SC engine upgrade questions...ones with hotrod SC's please respond...
 

Let's start an end all post for SC engine modifications

I have a tired SC and want to rebuild, and extract more power.
I know the whole transplant deal and I have taked to everyone under the sun about that so...no posts about transplants please.

I think there is just something very cool about building your own engine and running it in your car...very cool...and if the $$ are similar and the results are similar I would rather rebuild my own and say it is mine

So out with it folks...here are the things I know fo so far

1. add pistons and cylinders bringing displacement to 3.2, similar compression around 8.5-9.0:1 making a, what is refered to as a short stroke 3.2L

2. add 3.2L carrera crank (what are the details?) again making a 3.2L with similar compression as stock which is refered to as a long stroke 3.2L

3. Do both 1 and 2 to make 3.4L engine.

4. Cams depending on induction system can go with RS cams, 964 cams etc...what are the different personalities and outputs. What works with the CIS, MFI/Webers
Note: I want to build a motor that is ready for MFI...I can live with having no the optimal output when the rebuild is done, but once the emissions laws on my car get lifted it is going to MFI so I want it to be optimized for MFI down the road...so I am envisioning pistons with deep pockets but running milder cams till I get the new induction system

5. Induction system CIS vs MFI vs Webers vs ???
I know the CIS is not made for power...and the MFI are heard to be alot of fun....what are your experiences.

6. Porting and polishing...necessary? what are the advantages?

7. Heads
Some have gone to the 3.2 Carrera for the optimized combustion chamber...and ideas? what about the differences in port sizes between older and newer SC's? Can the new head be made to resemble the older model? What is the advantage here with larger ports?

8. Twin-plugging
necessary for higher compression pistons so that they can run on regular gas. But what about the costs of the distributor etc...is it worth the costs? I know someone mentioned a poormans way with switching guts from a 964...

9. Pistons
With any of the above pistons and cyl modifications what about the ability to go for a high compression ratio...does this nessitate twin plugging? what are the advantages. Also some of the newer pistons have the capacity for hotter cams. any thoughts on this?

10. Exhaust
the concensus seems to be early heat exhchangers/SSI and a dual in muffler. what about early sport muffler and aftermarket? I am running a 2 in 2 out dansk...sounds like a V8...people hate noise...I love it...

11. boring out cylinders
is something I have heard about but don't know much about at all.

12. trying to emulate the road going 3.0RS (RSR)
What is involved here? I think the engine case is similar to the 3.0 carrera engine...no? what parts would be involved

Please post your experiences and what you have done...pic are great, where you got parts, who did the rebuild any resources...also if not too personal ball park cost of mods would give readers a good idea about options

anyone who wants to add catagories let me know and I will edit this one.

This should be good for all those who ask this question and search the archives...I started one a while ago, but did into go into major detail about questions...lets try to keep the posting to the people who either have modified SC engines or the guys like Warren and John Walker with experience to keep the thread uncluttered...

Maybe if some one can write out a "money no object" combination, "track ready" combination, "street going" combination, "budget" combination...then things like torquey, highest hp, best middle of the road, personal favorite combination....etc...

Thanks

MJ

PS can you smell the SCWDP....muahahahahaha

EDIT: Well the post below says this is very open ended and I agree. Let's put some constraints:

money wise and parts wise it should be parts that are readily avalible or can be found with some leg work. No 935's!!! or laser welding additional cyl

And for money...that is hard...but something that maybe if you had a nice windfall or saved up money would could see yourself spending...if you want to spurge a little got ahead...

Emissions: there are guys who live in states without control and those who do...so I will leave this up to the responder...I am waiting for my 1982 chassis to be smog exempt in the next 5-8 years...

I would like to hear proven examples and not theoretical combinations...that was we can hear characteristics of the car in terms of torque, hp, torque range, peaky torque curve, etc...

A related question, what is the most power the stock CIS system can support?
I would like to get higher HP from my car, but at the moment (and for the forseeable future) I am limited by California smog rules. Exhaust is fairly easy to swap out every 2 years, swapping CIS for Webers, not so easy.

Tom

Unfortunately your question is too open ended. The limiting factors are always at least 2 fold; legal restrictions and monetary restrictions. If there are no restrictions then build a 935 replica engine and be done with it. So, can you rephrase and include some more realistic constraints? Which should include, but not be limited to the above? Other considerations may include intended use, reliability requirements etc..

Unless you keep an extra motor for the test man, you can't do much with the SC living in LA. Unless you are planning on an all track car....

