Value of swaps: 2.7 vs 3.0 vs 3.2 vs 3.6

[RallyJon]

I've been reading about various 911 engine upgrades, planning ahead for a horsepower injection for my '71. What stands out most to me is how (roughly) comparable in price the options are. A rebuilt 2.7/915 swap is no where near as cheap as it should be, relative to a 3.6. This makes very little sense. A freshly rebuilt 2.7 or SC motor costs as much as one from a 964, and you still have to work out the kludgy induction options, while the 964 motor has bulletproof, tunable EFI.

Further, an "R Gruppe" style swap seems to add real resale value to an older 911, with the larger displacements adding proportionally more value. A simple rebuilt 2.7 with CIS or Webers wouldn't add much value at all.

Obviously, when we're talking about these sorts of swaps, originality is out the window. These are for "drivers" only.

For example,

Option 1:
964 motor - $7000
Adapter kit - $1500
260+ HP, amazing torque, perfect drivability.

Option 2:
2.7 rebuilt to RS spec - $7000+
MFI to RS spec - $2500+
or
PMOs - $2500
or
Tec III or similar EFI - $6000+
220+ HP, peaky power curve, tempermental drivability.

Why is there such a huge disconnect in the 911 engine market? Shouldn't the (relatively) cheap and available newer motors be driving the 2.7s and SCs prices way down? And if not, why not?

[Rick Lee]

I agree with you. But some folks want to keep their 911 original. And I think an engine swap will also affect which class you can race in, if you're a track person. I have no qualms about adding non-original parts to make my 911 better, stronger, faster. A 3.6 it is!

[AES]

There are different kinds of buyers. Some only want matching #s and unmolested examples, others want mods , but to a rule, still others are free to do whatever they want in the hot rod spirit. I think that the cost is comparable because labor is labor and parts is parts. Each owner needs to decide what his vision and constraints may be, then go for it.

[Todd Simpson]

Pano has a 996 engine for sale in the classifieds at $5500, while Moses has a 3.0 SC for sale that he's been offered $5000 for.

There are too many factors here that change things. One engine is rebuilt, the other is not. One is a pretty simple bolt in for an early car, the other requires lots of additional work matching wiring, beefing up the trans, mounting flywheels sensors, etc. etc. We've all had the project that kept going up in price and yes, maybe $1000 more will give me another 50HP, but you gotta stop somewhere. But other than that I can't explain it any better than you can. It's just "the market."

We've got several nice RS replicas at the Schattenbaum region track events, looks like 3 of them will have 3.6's next year. The owners would be happy to tell you what it took to make it all work. Mine will be continuing with 2.2S/901 combo for at least another year.

Here's a 3.2 (soon to be 3.6) following a 3.6 in a '75 Carrera.

Oh, BTW, what do you have now?

[RallyJon]

I understand that if you have a nice, unmodified car with matching numbers, you rebuild your stock engine and pay whatever it costs.

My interest is in performance and feel, not necessarily raw power. Right now I have a 2.4E with Webers and headers. It makes a pleasant amount of power, but is definitely not fast. The carbs sound great, but other than that have no redeeming qualities. It's low compression, which is great if I want to run 87 octane, but why would anyone do that?

What I want is to get some more power, really anything over 200HP is enough. But when I start looking at having my engine rebuilt to make that power, the math quickly stops making sense.

The Webers (which were tuned up this spring by a reputable shop, btw) have got to go. With the great throttle response and seamless performance achievable with fuel injection, it's a no-brainer. EXCEPT that putting even a simple EFI system on an old 911 motor has a price wildly out of proportion to any other vehicle.

For some reason, later engines sell for much less than the sum of their parts. But parts for early engines cost much more than the benefit they deliver.

[Jack Olsen]

We're in a great window for the remaining low-mileage 3.6 motors right now, but it won't last. They're getting older, and they're not cheap to rebuild.

The disadvantages of a 3.6 swap are:

You lose the originality of the car's powertrain.

Getting work done on the car can be a little more difficult, since it's no longer in its stock configuration. (Of course, the same goes for a hot rodded 2.7.)

