993 3.6 transplant vs 3.2 build up?

[spsfiend]

I am in the process of trying to decide whether to sell my existing 3.2 and replace with a stock 3.6 993 engine OR build the existing 3.2 up to a 3.4 or 3.6.

I live in CA so I have CA emissions to contend with. I have currently 170K miles on my 3.2. The top end was rebuilt at 98K miles and the intake manifolds have also been ported and polished. It's a great engine and I believe I should be able to sell for a decent price which would offset the cost of buying a 3.6.

Could folks help me out with Pro's and Con's of each approach? Some concerns I have with building up the existing 3.2 is that you are essentially pushing out all the tolerances / limits whereas a stock 3.6 was designed to be a daily driver. This would also leave me room to build up the 3.6 in the future whereas if I were to build up the 3.2 I would pretty much be tapped out.

My car is not a dedicated track car. Its more of a daily driver so I will not be tearing down the engine frequently. I am looking for some longevity.

I did a couple searches on this specific topic and did not find anything specific to this question. I am sure there are probably few threads on this and would greatly appreciate some constructive input. Advice and/or pointing me to some pertinent threads would be greatly appreciated!

[kojo911]

my $.02. I really like the 95 993 motors, I've had both a vario-ram from a 97 and 95. The 95 is an easier fit and you don't have to pay the extra $$ to have the drive bloc removed. The 97 is obd 2 so it's more of a CARB hassle. The only advantage the varioram motors have is a fatter torque curve.

That said these motors are 17 years old and should probably should have the top end done along with rings so budget for that. Couple other points:

-Be sure you are prepared or have a strategy to deal with CARB/Smog. Ca is a pain in the a** a couple of guys on the board have gotten the CARB sticker for they're conversions, check with them.
-exhaust/heat and Catalytic converters. Plan ahead here The stock 993 heat exchangers are pretty good I would stick with them. Some just run the stock CAT with the tips turned down, really loud. You may be able to get away with just the CAT for smog and then make a custom muffler that bolts to the stock HEs for DD. You'll want heat. I live in SF ran no heat in my last conversion. If it's just short jaunts no worries, but drove to SB even with gloves and a lot of layers I froze.

Not sure what a comparable rebuild with cylinders pistons bottom end etc runs these days my guess is its close to buying a 3.6 with a top end rebuild, plus you have to worry about project creep.

[911dean]

I'd be inclined to build a 3.4 or 3.5 from the current 3.2. You will have a brand new engine versus a used 3.6. You could end up with a good 3.6 or you could end up with one that will need work. Building your 3.2 makes the most sense to me, plus the modification involved installing 3.6 won't be needed.

[mreid]

I just went through this decision. I had the stock 133k 3.2 out of my 1984 coupe and considered a 3.5 build right out of Wayne's book. After considering everything, I sold the 3.2 complete and bought a low mileage 95 3.6. I then got completely out of control and installed a pmo efi with electromotive ecu and b&b headers. Shot my budget, but man does it look cool!

[Rodsrsr]

Turbo your 3.2 and be done with it.

[Canada Kev]

Originally Posted by 911dean

I'd be inclined to build a 3.4 or 3.5 from the current 3.2. You will have a brand new engine versus a used 3.6. You could end up with a good 3.6 or you could end up with one that will need work. Building your 3.2 makes the most sense to me, plus the modification involved installing 3.6 won't be needed.

Nah, that never happens...

Jeremy's new to him 3.6 and subsequent rebuild: Well here she is -

[bike2ride95]

Just my 1 cent.. I would build up the 3.2 and have a fresh engine. You can build
the engine with the modifications to make it that much more durable depends
on your funds. Either way you can't go wrong, but a fresh engine is my choice.

[Canada Kev]

Another thing to consider with a 3.2 enlarged to anything bigger than 3.5 is induction. Will the factory motronic support displacements in the 3.7 range if given an appropriate software upgrade?

[JeremyD]

buying a used engine is a crap shoot. An expensive crap shoot.

[midnight911]

went through the question myself, too when my 3.2 lost compression. 3.4 high comp or 3.6? i took the easier route and possibly the cheaper...95 3.6. 3.4 high comp would have better story and way cooler, imo... do it if you can. :-)

[shbop]

There is no substitute for displacement.

