cost of 3.2L upgrade vs. EFI swap on a 3.0

James Brown · James Brown's Garage

I'm looking at upgrading the CIS on my sc to a more modern EFI or carbs setup and wondering if it's worth all the trouble of finding the right parts for a conversion (EFI or carbs) or just swapping out a 3.2L monotronic engine and selling the 3.0. I think the price of a good 3.2 is around 4-8k and the selling price of my old 3.0 around 2-4k. vs the cost of going with PMO's or Weber's or a monotronic setup. anyone have any numbers that might sway me? Carbs are cool but daily driving is a concern. Not a track car. Any thoughts?
1981 911SC

Phil Blacklock · Phil Blacklock's Garage

Save your money, stick with the CIS. (IMHO)

smokintr6 · 04:49 AM

$8K would put you in the neighborhood of a 3.6L, which would probably be worth the effort. I have seen some 3.6's selling for less than $8k lately. Remember when doing conversions, you are on a slippery slope. You may find brakes and suspension inadequate afterwords, and you may spend some extra $$$ doing any conversion. It's the unplanned details that will get you. The other problem when doing an engine swap is that you are dealing with a large unknown...the new (used) engine. I have driven 3.0, 3.2, and 3.6 powered mid year cars... If you are going to spend the time and money to do a conversion, go 3.6. In the long run the 3.2 is probably more effort than it's worth. If you were dead set on having a 3.2L torsion bar 911, it would be much easier and cheaper to sell your SC and buy an 84-86. In this economy there are also some killer deals on G50 carreras as well.

Doug&Julie · 06-05-2009, 04:46 AM

Quote:

Originally Posted by smokintr6

...The other problem when doing an engine swap is that you are dealing with a large unknown...the new (used) engine.

+1. This is what has kept me from considering a 3.2 swap. My 2.7 is strong and runs well, I just want to get rid of the CIS. More than likely I'll end up with an EFI conversion.

Having said that, from a pure cost standpoint, you can probably sell your 3.0 for pretty close to the cost of a 3.2, so financially it might be worth it to "trade up". Of course, you have to consider the in$tall as well...

Shaun @ Tru6 · 06-05-2009, 05:08 AM

Good used 3.2s are plentiful and the job is done in one weekend. Buy a $5500 motor with good leakdown numbers and plug and play for another $1000 at the most. Assuming you have good leakdown #s, no broken studs, sell your motor for $4K.

Conversions are OK, but take a lot of time to get right.

A 3.6 is a $14K endeavor and your brakes won't be up to the task.

PcarPhil · 06-05-2009, 05:18 AM

I'll suggest being patient and finding the right 3.2 to swap in. Ideally you'll find one with good leakdown (and compression) numbers and maintenance history. Even better it'll still be installed in the car so you can see it running (perhaps that person is upgrading to a 3.6 or the car was recently in a front end accident and will be parted out).

$5k - $7k should buy you a very nice complete 3.2 engine (engine, DME, wiring harness, rear fuel lines). Then sell your complete 3.0 for $3k - $5k depending on condition.

Add a SW chip and good exhaust and have fun!

Edit: Don't sell your 3.0 until you have the 3.2 installed and running well!

PcarPhil · 06-05-2009, 05:28 AM

Quote:

Originally Posted by smokintr6

If you were dead set on having a 3.2L torsion bar 911, it would be much easier and cheaper to sell your SC and buy an 84-86. In this economy there are also some killer deals on G50 carreras as well.

That's a good point. A friend called me the other day mentioning a local '84 Carrera with ~125k miles for sale for $12500. White with burgundy interior in good shape.

Selling your SC and buying a Carrera is another way to do it....but if you really like your SC, and it's in good shape inside and out, then doing an engine swap is a fun project.

The only big reason I'd consider swapping a CIS 3.0 for a Motronic 3.2 is for the Motronic system. IMO for everyday driving the Motronic system is easier to get along with.

If you're looking for a huge power increase over the 3.0 then skip the 3.2 and go for a 3.6.

Horrido · Horrido's Garage

There is an article in Excellence #167 September 2008 page 165 describing a conversion to EFI using the Bitz Racing kit. Interesting reading.

