Carrera 3.2 Engine - Oversizing to 3.8?
 

Good day to all;

I was reading my copy of the Porsche 911 Performance Handbook. On page 170, there is a list of piston and cylinder sets for different 911s, including oversized combinations.

It lists a 3.0/3.2 oversize to 3.8L piston/cylinder set (100 x 76.4). I've read quite a few on 3.4 conversions. There is less information on 3.5 conversions... and I've yet to see someone who has done a 3.2 to 3.8 conversion.

Has anyone ever seen/done this. Are these piston/cylinder sets still in production? I can't seem to find sets specifically to oversize a 3.2. I was able to find 100x76.4 3.8L sets made by Mahle and JE Pistons, but they advertise them as 964 oversize kits. Are these compatible with a 3.2 core and would any additional modifications be needed?

Here is the link to JE Pistons website, look towards the bottom:
http://www.jepistons.com/Catalogs/Automotive/Porsche.aspx
3.8 102mm 76.400 Compression of 11.5 (Kinda high for North American gasoline, no?)

Here is the link to the Mahle set sold here on Pelican Parts:
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=PS102-015-M362&catalog_description=Motorsport%20Piston%20%26 %20Cylinder%20Set%20%2D%20%33%2E%38L%20RSR%20%28%3 1%30%32mm%20bore%2C%20%31%30%37mm%20Sleeve%2C%20%3 1%31%2E%35%3A%31%20Comp%2C%20Slip%20In%29%2C%20%31 %20set%20per%20car%2C%20RSR%20rods%20required%2C%2 0%39%31%31%20Carrera%2F%34%20%28%31%39%39%35%2D%39 %38%29%20


On a side note, I hope all fellow northern pelicans are taking the opportunity to ride in their p-cars on every sunny day before snow starts to fall and it's yet again time to store our beloved cars.

Thanks in advance for any feedback on this type of conversion!
Kev

Of course it can be done.

http://img.photobucket.com/albums/v1...d/DSC02475.jpg

http://img.photobucket.com/albums/v1...checksmall.jpg

Specs are:

Based on a 3.2 case – boat tailed
3.2 74.4mm crank stroked to 76.4mm Re-nitrate
Using 2” rod journals utilizing NASCAR type rod bearings.
Center drill for better oiling to #2 and #5 rods (special center main bearing) engine will be able to turn to 8600 rpms, but we are holding it down to under 8000 rpms.

Custom Pauter Connecting Rods – using Raceware Hardware
Camgrinder -DC62 profile on a 108° lobe center
Race Springs, Ti Retainers

3.2 Heads – Dual Plugged & Ported

102mm LN Nickies 11.3 to 1 CR

JE Pistons coated

52mm ITB’s big injectors – FP Regulator (plus all kinds of other stuff)

Smart Racing Oil Filter Console

1¾” Nabel’s Headers into an (M&K Sport Muffler for street) M&K Shorties on the track

Spark and Fuel controlled by Haltech E-8 Engine Management System
Crank Fired Wasted Spark Accel Coil Packs

Light weight Al flywheel and HD clutch

NY65912, very nice just doesn't say it well enough, that has to be one hell of a ride with that engine in it.:eek:

The link that you gave for the Mahle's are for a 964 3.6 engine to be upgraded. Looks like the Nickies will take you to a 3.7 with machine in cylinders. Enjoy a great project. Check with Camgrinder Dougherty Racing Cams for recommendations on the right cam for what you want from the engine. Wish I had the budget to take it to 3.7 as I am very happy with the outcome of my 3.4 rebuild.:cool:

Man, that is sweet looking. What kind of HP you crankin?

Cheers,
Emerald

Thanks guys, The real genius behind the 3.8 is Bill Rudtner. We collaberated and he made ithappen.

The engine did 365 to the rear wheels, with a 15% drivetrain loss I believe we were looking at 415 crank.

I had Bill make a less aggressive street map to be more user friendly on the street.

Due to health issues it has become more difficult to attend track events, but I hope to get back soon and use the more aggressive track mapping.

Oh yeah, it pulls like a freight train to 8600 rpm.;)

That's insane!

Thanks for posting this. It's really impressive. I'm sure it sounds amazing. This kind of setup is rare and I feel it has a bigger "raw" factor than a forced induction setup.

415hp NA... NICE!

Mike, what transmission is hooked up to your 3.8? G50? Did you change any gear ratios or are you running a stock transmission with an upgraded flywheel/clutch?

Keo,

Currently I'm still running a stock 915 and have virtually no miles on this engine. I'm running a light flywheel and HD Sport clutch.

Plans do include a G50, and more suspension work IF I keep it.

Right now we are undergoing an IROC upgrade.

The big problem is my health.

Over the last year I have had a few problems and progress has been slow.

i was pondering selling the 3.8 and refitting a stock 3.6 in it's place for better street drivability as my track time is up in the air.

Hey Mike;

Sorry to hear about your health. It's awesome to see you on the boards! I hope the members are able to keep you on a positive mindset!