You can get penalized in race group classification systems because your motor displaces more than stock.

The advantages are too many to list.

[chuckw951]

It sounds to me like you want to be convinced to do a 3.6 swap. If you have the resources, then by all means do it. More HP is always a good thing.

Myself I'm installing a 3.0 into a 69 911. It will have SSI and CIS. Total cost should be around $5K including a top end rebuild of the 3.0 motor.

CIS is not a bad word! It is an inexpensive, reliable FI system. Go with a 78/79 intake system, 80-83 motor (9.3 to 1 compression), free-flowing exhaust (SSI or headers + muffler) and IMHO you have a pretty sweet set up for an early car.

Take the extra $5-7K and buy a 914 2.0 to drive when the 911 is in for service!

Chuck

[CamB]

And you gotta cool the 3.6. If you don't like front mounted coolers (Jack!) this is a fair bit of work.

You missed the "put a 3.2 in it" option. They have a little over 200hp (or closer to 230 if Euro) and more or less bolt in.

Plus there seems to be a real line you cross around the low 200hp mark where it starts to become essential to upgrade the suspension and braking in line with power. I actual think my car is overpowered now (270hp and narrow tyres).

[RallyJon]

Actually, Chuck, I'd rather be convinced that I could do what you're doing for $5k all inclusive. A $2000 rebuild seems like a pretty remarkable deal--your guy seems to be a rare resource in the universe of 911 engine builders.

[rcwaldo]

is there a huge weight difference between a 2.7 and a 3.6? I am curious because the 3.6 used thermoplastic where it could. I dont know the engine weights off the top of my head.

Chris

[chuckw951]

Originally posted by RallyJon
Actually, Chuck, I'd rather be convinced that I could do what you're doing for $5k all inclusive. A $2000 rebuild seems like a pretty remarkable deal--your guy seems to be a rare resource in the universe of 911 engine builders.

I'd be happy to pass on his name and number. Keep in mind that's $5K out of pocket and I had a 2.0 911E motor to trade. You have a 2.4E motor to trade if you wanted to. Someone doing a 914-6 swap would be interested in a 2.4E motor or perhaps someone that wants to build an RS spec motor. I can send you a breakdown of the costs. With that said I would be reluctant to buy a used motor that I wasn't going to rebuild. I mean if you have a '81 SC motor or '86 3.2 motor with 80K miles, what do you really have. Those head studs on the '81 motor could snap at any moment and well, we've heard stories about the valve guides on the 3.2s. Again the 3.6 sounds great (as a motor and as a project) but whew that's alot of cash.

[Bill Verburg]

I agree with Jack's comment about the window. When I did my original 3.6 transplant in 1994, I started out looking for a 3.2, but there were no acceptable ones around, low milage 3.6 964s were cheap and plentiful, as no one had a need for them at that time. Since then the transplant idea has caught on, there is now a demand for all of the available 964/993 engines and the price has gone up. The same thing will happen to 3.6s the supply will dry up, but this time there isn't a better transplant alternative around.

As to the price, an engine builder doesn't care whether its a 2.7, 3.0, 3.2, 3.6 or 3.8, the same or comparable parts and labor are involved for any rebuild. The 2.7 may be even more expensive due to the additional need for case savers which the others don't need.

Arguably the best bang for the buck is a 3.6 transplant, as long as you are starting w/ a 72 or newer car the costs of a transplant are roughly the same but do decline as the age of the chassis decreases. The reasons are many, among them are oem flares, oem trans. notches, oem voltage regulation compatible w / 964/993, oem oil cooling w/ a larger capacity, oem brakes which have a higher capacity etc.

