's regular flywheel. I think you can adapt the 911 release mechanism to the 901 so you'd have a pull clutch, but can't say I know enough about that to be sure - don't both have a ball fulcrum, though the 901 just presses on the fulcrum, while the 911 has to pull against its ball head?

[Trackrash]

Walt, the '70-71 2,2 uses the same clutch as the SC. So the SC flywheel will work with the '70-'71 clutch and trans. I have been told that the 911 trans will handle a 3,0 motor. In fact a friend of mine has a very warm 3,0 in his 914 with the stock trans, and he has yet to blow it up.

Yes, the throw-out bearing and disk are different, but the '70-'71 pressure plate is the same as all the later cars. Porsche started using the flat flywheel in '70 with the 225mm disk.

[Walt Fricke]

Right - same clutch and PP and compatible flywheel diameter/mounting/ring gear etc. Tranny input shaft splines are different than the 915s, so clutch disk has to match? Or did that happen at some other time?

It is the unique 70-71 clutch release lever system which I don't know from experience can just be installed on a 901 case, or whether some adaptation is required.

The cable part I know can be made to work. It performs quite a trick - you use a flexible cable to push, not to pull, a lever. The end of the cable is attached to an extension bolted to the transmission. The Bourdon tube presses against the end of the release lever. When you step on the clutch pedal, that takes the curve out of the flexible Bourdon tube, which causes it to push backward on the lever. The pivot inside causes the other end of the lever, which connects to the TOB, to move forward, releasing the pressure. One hears stories about problems with the lever's attachment to the ball pivot, or the ball pivot itself.

The 915 system looks simpler and more robust.

[jpnovak]

The clutch will work with a 3.0. You need the following.

3.0 225mm 9 bolt flywheel
71 225 911/01 clutch plate
225mm pressure plate. This could be the aluminum sport version
71 type 911/01 throw out bearing installed into above pressure plate.
This will then mount just like the 2.2.

Been using this setup for years. Was driving a 3.2SS with a 911/01 (not gently after first gear) and it seemed to be fine after 7 years.