SSI and 964 cams with the CIS is about all you can do......then you have to convince the tester that those nice looking heat exchangers are dual cats, crossing yer fingers that the adjustments you made last night will still pass.....

MY SC, barely passes w/o a smog pump....looks like it will go on to be legal when tested for the extra assurance....

I understand your question exactly. My problem is the answer is a moving target.
I believe that you want to have the satisfaction of rebuilding your own engine.
Good for you, nothing wrong with that. The problem is that it will be an ongoing
project with a completion date within the next 5, 7, 10 years. This is based on
CA antique tags and not having to deal with emissions.
For the foreseeable future you will have to live with CIS and cats.
Forgetting the engine size (3.2 vs 3.4) you mention changing cams. Will the new
cam work with CIS?
Port/polish or go with 3.2 heads. This may enable you to move more air but once
again will the CIS handle it?
Pistons and higher CR-anything over 10.25/10.5 and you should go to twin plugs.
The sad thing is the higher the CR the more power. You may be able to find a
twin plug dist, best guess is 1000-1200. The better solution is probably the
Electromotive style twin plug that will handle EFI, but EFI can only be added
after emissions goes away. Back to the moving target.
What is the target for your project? Is it a street motor, killer street motor,
race motor, all out most hp ever produced motor? Again, that ol' moving target.
Then to really confuse the picture you add in "if the $$'s are similar and the
results are similar" we can stop right there.
The $$'s cannot be similar. You've got too many options, 3.2 vs 3.4, stock CR
pistons vs hi comp pistons, stock cam vs hi po cam, stock heads vs port/polish
heads vs 3.2 heads etc, twin or single plug, the options are unlimited.
From experience, every time you change one thing it ends up making you change
something else. I'm not trying to bust your chops but am trying to point out
some of the problems.
It will be interesting to see what kind of answers you get to your questions.
Good luck with your project.
Don Wohlfarth

Here is an email I got (with a first line change...;) ) Don knows what I mean...see edit to 1st post...

Tom,
I've been told by people who know more about this stuff than I do that CIS can support up to 250 HP (that is K-Jetronic from '78 to '80 without the lambda sensor). On my own I've scoured the universe to find out if there was a way to enhance the stock K-Jetronic to improve airflow (and hence increase HP) into the engine. No joy. Cylinder displacement and exhaust backpressure appears to be the limiters to power improvement.

'82SC
I too have read Bruce Anderson's book and a lot of discussions of this board about hot rodding the SC motor (I've got an '82 SC also and had the same questions as you). My personal opinion leads me to believe that building a "high-output" SC motor looks like it will be very expensive relative to the horsepower gained. Per various discussions here on this website by people who are actually doing these things, seems like the guys who are dropping a 3.6 L engine into their cars are much better off when looking at $$/hp and emissions issues. However, I think, given the light weight of the SC, you would be happy with the way your car would feel with a 30 HP gain.

82SC...you don't have enough tickets yet? http://www.pelicanparts.com/support/smileys/wat.gif

THis is also well discussed on the SC RS and "help choosing a camshaft thread". Actually well discussed means I wrote a whole lot of probably incorrect stuff, but others had useful things to say :)

Both threads started by "cds72911".

Cam

"Both threads started by "cds72911".

Cam" Cam? Hmmmmmmmm Thanks!

For all the money your laundry list of heads, pistons, cams, etc would cost, there is no contest...You must SUPERCHARGE!

A nice Paxton setup as has been discussed here before is the best bang for the buck.

Nothing to post, except I take Bill Verburg's words seriously.http://www.pelicanparts.com/support/smileys/dom.gif

I am going to be rebuilding my engine very shortly. Right now it is a 79' 3.0. I plan on twin plugging, P/C's to 3.2 with 10.5 compresion, Webber carbs, upgrade all head studs, and headers with 2 in 2 out sport muffler. I am hoping to get 300hp a the crank with this setup. Am I to optimistic.


MikeZ is the 25 year antique car exemption still in affect, and will I qualify in two years for that?



Thanks.

Iris belongs to Randy Jones, (AKA RLJ) and her 281 HP "measurements" can be found here: http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=4483

As to the 25 year exemption for CA smog, there isn't. As I understand it, the law says 1973 or earlier, with a rolling 30 year exemption. Unless the law changes you won't be exempt from smog checks until 2009. It could be worse, I won't be exempt until 2012.

Tom

30 year smog.....25 year for antique/vintage....different animal.

Really? What qualifies as "antique/vintage"?

DITTO, I'll say my car is vintage. How can I do this? 3 more years !?!?!?!?!

