okay what is the word on the displacement increase for 3.0 SC

[82SC]

Alright I wanted to start a thread so the SC owners can come back to when doing there engine rebuilds....

one of the best mods is the displacement increases...but as with all porsche topics the advice varies ALOT

so let me put out what I have heard and know...feel free to correct me...with Warren, Roland, Leland I am sure we will have great info for future rebuilds


Well Bruce Anderson has said...
replace the pistons and cyliders same compression and get an honest 220hp

I have heard just changing the crank to a 3.2L crankshaft from the Carrera can make the engine a 3.2L as well (some say just the crank...others say more parts are needed too, but I know of an engine with just and new crankshaft and nothing else) I think there was some discussion of a short stroke and long stroke 3.2L engine...what are the benefits and disadvantages?

Then we have RLJ's Iris with the 3.2L Carrera heads but which p&c's??
are the Carrera p&c's usable on the 3.0L SC block???

Then we can get into high compression 3.0L p&c's like the 3.0L RSR
And even 3.2L high comp p&c's
Of course this requires racing fuel or twin plugging

I am hoping to hear detailed info about people's experience with this...and their results...which parts were reused...which are new...

I am envisioning a twinplugged 3.2L high comp engine with hotter cams as my dream engine

Is a swap of the CIS system required...I like carbs, but I want a daily driver engine as well...and I have heard carbs are finicky...and passing emmissions may be a dream after carbs

Best combination of daily driver and occasional track use...

[Jack Olsen]

Randy's is a great model of where you can take an SC motor. But smogging a modified SC is always going to be tricky. In fact, it's enough to make a guy go find a nice pre-1974 long-hood car...

Then again, a 3.6 in a 73 isn't technically legal, either, but the state doesn't have an annual chance to catch you.

For what it's worth, I think the SC is about the best looking of the 74-89 bunch.

------------------
Jack Olsen
1973 911 T (3.6) sunroof coupe
jackolsen@mediaone.net

[82SC]

hey anyone???

Come on I know Roland has at least 3 screen fulls of much needed knowledge

[Bill Verburg]

There are 2 ways to increase the displacement of your 3 liter.
1)Bore, to do this you have 2 choices use the 98 mm Mahle piston and cylinder set(often referred to as the Max Moritz pistons) or buy a set of 98 mm pistons from JE and have your cylinders reworked by someone like EBS, Both of these options are expensive with the Mahle option being the most so, but also the more desireable. If you go this route there are different piston crowns to decide on, one is for stock CIS and a different design is for carbs/MFI so you need to make that decision first. The 98 mm pistons used with the stock SC crank gives ~3.2 liters of displacement.
2) stroke, the 84-89 3.2 liter Carrera crank can be used in the SC block, this also is expensive and gives the same displacement as the Carrera ie ~3.2 liters, a complete 84-89 crank, rods, piston, cylinder setup can be transplanted
3) you can also combine both option 1 and option 2 for ~3.4 liters.

The problem with all of the above is that they are expensive and you will have to engineer the systems involved. Most people seem to swap rather than rebuild, this also is expensive but in general you know exactly what you are getting when done, and will update your other systems, such as electric, and FI. Swaps are also expensive but generally less so than custom rebuilds with non-stock parts.

[atr911]

I hear what you are saying...

I have the 98 mm (3.0 to 3.2 conversion) cylinders and I'm shopping around for some high compression (10.5:1) pistons to use. Twin plugging is a MUST and I think I'll be looking for a used Electromotive setup.

This is what I decided to go with for my performance upgrades. Weber or PMO carbs are also in the future.

Cams will need to be upgraded to be more aggressive and fit the new engine.

All in all, I hope to be putting out somewhere between 250 and 300 true horsepower (It'll probably be set up for acceleration as opposed to top speed)

Good luck with your project!

Adam Roseneck

------------------
1978 911SC 3.0
roseneck@cyberbeach.net

[Formerly Steve Wilkinson]

Why do people say 98mm cylinders are the only option for the 3.0? I put 100mm Mahle p/cs on mine and it runs just fine.

stephan

[Early_S_Man]

The 98 mm cylinders fit without modifications to the block, whereas 100 mm cylinders need the block spigot bores to be enlarged.

------------------
Warren Hall
1973 911S Targa

[hank911]

Just got done with a web cam 20/21 upgrade on my 83SC.Also had a the intakes "boattailed" while freshening up the top end.Also added a lightened presure plate and SSI's.The power the car makes now is awsome.Second gear pulls strong to about 75mph.The car also starts pulling much harder at about 3000rpm now and spins up considerabley faster!Mucho fun to drive!!!!

[Bill Verburg]

The 98's were the first ones available, In Europe they were a favorite mod right off the dealers lot because they required no case machining and only a slight head chamfer but no other mods(at least if the proper CIS piston crown was used with ~9.5:1 cr). If the 98x9.8:1 cr was used a switch to carbs or MFI was required.

Here is a short summary of what's available;

1)for 3 liter case with 22mm wristpin, on 70.4mm crank; 98mm (3.2 liter),22x61mm w.p., cr 9.8, no case machining, head chamfer
or 98mm(3.2 liter), 22x58mm w.p.,cr 9.8, high dome, MFI/carb, install as previous or 100 mm(3.3 liter), high dome, 22x61mm w.p., cr 9.8, case machining and chamfer required, twin ignition recommended.

