912-6 vs 1.9 Benton Build
 

I would love to hear your opinions/ insights on a project I am embarking on (see options below). A 1969 Porsche 912 (original numbers matching engine and 4-speed transmission). The plan? A full restoration with a focus on the body (rust repair, paint, etc.) and a bespoke interior. For context, I also have a 3.2 911 Targa.

Option 1: John Benton 1.9 Build

• Engine: Fun 4-cylinder, 135 hp, revs up to 6800, Webber IDF carb, and reliable (zero-mile engine)
• Characteristics: Momentum car, shedding 100+ lbs compared to the 911
• Build Details: In-house bespoke build with meticulous attention to detail
• Mechanicals: Bilstein B6 suspension, 3.2 calipers, vented & cross-drilled rotors, flex lines, bigger master cylinder, adjustable spring plate, rubber bushings, lower ride height, front and rear sway bars, short shifter
• Timeline: Ready in 18 months
• Cost: $30k more than Option 2 (911 swap)

Option 2: 911 2.4L Swap

• Engine: 2.4L MFI, refreshed 80,000-mile engine (180-200 hp)
• Performance: Faster and more powerful than the 1.9 engine
• Build Details: In-house engine & mechanics, outsourced upholstery
• Mechanicals: 5 speed 901 or 915, Bilstein B6 suspension, 3.2 calipers, flex lines, bigger master cylinder, rubber bushings, lower ride height, front sway bars, short shifter
• Timeline: 6 months to a year
• Cost: $30k less than Option 1

I'm caught between the craftsmanship of the John Benton build and the performance punch of the 911 2.4L swap. What are your thoughts? Any experiences or insights are greatly appreciated! Share your wisdom, and let me know if you have recommendations or considerations I might be missing.

The flat 6 sound track is so much more intoxicating, that alone is reason enough for me.

Have you also considered a Wilhoit motor or a Polo motor?

Not for the purist, but a type 4 in a 912 could be cool too. Porsche did build 912's like this of course, and it would bolt right up to your 901 trans. And you could get 200 hp from a larger displacement one for less than a full Porsche tax motor.

What's your intended use case?

What size & type tires will you run?

What's the difference in curb weights and lbs / HP?

Soundtrack is indeed important and an additional ~55hp & X torque is always nice, but lightweight is a specifal thing, not to mention a rarity. Revy is fun too.

Sounds like a fun project.

I plan to use to enjoy it as a GT cruiser and rip it on the backroads here in California.

I plan on running 15s, 6s up front and 7s in the rear. Haven't decided on tires yet, but probably 205/55

I am unsure of the exact difference in curb weight, but the 912 would be 100-200lbs lighter. Horse power would be 135hp vs 180hp. I don't have exact torque figures. The Benton will rev up to 6800 rpm and the 2.4 I believe will rev up to 6500ish.

I've considered both. The Polo motor while a work of art is out of my budget given the overall project. The Willhoit motor, is a great engine with a lot of engineering thought and testing put into it. It's definitely an alternative.

The rear weight bias of a 6 vs 4 cylinder will affect handling.

Compare power to weight ratio between both packages to help your decision.

I had a 912E and a ‘75 911 with a 3.0L with the same suspension setup and the same wheel and tire package that I autocrossed at the same time.

The 912E was less controllable on the limit because it didn’t have the power to drag you out of trouble. The 911 you could catch and hold some wild oversteer excessive trail brake moments because it had the power to drive out of it when the 912E would just bog down and spin.

Is this comparison relevant to a conversation about a 1969 where there will be a considerable increase in power with either provided option?

I think it holds true. More power of a 6 more than makes up for the weight penalty and you get dry sump oiling and it sounds better and the OP is saying going with a -6 will cost less?!

Sounds like a no brainer.

Like others have said, light is delightful. At the price of a Benton special, I would vote for a Type 4 engine to keep it significantly lighter than a 911 conversion (and besides, you already have a 911), not to mention a whole lot cheaper, and probably stronger too. And find a 901 5-speed while you're at it.

I built a Type 4 2.4 for a 1974 914 I used to have. It was a blast.

I agree with Pete. It is 912 do not put a 6 banger in it, use a type 4 VW and build that to the moon for next to nothing. It is so cheap you could screw it up all you want and still have money for the next hoonmotor..

Or put a Mazda 13B 2 rotor in it. New motors from Mazda are 8000.00, 195 Hp, 9000 RPM, very, small light weight, reliable for the first 100K miles, 3 moving parts, smooth as silk..

...and sound like a trio of chainsaws! I had a Mazda Rx-7 for a few years and I liked that sound. It's definitely different.

Rotaries are cool, not necessarily for a Porsche purist though. And get your earplugs, they will make your ears bleed.

Sounds like Benton would be responsible for the entire build? He definitely has the recipe for spicy, well balanced four banger hotrods... and since you already have an impact bumper car to drive in the meantime, I think it's worth the wait.

The difference in a 912E and mid-year 911 with a 3.0 transplant is vast compared to the difference in a stock 1969 912 and 911.

The 1969 912 had a 1.6 carried over from the 356 and around 100 hp. Don’t recall the torque numbers. The 1969 911 obviously had 2 more cylinders, but only an extra 0.4 L of displacement and 30 or so more horsepower. *Edit- for the sake of argument and addressing the information provided by the OP, the 2.4 L will of course have 0.8 L and 80+ more horsepower than the 1.6. So, in that respect, your comparison makes more sense. However, the 1.6 will gain displacement and power.

The mid-year cars were heavier than the F Body and the 912E had a VW sourced 2.0L with even less power than the 1969 912, not too mention Hal the power of a 3.0 L.

I’m not saying the OP should go one way or the other, it’s just that comparing two vastly different G Bodies to two more similar F Bodies doesn’t add much to the debate.

Judging by the op, the 2.4 swap would be S spec??? Because the 2.4T was like 140 hp, not 180-200 and MFI.

I think what makes more sense is to determine a desired hp/wt and then factoring the costs/reliability to get there with the three options.

I am mistaken about the horsepower figures of the 2.4. If kept a 2.4 it would be an E spec engine. There is also the option to bore it out to a 2.7


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