The reg says....25 years old and of historical interest...no definition of historical interest...so, whatever you can convince the drone at DMV it is.....I had some BYatch, tell me my 914/6 was not of historical interest...

I asked her to tell me what was....she gave me her best blank state employee stare.....I stared back....I'm better, I told her that unless she showed me a defenition in writng, MY car is of historical interest...because I SAID SO.

She took my money and said, well Sacramento decides anyways....stupid twit. Either way, I've seen them on other 914/6s so there is no problem....kind of a bad secret.

25 bucks for the plate and 2 bucks a year, no smog test and you are limited to driving to club events....kind of like going to AA meeting with a suspended license....there's allways one around someplace...:eek:

I, too, would like to get more power from my '82 SC. I plan on resealing it this winter,(rings, valves, etc.), 964 cams and SSI's+ lighten it some,(RUF fg bumpers).

The problem with doing more than that is that it is an absolute "law of no return" dilemna. My car is a pretty nice one, never smashed coupe w/ 110k miles, and I am also sinking $ into stereo, suspension,etc. At some point I could just buy a better, (and faster), 911. If I stick to plan, I should be able to get most if not all investment back if I sell to upgrade. Why do you want to keep that particular car forever? I like my car, but SC's are not that special, (insert flames here).

Sounds like you have Porsche OCD even worse than me, but that's what we Pelicanheads are all about. :)

Didn't we go through this all before?

http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=4620

250 hp - 300 hp Sounds like fun. At what point does "dowel pinning" and serious crank mods become coffee conversation in the SC??

A few answers, more questions
 

We have 2 dyno examples of cam changes on CIS 3.0 engines, from Noah and Mikez.

Both engines have higher compression pistons (Noah, 9.5:1, Mike 9.8:1 assuming stock ROW compression) with 964 cams and early exhaust. Noahs was 203HP at the wheels, Mike's is 224hp at the crank. I looked at the charts in Bruce Anderson's book, and the only mechanical difference I see in these 2 engines is the size of the intake ports, 39mm for Noah, and 34mm for mike. Valve sizes and exhaust ports are the same size. I know the fuel system is different, because I remember Noah searching for a fuel distributor.

So how different is the CIS system on a 77 Carrera 3.0 (Noah's car, may it Rest in peace), a 81+ ROW SC (Mikez's 914/6) and a stock US 3.0? Is there anything to be gained from changing the fuel distributor? What is the difference between the 78-79 and 80-83 fuel distributors?

Tom

JE Hi-compression pistons, balance all rotating parts within like 2/10ths of a gram, a good street grind on the cams, 40mm IDA Webers a set of SSI exchangers and dual in/dual out muffler.

What more could you ask for?? ") Well, that's what I dream of anyway.

Bill V.
Great thread lots of good info!

Steve W.
What size wristpin are you using with your 100mm pistons? What other mods did you have to do?

Anyone in Calif.
How do you get away with the wild mods being posted?

Bit of clarification.....my 224 hp dyno results at the crank was on my 3.0 in my current euro spec 911. It DOES NOT have the 964 cams, only SSI and dual inlet/out muffler and no smog pump......this engine only has 60K on it and I don't plan on pulling the motor until I have too.....

My 914/6 3.0, had the 964 cam upgrade. I did not do a dyno on that car and have since sold it....it also had a euro spec 3.0 with CIS....headers, bumped up compression etc.....

http://www.members.aol.com/rattlsnak/ignfuel1.jpeg

3.0 SC, 964 cams, B&B headers, electromotive fuel and crankfire ignition = @250 HP

Mike, Thanks for clearing that up. When you posted the 224 number on another thread, I dug through the archives to see if I could figure out what you did. Looks like I got your cars confused. My bad.

Still, 20HP from an exhaust change is pretty good, especially when your engine has the smaller intake ports (like mine).

Noah, the fact that you had a 2.7 fuel distro on your car tells us something about the capabilities of the fuel system. I don't have the book in front of me, but the most power from a 2.7 CIS car was what, 170HP at the crank? That you were able to get an extra ~60HP (conservatively, maybe as much as 70) more than the system was designed for, makes me think the 3.0 CIS system should be capable of providing the fuel needs of a 250HP engine without any difficulty.

This raises another question, is the later 80-83 CIS system with Lamda as flexable as the earlier systems?

Tom

Tom,
The idle mixture can be adjusted on the lambda system just like previous systems but the lambda computer will always lean the output of the fuel distributor back to 14.7/1 air/fuel ratio for low emmisions. I believe that John Walker suggested adjusting idle mixture to 3% O and leaving the O2 sensor disconnected for improved performance. However there are some who say this will degrade performance. I'm going to try this next spring.