2) For 3.2 liter 23 mm wristpin, 74.4mm stroke crankshaft; 98mm(3.4liter), 23x58.5mm w.p., cr?, wedge dome, no case machining, head chamfer, DME or 100mm(3.5 liter), 23x64mm w.p., cr? ,wedge dome, crankcse machining required, head mods, twin DME ignition recommended

In addition the 3 liter 70.4 mm crank can be swapped for a 74.4mm crank. There is even a 76.4mm crank (3.6 liters with the 100mm pistons) available for either the SC or Carrera block.
I keep coming back to the fact that a factory engineered engine swap is the optimun solution unless you are building an all out race car.



[This message has been edited by Bill Verburg (edited 06-04-2001).]

[Wayne 962]

Nothing corrupted here about the BBS...

-Wayne

[Bill Verburg]

Thanks!!

[RLJ]

Hi guys, I used my Alusil cylinders bored and sleaved to 98mm (thats why we went bigger displacement, we had Alusil cylinders and would rather bore and sleave than buy Nicasil, buying pistons anyway) with J_E pistons orderd at 10.5:1 and after finial fitting, polishing, and buffing ended up with 10.25:1. With Dual plug the motor wizard says this is the limit on compression for West coast gas. The heads are 1988 Carrera 3.2. That was for the port size and a little better combustion chamber design than the SC heads. Also cause he had them on the shelf, already dual plugged and ready to go.

My motor wizard says that the long stroke 3.2 makes more torque than the short stroke version, when all else is equal. The short stroke motor makes revs faster that the long stroke, and with an aluminuim flywheel and pressure plate "Iris" spins up like an electric motor.

Remember ther are more than one way to skin a cat!

Randy Jones
1971 911

[82SC]

sounds like the fuel system is something that has to be decided pretty early on...

Being in SoCal keeping the CIS sounds like it is essential to pass emissions??? is that true?

so it sounds like the piston shape and cams are dependant on the CIS...is there a way around this? like a piston cyl heads cams combination that adds punch but works with the CIS...and maybe will be able to adapt to carbs once the car becomes a smog-exempt car or a track car?

(I want to up the car to 3.2L keep the CIS with the hope of upgrading to carbs or slide throttle, double plug the heads, hotter Cams, SSI exhaust)

Thanks

[Bill Verburg]

All of the big bore kits will increase hp and torque when used with cis. Torque more so than hp, the CIS limits high rev air flow, since you live in So Cal and must pass emissions inspections (at least for a few more years) and are probably going to be limited by exhaust and cis, I would try the following
*98mm (3.2 liter),22x61mm w.p., cr 9.8, no case machining, head chamfer,CIS pistons
*964 cams
*arp or raceware hardware, especially headstuds and rod bolts
*late cis fuel dist(you could also try a turbo cis fuel distributor)
*84-89 exhaust headers and cat(if required), if the cat is not required but a visual inspection is likely gut the cat, be sure to clean the inside thouroughly(try to smooth it as much as possible), I think a 964 exhaust and cat might fit but i'm not sure about that(it would certainly flow a lot better than the 3 or 3.2 stuff.
*twin ignition is a nice plus
*if money is still available a 74.4 mm crank and rods, this will require different pistons with the larger 23mm w.p. so plan it out before doing anything.
The above will give you a nice torqey engine which is what you want for a street car.
I would still urge you to swap in a 964 or 993 ala Jack Olsen or myself. With a 3.2 exhaust as Jack used it could still pass a visual(maybe).

[82SC]

Great info!

Thanks

Which is more cost efficient?
Buying a 964 or 993 for about $6000 with miles on it...make a bunch of mods to the car to accept the engine...I am assuming I am keeping the 915 so a late 964 or 993 is probably not possible (??)
So al included I am assuming 7000-9000 to put in a used 964 engine

Or redo the engine?
I am assuming 2000 just for the rebuild and an additioal 3000-4000 for parts and machine work...(I am hoping to do the rebuild myself, I think I can do the rebuild myself with the help of you guys...but the mods to adapt a 964 engine will definately have to go to my mechanic)Then I will have a engine with no miles on it...but be stuck with an outdated CIS...

Just wondering which is more cost efficient..

[Bill Verburg]

The 98 mm piston/cylinders alone will set you back close to $3000 unless you get a great deal.
The biggest obstacle to a swap is the wiring, when I did the 93 into my 76 there was little info on the subject and it was closely held(proprietary). Steve Timmons ( http://instant-g.com/Cars/index.html ) for a very resonable price sells everything you need for a swap including info, Patrick Motorsport is also a good source for parts.
The 964 or 1995 993 swap is straight forward, 1996 on runs into the OBDII hassle.
they all use the 915 and stock clutch/pp you will need to buy a flywheel, the exhaust can be a stock 3.2 or headers(which will require oil lines), everything else is stock 82 SC

[82SC]

I got it...take the 3.0L out...put in a new 964 or 993...

buy a 1970's 2.7L with blown headstuds at a cheap price cuz the engine problems...do the big bore on the old 3.0L put it in the 70's 911

sell the 2.7 for parts to recoup my costs!!!!

haha
with good planning and some dought that is fessible

[Bill Verburg]

When I did the transplant I paid $6500 for a very low milage 93 964 engine(this was in 94) and got $3500 on a private sale of my 110,000 mi carrera 3 liter.

[Bill Verburg]

The best candidate for a transplant is a "belly button car" ie everyones got one nothing special. I financially should never have done that to my car, but it was what I had and what I liked, I like it even more now, others would probably have different opinions.

[82SC]

belly button car???

not quite sure...

so how do you like the car? what are the specifics? any detail?

thanks for the info