I really like the choice of engine mods you've done with your track project.

I'm sending you positive waves SmileWavy so that you get better soon and maybe you won't sell your track project after all!

Man.... what an engine....3.8 droooool

Mike, What is the exhaust setup like on your 3.8??

Headers are George Nabel's European Racing Headers in 1 3/4" with an M&K Sport Muffler

http://img.photobucket.com/albums/v1.../untitled1.jpg

http://img.photobucket.com/albums/v1...d/DSC01862.jpg

Nice setup.
But headers in the second picture might have been put on the wrong sides.

Thanks Mike... I have a similar setup to yours. Keo, it might be an interesting reference for you, so I'll post some details. Your engine won't be quite like mine, because I have a lot of 964 & 993 parts, but it is important to understand "slippery slope victim" directly below NY's username

I'm running a 964 case with a worked crankshaft, and custom Pauter rods (longer) and JE 12:1 pistons. Stock 964 cylinders (only 3.6L displacement :( hahahah), 993 cam boxes modified for solid rockers. 993 3.8 RSR cams and port sizes, Vellios injection with autronic engine management. I am not running a super light flywheel and clutch combo. The sticking point has been trying to figure out an exhaust that won't choke off all the power, but isn't horrendous to live with. Right now I have a B&B system that is 2 in 2 out, and the droaning is unbelieveable, and unbearable. I have tried a flowmaster muffler, but all my throttle response went out the window. I have then next option picked out, but I'm getting sick of trial and error. At this point, I would settle for something that sounded good, even if I had to give up 15hp. Slippery slope almost seems like an understatement these days!

In all reality I'm probably running too much cam for the street. I can't seem to get enough flow through a muffler to take advantage of the high RPM horsepower. I really should go back to an 11:1 piston, and a more reasonable cam, but it's not in the budget for the moment.
http://forums.pelicanparts.com/uploa...1256908826.jpg

smokintr6;

your setup looks brutal!

Does oversizing from 3.2 to 3.8 affect the responsiveness or driveability in any way that it might be better to opt for say a 3.5 or 3.6 oversize?

I think the responsiveness on the street would be to use a more moderatley sized ITB.

I'm running 52mm. I am thinking of dowsizing to 50mm or thereabouts. I have yet to discuss this with the builder.

Since my direction will now be more street than track, I think a smaller ITB would be called for.

Drivability on the street, (as is) is like driving a bucking bronco.

BUT, when she catches.... hold on!

Mike, I wish I knew what size my ITB's are, because I don't have any trouble in town. my car runs like a kitten up to 4,000 RPM, and then Screams like a banshee until 7,500. Under 4k I don't make much more power than a nice 3.2, but above 4500, it's a different ball game. Quick WOT at 1500-2000 makes it a little mad, but I don't have a reason to do it. I had no trouble with standing starts for autocross. I'm sure you'll get it figured out.

Keo, have you considered buying a complete 3.6 engine to swap in, and sell off your 3.2? That is probably actually your most cost effective solution. You are rolling the dice on a used engine, but with due diligence you can ovoid most snares

I have given it some thought, but I rather like the idea of knowing the engine inside out and being able to trust it's reliability for the years that follow the build. Also, from what I've been reading the 3.2 is a great platform to augment performance. Of course, it doesn't come without expenses.

However the whole process of deciding what exactly I'd like to build out of my engine is more than motivating. As they say... the journey is just as fun as the destination. ( if not moreso... how many people build crazy cars and then sell it off for the next "project" - which I don't plan on doing! My p-car is a keeper!)

So back to the technical stuff, guys. If I understand correctly, the minimum needed for the 3.8 oversize is:

-102mm X 76.4mm P+C set with 23 mm wrist pins (custom ordered I suppose?)
-Crank stroked to 76.4mm ?
-Dual plugs

Any thing else in the "required" category? Can the motronic handle the changes or would I absolutely need an aftermarket engine management system?

I understand that there are additional modifications to bring in order to obtain peak performance, but I'm just trying to understand what's required and what's ideal.

Any input would be awesome!
Thanks in advance, guys.

Kev

102 mm LN Nickies Cylinders
3.2 Crank - Stroked to 76.4mm

Can't comment on Motronic as I am running Haltech.

Cam selection is critical.

Thanks for the quick reply, Mike!

Any updates on the 3.8 project?

Speaking of the Haltech eng. mngmnt system. Does that use the stock wiring harness or does that need to be updated as well? Are you satisfied with it as of yet?

Also, I completely understand that the cam selection is critical. If kept stock, I suppose it could run but it wouldn't be no where near ideal.

3.8 is soooo tempting. I'll research even more on it now!

