Bang For The Buck - Please Help Me Select My New Engine!
 

** Posted this on rebuild forum without any responses - hoping to get some here**

I have an 80 engine that I am rebuilding and it will be dropped in my 82SC: http://forums.pelicanparts.com/porsche-911-technical-forum/399544-another-engine-rebuild-thread-80-3-0l.html

I thought that I had a good plan in place for modest upgrades but now I am having second thoughts.

On page 113 (Wayne's Top Engine Picks) of Wayne's rebuild book I was considering the first option - 95mm JE Pistons with 964 cams and SSI heat exchangers.

Currently my 82 has headers and a Bursch exhaust as installed by the previous owner. So I was going to skip the SSI heat exchangers b/c I don't want to spend another 1k (probably more than that with backdating) on the exhaust system.

At this point I am considering these four options:

1) Use stock Mahle pistons, stock cams, SSIs

2) Use JE Pistons, 964 cams, keep current headers

3) Use stock Mahle pistons, 964 cams, keep current headers

4) Use stock Mahle pistons, stock cams, keep current headers

I am leaning towards #2.

So which set up will give me the most bang for the buck?

Please advise. I am preparing to ship parts out early next week.

Thanks,
Craig

If you are sucking more air in (cams and Pistons), then consider where it has to go and how it will flow...

ssi's are rumored to be worth 20Hp out of the box.

YMMV

If I read the options correctly for 1 & 2, I would say that a 964 cam (or similar profile Webcam 20/21, DC13 by camgrinder) would give you best bang for the buck.

I assume by using JE's, you are trying to save some dough?
Can't comment on wear & longevity of the two types sorry.

Keep the headers until you scare up more money. Easy to add later

Consider having some intake port work. The 80 SC engine can pickup some power in the higher RPM.

The JE's have higher compression ratio over the stock pistons. That is why I thought that they were included in Wayne's pick.

Oh, I love building someone elses car.

If it were me:

Cams, head work, distribuitor recurve, better muffler w factory P&C's.

964 cams or what ever cam Web or Smart Racing recomends. Also, some quality head work on your small port heads.

Factory P&C's. If originals are servicable I would keep em as the 80 SC has the higher of the two in compression.

J&E's for a race car with as much compression as your fuel source would handle.

I would keep the headers and look at the muffler. A good stock two in with a second pipe on the right added.

Look into having the distribuitor worked up by someone in the know or better yet, a protramable single plug ignition.

The JEs are great pistons but you should know that you will be hearing them when the engine is warming up. The Mahles have a much better fit across the temperature range.

If you are going to consider sticking your head this far into your engine why not put larger cylinders on it? Displacement is the number one way to increase output. A nice set of 98mm pistons and cylinders would drop right it.

The JE's on Mahles have different expansion rates - and you will hear them knock as the engine warms.

JE's with nickies from LN engineering have similiar thermal expansion rates. I'd save your pennies and stick with stock or upgrade to higher displacement with mahle or the nickies.

I'd check with camgrinder to so what's the best cam he recommends for CIS (assume are keeping it)

Have you done the math on selling your 3.0 and putting in a 3.2 with SteveW chip, test pipe and M&K muffler?

The 80-83 CR is 9.3:1 while the JE setup would be 9.5:1 ... did I miss something here?

Done the math. I would rather have a rebuilt 3.0 than a 3.2 with miles on it. Nothing against a 3.2. It is just that I could end up having to rebuild it after a year or two ... so it could potentially be much more expensive.

Also, I WANT to rebuild the engine. Yes I would like a little more HP/Torque but I am also doing it b/c I want to understand the 911 engine and want to know that I can work on this car for the rest of my days. Kind of a conquest thing at this point.

I don't hear anything on mine, in fact they are a tad more quiet when cold then the Mahles I swapped out.

Thanks for the details on the JEs. Very helpful.

I think that I am more confused that ever now!

A 3.2L would provide you with EFI a valuable consideration.

My 2 cents:

If you are going from 9.3:1 stock pistons to 9.5:1 JE pistons, I think you are spending a lot for little to no appreciable increase in power. If you went to 9.8:1 you would get a measurable increase, although it might not be huge, it adds to the things you are planning.

SSIs do add power (just did it) Headers should be the same shape as the SSIs, so unless you want heat, keep the headers (and save weight) You are already getting the benefit.

Per Bruce Anderson and Wayne, the 964 cam is a good way to go.

Personally, I'd do #3.

If you went to 9.8:1 pistons then #2. Might be a good $1000 investment. Plus you could sell the 9.3 pistons to offset the cost.

I don't know about bang for the buck, but I really like the way my engine came out. I had it built by Surertec in 2003 and it turned out amazingly quick and reliable...lots of torque and pulls good to redline. I wanted a long-term, bulletproof street engine and am very happy with it. I used the JE 9.5 Pistons with Mahle cyl (no noise at all), but I would consider keepining your 9:3 stock ones if they are in good shape.
WebCams 20:21
Early CIS/large intakes /runners(1978)
Rebuilt top end-new valve guides/valves, 49 in, 41 exhaust, ports 39 in, 38 exhaust
SSIs, early SS muffler
While I was in there I put in a new clutch, rebuilt the distributor, and put in a high-torque starter.

$.02

Stock 9.2/1 pistons if good, head work, & C2 cams.

Set A/F's (and total advance) on the dyno.

I think going from 8.5/1 to 9.5/1 is good for somthing like 5% hp. 9.2/1 to 9.5/1 shoud not be more than 2-4hp.

Small port heads (34mm) were built to increase port velocity at lower rpm to promote better air fuel mixing with CIS for smog. CIS is great but it just keeps spraying fuel that sits in the intake port until the valve opens. This is also why CIS pistons are designed like they are to create a swirl action to get the fuel and air mixed.

The intake ports can benefit by being opened up to 36-38mm to support good hp up top.

Your exhaust side is fine except not sure about the muffler.

The 2.7S had bigger intake ports.

If you have a good machine shop/ builder I think they can deck the heads 1mm for higher compression. Decking the case is better yet. Not sure about this with the C2 cams though.

To much fun.

How about sending the cylinders to EBS to bore to 98mm & re-plate for a 3.2 with J&E's.

Or, add to this a Carrera 3.2 crank and rods for a 3.4 260hp CIS monster motor.

Again, big ports & now 1 7/8" headers...

Done.http://forums.pelicanparts.com/suppo...leys/smash.gif

Wow ... some of you guys are starting to get creative!

For the record ... dropping in a 3.2 is not an option. I have an 82SC that runs great but needs a rebuild. That is why I bought the 80 engine - to rebuild and drop in the 82. The 80 engine is already torn down ... so I am way way way beyond the point of going with a 3.2 EFI.

For those of you making proposed engine packages, please include estimated costs per upgrade item (if you happen to know what it is). The MAX that I want to spend would be the 964 cams ($500?) and JE pistons ($1k) ... I can only consider options that would be less than this.

+1 on #3.
I don't know why mca wants to talk himself into JE 9.5 pistons when he has Mahle 9.3 ??
If he is not restricted with Aircare, I would change the CIS to an early '78-'79 with the larger runners, get rid of the Lambda and increase the ports on the heads.
Later sell the Lambda CIS.
However, if Aircare is an issue, stick with Mahle P/C's (Maybe machine the heads a little to get 9.8 CR?), 964-cam, keep the headers etc......

Then drive and have fun. :)

3.0 liter SC 95mm cylinders cannot be changed to 98mm because of the gasket-groove on top; only 95mm cylinders from 3.2 liter Carrera engine are converted to 98mm by EBS because they don't have the groove.