72 911 Engine Debate

[Ben M]

Wayne,

I've read your book and now have enough knowledge to be very dangerous.

I own a 72 911T that I'm converting to a RS look. I've upgraded the suspension and brakes (big reds..wow what braking power). It has a 2.4 engine with webers with one cylinder at a 24% leak down, so my choices are to;
A: Rebuild the 2.4 to a 2.7 or 2.9.
B: Purchase a 3.0 and re-build in a few years.
C: Purchase a 3.2 and re-build in a few years.

I've gotten rebuild prices from $8,500 to $15,000. A used 3.0 or 3.2 priced at $5,000 to $7,500, but will be faced with a rebuild at some point in the future. Not planning to sell the car and it will be used 75% street and balance on the track, Porsche driver events, etc.

Oh, Whats my 2.4 engine worth?

Truly appreciate your advise.

Ben

[afterburn 549]

if you can do the work hot rod the case and go the route you want. By that I mean put in all the latest and greatest up dates.......dowl pin and vent it , along with the case savors and stufffffffffff

[Bill Verburg]

For street use torque is what you want, I would go w/ choice (C)

If you are going to race you are already in trouble because of the brakes.

[Jay Auskin]

Talking sale price, your 2.4T isn't worth too much as a whole (~$2000-2500). Parting it out would get you more. From a rebuild standpoint, a 2.4T is a good canidate because it has had a very easy life...unless it's on a few rebuilds. The $8500-$15,000 is way out of line for a rebuild. As mentioned, do it yourself, upgrade it to the hilt, and save a bundle. Even if you don't own a single wrench, you'll still come out ahead. Do a search on 2.7RS engines, and you might get some ideas

[Wayne 962]

Before I answer your question, I need to know what you're planning on using the car for (street / track). What are you looking for?

-Wayne

[Grady Clay]

Ben,

Personal Mail (PM) Pelican member in this forum “rs911t”. He has a similar situation as you with a now high compression 2.8S in from a ‘72T engine. He can offer some first hand perspective.

I agree with Jay and Afterburn, rebuild your 2.4T with all the latest stuff. There is 30 years of experience with that engine available, much on this Forum.

A Pelican search with keywords: 2.7RS, 2.8S and the like is a good starting point.

Another consideration is that your ’72 is very light weight. Adding a later (heavier) engine reduces that advantage. A carbureted 2.7RS or 2.8S are as light as you can reasonably get and have great performance.

Bill is referring to your 25% track time. If you want to compete (as opposed to just drive for fun) then you need to pay attention to the various rules.

Best,
Grady

[Ben M]

Thanks very much to all for your advise.

I'll have the time this winter to re-build, so that's a great option. I will definitely do much more research.

The brakes (to me) are worth it even if it means getting bumped a class, high performance brakes are as important to me as the engine.

Thanks Again, Ben

[jgparker]

I second the HC carbed 2.8RS option. A great fun engine, and true to the early cars. If you have to ask what the gas milage will be, it's not the engine for you. The Aluminum S-breaks are a nice incremental improvement, without going overboard.

good luck,

JP

[Henry Schmidt]

I would build a high performance 2.4. You just bore your cylinders .040 oversize and buy a set of JE pistons from our host PP and you can make as much power as you want.
One example might be:
9.5 to 1 pistons, some mild porting, Solex cams ("S" if derivability is not as important) jet the carbs and you'll have 200 hp more or less. It's the most cost effective and you won't encounter some of the 2.7 problems. Remember with over 160 hp you'll need a front cooler.