[spsfiend]

Thanks for all the input thus far. Would it be easier to smog if I built up the 3.2? Would a built up 3.2 to a 3.6 be relatively equivalent to a stock 3.6 (assuming it was refreshed and nothing wrong with it)? Pro's and Con's?

[midnight911]

Originally Posted by shbop

There is no substitute for displacement.

i respectfully disagree... but i went to 3.6...doh!

[midnight911]

Originally Posted by spsfiend

Thanks for all the input thus far. Would it be easier to smog if I built up the 3.2? Would a built up 3.2 to a 3.6 be relatively equivalent to a stock 3.6 (assuming it was refreshed and nothing wrong with it)? Pro's and Con's?

i think there is no kit to bump 3.2 crank up to be able to handle 3.6 displacement.
3.6 crank and case are quite an upgrade from 3.2.
also 3.6 is much more modern...for example technologies to seal up the oil are more advanced thus less of headaches. valve train also very modernized with bigger valve and better overall design.
from 3.6, you can go as high as 4.1 or bigger...

technically, rebuilding to stock 3.2 is the easiest, if not cheaper, which i think is a cool thing to do.

[pegasus9]

I think about this very thing often.
I always wonder though if i were to make the jump, would it be a not so wise move or would I end up just saying that I should have just gone and done it sooner.

What keeps me from doing it is the fact that I really like the 3.2. And it is just so darn reliable.

[midnight911]

Originally Posted by Slasher

I think about this very thing often.
I always wonder though if i were to make the jump, would it be a not so wise move or would I end up just saying that I should have just gone and done it sooner.

What keeps me from doing it is the fact that I really like the 3.2. And it is just so darn reliable.

cool thing about 911 is that each option is and will be available. rebuilding 3.0, 3.2, 3.6 or doing high comp and higher displacement off those core...or go swap to different motor... all options are available and fairly easy thing to do technically. very unique proposition for 911 aircooled models.

i also wholeheartedly agree with you, Slasher, that 3.2 is a darn good motor and staying with it is another cool thing to do.
i admire and respect any route any person takes, except sending the motor to some wrong rebuilder...just sayin'.

[Fly911]

I have had the same discussion with my self (and several experts) on my ´87 Carrera. I will use the original engine for several reasons, all interfaces will be (more or less) the same, matching numbers car (if that matters), and the engine will look correct in the engine compartment. It will look like a 3.2, but will be something entirely different...
Price wise you will end up north of $10k in both cases.
I will build a 3.8L (or 3.746 to be exact) on the original 930 case. Not a cheap route, way north of $20k, possibly $30k.
The 930 case is just as good as the 964/993 case, used by all Porsche race cars up to the mid 90´s (911RSR, 934, 935, 936, 956, 959, 961, 962 etc, etc).
You will need to twin plug the heads with a higher cylinder diameter than 98mm, and 100mm and 102mm cylinders need to be machined into the case. 102mm (LNE) will give you 3.65L
You would need to extrude hone the air intake manifold ($800), have a bigger throttle body (modified by Steve Wong, $250?), get rid of the "barn door" AFM and get a MAF sensor and conversion kit, and a special tuned chip (again, Steve Wong). For the smog test, you could maybe have the original exhaust with cat and a "lean" chip, and for regular use do a cat bypass and a "performance chip"? I live in Texas and can get away with a cat delete even on my 2009 Boxster! LOL!

[Bill Verburg]

The thing is if both 3.2 and 3.6 need a rebuild anyway you are starting from a better base w/ a 3.6, for street use torque is king and a 3.6 is a torque monster compared to a 3.2, 3.6 starts w/ twin plugs and as long as you stick w/ an OBD1 engine a very efficient and hotrodable engine management package. If you use a 993 you even get a decent exhaust w/ it.

[wachuko]

I would keep your car stock and buy a '95 993... but that is just me thinking out loud....

[JeremyD]

3.6. Has twin plugs. Better chain tensioner s. better intake (plastic). Bigger ports. Better base for a rebuild. 3.6 also has valve guide issues. Gotta vent the distributor. Valve covers suck. Ps and sheet metal needs modification.