The other thing that is often forgotten in discussions of this nature are the torque curves and the drivability of the cars. I have friends w/ 250-300 hp 3 and 3.2 liter race cars which need 100 octane race gas and only operate comfortably between 5-7500rpm. For a race car this is fine but if 90% of your driving is on the street it is unacceptable. I could have purchased for only a little more $ than my 3.8 RS a 3.8 RSR which would have been in the above catagory, not acceptable to me(but great bragging rights)

[JonT]

Bill--can you explain what you are doing with your engine, what alternatives you were researching and why you chose to go with the 3.8L? What kind of power increases are you expecting? We're all curious! Thanks

[Bill Verburg]

I started out looking for some cams for my 964, after hours of chatting w/ as many knowledgable folks as I could and looking at options from a Daytona placing 993RSR engine(2 available complete for $30K and $24k) down the food chain, I eventually got a very good deal on a set of 993RSR p/c which I decided to build around. A '97 993 OBD1 varioram was purchased and the rest will be determined over the coming months. I am hoping for north of 300, but far more importantly (to me) a nice FAT torque curve to better match the gearing and tires which I want to use.

I wanted to act now as the supply of suitable engines is limited and everything just sort of fell into place.

If the RSR p/c hadn't shown up, I am sure that the original plan of some cams and port work would have been almost as good for a lot less $$.

[Lewis Ledyard]

I am putting a Euro Vario 993 3.6 motor in my '88 cab. Steve Timmins is doing the work, so a remapped chip, custoim exhaust HD clutch, LW flywheel and additional oil cooling are part of the package. Are there any mods other than 3.8 p/c or forced induction that could/should be done to boost the performance of that engine?

[dd74]

My upgrade to a 3.0 cost $5k with the 2.7 in trade, but that also included installation.

The 2.7 was quite strong, but leaked and rattled in places that precluded having the 2.7 rebuilt in a cost-effective fashion. In short, $6k to rebuild the 2.7; $8.5k to have the 2.7 rebuilt RS style. The 3.0 had very little mileage on it, and was completely stock, which also attracted me.

I considered many, many other options, including a 3.6 and even a V8, but thought again about the consequences of such big hp in a relatively light car.

It's for that matter that I would take in earnest what CamB and ChuckW951 say. A 3.6, IMHO, means enormous additional upgrades to many other components of the car. Oil cooling is just the start of it. Brakes are crucial as possibly might be the transmission.

I even asked the mechanic who installed my 3.0 about doing a 3.6. He told me straight up that his 3.6 transplant didn't last more than fifty miles before he blew his 915 gearbox.

I don't know if going much over 200hp is stretching the limit of early and mid-year 911 cars - I don't truly want to find out. But I do know the money you save can afford you many other upgrades to your car.

My upgrade was going to Maui.

[Tinker]

DD74 makes some good points, as does Bill and Jack. I swapped a 3.6 into my 72 back in 1997. Is was a fun car at the time, but there was a bit of a learning curve, ie the cooling, brake and trans problems. Once sorted out, it has been a blast. BUT, as Jack mentioned there are liabilities to having the big motor especially if you plan on doing any club racing where you are HEAVILY penalized.

For a daily driver, I think the 3.0 and 3.2's are great cars. Driven/built many of them. On the track, I find the 3.2's in an early car to be almost as quick.

As Bill is experiencing, the rush of the 3.6 wears off pretty quickly and your always looking for ways to go faster. If you really want to go fast, drop a turbo motor in it. I think Jack will attest that the 3.6 might be quick, but a turbo in an early car is a whole new demension.

Tinker

[nostatic]

I'll still argue the 3.6 is a potential false economy. If you rebuild or build out your known engine, you can have confidence that you're good to go for another 100K. If you buy a 3.6 motor, you could be in for a rebuild sooner rather than later. I think you have to factor that into your financial scenarios.

[AES]

Transplants are like anything else, sure lots of things can go wrong, I've seen new rebuilds that needed immediate re-rebuilds due to negligence/accident or just bad luck. Due diligence is necessary. I don't think that the bang for the buck in a 3.6 transplant can be debated. I sure am consideribg it for my '86.

[Joeaksa]

Jon,

The large question is: are you going to keep your 911 forever or is it an interim car?

If you plan on keeping the car "forever" or a very long time, then the swap IMHO is not a question if you feel the need for a large increase in HP.

If the car may be sold in the next year or so then I would keep it as orginal as possible as the value would be better than with any transplant.

I am very happy with my car and it just might stay with me the rest of my life, so I could care less about resale value. If you feel the same way about yours, then the window is open on mods you make.

Joe