82SC writes:<br><i>
5. Induction system CIS vs MFI vs Webers vs ???
I know the CIS is not made for power...and the MFI are heard to be alot of fun....what are your experiences.<br></i>
Have you considered an EFI system? There was an excellent thread on this subject a few months ago...<br>
http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=10077<br>
A good source of info and advice would be NATCHAMP, his car, the BEAST, can be viewed at his website http://www.mark.hargett.com/

It is a gorgeous car with a pretty slick EFI system installed...the prize, however, must go to stlrj for his 3 litre flat six/Chevy V6 EFI hybrid. Here is what he said in the CIS to EFI Conversion thread...<br>
<i>stlrj
Senior Member

Registered: Dec 1999
Location: Novato
Posts: 421

I did a CIS to EFI conversion on a 78 3.0 a while back and used components off an 85 Chevy 2.8 V6.

What I ended up with was a very responsive, powerful and fuel efficient 3.0 that included all the "on board diagnostics", hot film mass air flow sensor, head temp sensor, throttle position sensor, computer controlled HEI ignition, Bosch injectors, complete wire harness, etc. all for less than $150 from the local boneyard.

I'll post some pictures of my modified intake manifold and air box later.

Fun winter project

Joe Garcia
86 Carrera
Redwood PCA since 1976<br></i>

I understand Ben Willis is in the process of doing a DIY EFI conversion to his SC. No doubt he knows a lot as well.

Good Luck !!<br>

Seemed like a good thread to attach an outline of my power upgrade project.

Swap a 3.2 litre into my 78SC. Motor will have PMO carbs, single plug-electromotive, 10:3 or 10:5 comp JE pistons,elgin cams, new valves, rods, springs etc.. headers and a sport muffler. Hopefully good for 280-290HP. Should be ready for next seasons DE events!!:D

Everyone seems to be dancing around the the question of what to do and still keep the car so it is streetable and emissions legal.
My suggestion would be to find a tired 3.2 that needs rebuilding and sell the 3.0.
Cost of rebuilding 3.2 would be similar to 3.0 so that's somewhat of a wash. Install the 98mm p&c's and put it back together.
You'd end up with a 3.4 with Motronic and the motor would have Carrera tensioners. Cam choice would be a wash between 3.0 vs 3.2.
Main cost difference would be between cost of 3.2 and selling price of 3.0.
Motor would still be close to "stock" for emission issues, you've gained 24.4 cubic inches, and you've improved the fi from CIS to Motronic, and best of all you've accomplished your objective of rebuilding your own motor.
Yes, you can cobble something together with 12:1 pistons and racing cams and spend the next 5, 7, 10 years with it parked because you can't pass emissions.

I have just recently became a Proud Pappa of a 80 SC Targa in need of a rebuild and am new to this wonderful outlet/resource of info. I had every intention of using 9.8:1 pistons and 964 Cams, but have noticed that some are suggesting using 3.2 P&C. Will this work with the CIS and are there any other mods that I might have to make in order for them to work? Also will the 964 cams still help out on the ponies on the higher end of the RPMS?

Any info would greatly be appreciated and I have started reading Bruce and Waynes books on rebuilding for this project.

If emissions stay, 3.2 P&C's with 64 cams, open exhaust (same as you have). That should give it some all around good kick.

No emisions, 3.2 P&C's, head work or 3.2 heads, S or better cams, some twm stacks, tech 3, twin plug.

No emissions or money limit, over bore 3.4 with the short stroke, twin turbo's like some garrett gt turbos, custom intercooler with a 3.2 intake, and whatever else i can't afford.

If emissions stay, 3.2 P&C's with 64 cams, open exhaust (same as you have). That should give it some all around good kick.

No emisions, 3.2 P&C's, head work or 3.2 heads, S or better cams, some twm stacks, tech 3, twin plug.

No emissions or money limit, over bore 3.4 with the short stroke, twin turbo's like some garrett gt turbos, custom intercooler with a 3.2 intake, and whatever else i can't afford.

A lot of these hp figures seem optimistic for a street engine.

I agree you will be $$ ahead if you just get a 3.2L to start with. Then you don't have to get the heads, you'll already have them. Putting a 3.2 crank into a 3L is a lot of work and $$.

As Bill V. said figure out what you want first, then repost.

You may want to just put in a stock 3.2L now and modify it as the you hit the smog relaxation time period.

BTW, I'd bet money that twin-plugging will reduce emissions.