MrPerkles · MrPerkles's Garage

I have just put EFI on a 3litre and it transformed the engine the throttle response is insane but it wasnt cheap even though I DIY
I think people are missing the point about swapping with a 3.2 as they are very different drive to a 3 litre,unless your are happy with that

Doug&Julie · 06-05-2009, 06:19 AM

Quote:

Originally Posted by Horrido

There is an article in Excellence #167 September 2008 page 165 describing a conversion to EFI using the Bitz Racing kit. Interesting reading.

That's what inspired me to start thinking about replacing mine. There's a lot of discussion on this board about it as well. I tend to fall into the camp that thinks CIS is going to be harder and harder to find parts for / fix so it would be wiser to spend the money on an EFI upgrade.

PcarPhil · 06-05-2009, 09:09 AM

Quote:

Originally Posted by MrPerkles

...I think people are missing the point about swapping with a 3.2 as they are very different drive to a 3 litre,unless your are happy with that

How so?

In my experience a stock 3.2 doesn't have the low end grunt that a 3.0 has but the 3.2 has better upper end.

Add a SW chip and cat bypass to the 3.2 and now it's got the low end of a 3.0 and plenty of upper end as well.

Just my $0.02.

MrPerkles · MrPerkles's Garage

Quote:

Originally Posted by Kaefer

How so?

In my experience a stock 3.2 doesn't have the low end grunt that a 3.0 has but the 3.2 has better upper end.

Add a SW chip and cat bypass to the 3.2 and now it's got the low end of a 3.0 and plenty of upper end as well.

Just my $0.02.

Not kncoking either engine ive had both I just prefer the 3 litre and if it was mine would enhance it rather than put in a 3.2

James Brown · James Brown's Garage

Thanks, all great points, I like the 3.0 and the CIS is working very good just getting long in the teeth. looks like a EFI like bitz racing and a set of SSI will be the ticket.
now, about the 915 tranny... rebuild or G50? both have there quirks (I don't have 1st or 2nd syncros but have learned to shift correctly to overcome this) Lots of posts about rebuilding and it's not TOO spendy. Can't see any real advantage with the G50 over a good 915, any comments?

ljowdy · 06-06-2009, 04:05 AM

James Brown (That name is difficult to say without shouting "I feel good!!!!")

read this: http://www.pelicanparts.com/MotorCity/marcesq1/

stlrj · 06-06-2009, 04:48 AM

Quote:

Originally Posted by MrPerkles

Not kncoking either engine ive had both I just prefer the 3 litre and if it was mine would enhance it rather than put in a 3.2

I've had both too and I also prefered the 3.0 until I discovered how to manipulate the mixture on my 3.2 that now runs circles 'round my old 3.0 off the line.

yelcab1 · 06-06-2009, 04:56 AM

If it were me, and I wanted more out of my 3.0, I would toss out the passenger seat, spare tire, carpet, AC, rear seats, sound deadening material, get ligher wheels, and just have more power to weight ratio. CIS, well, I can deal with that.

If I really wanted to have easier to deal with ignition, then I just sell my SC, and buy a 3.2L carrera instead.

But, that is just me.

stlrj · 06-06-2009, 05:43 AM

Quote:

Originally Posted by yelcab1

If I really wanted to have easier to deal with ignition, then I just sell my SC, and buy a 3.2L carrera instead. But, that is just me.

Then why not get rid of the CDI and convert it to an OEM style conventional system?

kenikh · 06-06-2009, 08:24 AM

The best money you will spend is converting to TBitz EFI, and getting new cams and 9.5:1 CR pistons. That combo will run circles around a 3.2 Motronic and should set you baxk about $2500 in parts. Fast revving, totally compliant and more satisfying than the other options.

911st · 06-06-2009, 08:25 AM

Doing things like changing induction systems, swapping motors, and even selling and rebuying car is always time consuming and more expensive than you will expect.

A well tuned and running SC with CIS is a wonderful car that can even put a 3.2 Carrera down.

Spend the effort on the tires, suspension, brakes, lightening the car, and increasing the drivers skills. You can go a lot faster doing this than adding HP.

Having said that. If intent on mods. A 3.0 is a very solid base. Add a set of PMO carbs for about $4k and a good sport exhaust and you will have quite a Porsche experience and be set up for things like a 3.2 short stroke with aggressive cams that is a very fun motor.

Just note that such expence if luckly will only return penneys on the dollars and limit your market if you ever decide to sell.