Kev

How about a titanium rod tytanium valve 4.0 liter?
http://forums.pelicanparts.com/uploa...1266542301.jpg
http://forums.pelicanparts.com/uploa...1266542473.jpg
http://forums.pelicanparts.com/uploa...1266542523.jpg
http://forums.pelicanparts.com/uploa...1266542552.jpg

Henry;

Droooooool. 4.0L :cool:

Looks like a killer engine. Is that based on a 993 engine? Seems like the shroud came from a 993. If it's a 3.2 case, I'm impressed. Quite the oversize... and I thought 3.8 was pushing it ;)

Wow, that looks really cool Henry. How will that little cooling fin area work to cool that much motor? Not doubting it, but it looks like tons less than the amount of surface area available on a 3.2 cylinder.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/432350-latest-supertec-magic.html
Sorry 3.6 964 base engine.
964 heads with Del West ty valves Burillium seats
Supertec Venti-Port 40 mm
964 case
Nickie 105
GT3 crank.
GT3 oil pump
GT3 rods
3.2 Carrera intake
http://forums.pelicanparts.com/uploa...1266551359.jpg
http://forums.pelicanparts.com/uploa...1266551447.jpg

The engine's a beauty!!

Has the 3.2 intake been extrude honed?

Thank you.
We don't extrude hone 3.2 intake because the people who pioneered that process (Andial) reported no significant (measurable) improvement in performance

Henry;

Interesting. What factors influenced you to use the 3.2 intake vice the 964 or 993 (plastic)? I was under the impression that the 3.2 manifold didn't have an even flow between cylinders as it could have. That led me to think that extrude honing might not bring tangible performance, but offered even flow to the cylinders which contributes to a better balance.

If this is a negligable mod, then the hell with it. That would mean more money in my pockets (as I intended to make this mod once I got in that slippery slope).

I must say though that the 3.2 intake manifold is a beauty on that engine.

Kev

The 3.2 Carrera intake was chosen for it's compatibility with the chassis.
This engine was a special project replacement engine for a sand rail.
All of the ancillary equipment (air filter, power steering pump, Fuel management system) were designed to function with the 3.2 Carrera intake.
High rpm performance in a sand rail is useless so our goal was to build an engine that would make power from 2600 to 5800, with functional power up to 7000 rpm.
The small port heads, custom DC cam profile and shear size allowed us to build a sand rail engine to compete with the Northstar and LS1 V8s.
If higher RPMs were required we would have installed a more flow friendly intake.
Every project has it's own criteria and developing that criteria devoid of preconceived notions is the challenge faced by all engine builders. This forum is a prime example of the struggles engine builders encounter in the quest for the "perfect" formula.

Thank you very much for the insight. Would love to see the car when it's ready!!

I really appreciate having knowledgable people on this board, like yourself Henry, share their expertise.

I read alot and focus my attention on what is said on here in hopes of one day being more autonomous in working with 911s and perhaps contribute back to the pelicans or local pcar owners.

On with the discussion, 3.8 builds galore please!

The engine has been in the car for the entirety of last season. The desert guys are getting ready for their assault and this engine/chassis are ready to go.
This is a 5 year old picture of the chassis with a cabureted 3.7 liter engine. The 3.7 engine lost it's life during an inverted episode. These engines hate running upside-down.
http://forums.pelicanparts.com/uploa...1266588438.jpg

Ohhhhh crap!!! Mucho fun in the sand :cool:

They gonna' do Baja?

Hi all;

Thanks again for all the commenting and sharing of information.

Coming back to this topic. I've continued reading about oversizing our engines and it is my understanding that there are two types of cylinders: slip-in and machine-in.

In my quest to completely understand what it takes to oversize a Carrera 3.2 engine to a 3.8, I felt the need to ask additional questions:

-Is it even safe to use a "slip-in" cylinder for such a big oversize? (I basicly use the pcar for commuting at the moment, but this is slighty due to the fact that I don't feel the car is ready for the odd track day.) I would rather have a bullet proof engine than one that does the job, but just if you stay on the street. Which leads to my next question.

-What machining is needed to enable the use of these "machine-in" cylinders on the 3.2 case? I also read something about "boat tailing" the case. What does this mean? I've also read about having to modify the crank? Any renowned machine shops you guys would recommend?

-Is twin plugging a must at this point? If my 3.2 heads are deemed in great shape, do I simply send them in to a machine shop to have the extra plug insert machined in? Are there any other "while your in there" things I should plan on having done to them? Would titanium springs be a must?

-I noticed that Web Cams sell 3.8 RSR cams. However, alot of people running oversized 3.2 engines seem to have either regrinded their cams to 964 specs or use Web 20/21 cams. Any opinions on this?

-Flame ringing. Seems like alot of the high horsepower engines are "flame ringed". Would this be a smart upgrade? What about C2 turbo gaskets?

and finaly (for now!)

-Motronic... keep or switch to a different EMS? Is it worth changing?

Again, I'm very thankful for any help you guys may provide.
Kevin

This looks like a very interesting project KeoRS, I'm in:)

count me in...sub

Just following up with my research:

These would be suitable P/C I believe:

Part number 103-102.2 - p911 3.2 102mm 10.5:1 JE Piston set inc. rings, pins, & clips

and

Part number 104-102/109 p911 3.8 102mm machine-in 109mm case register - Nickies (LN Engineering) (roughly 4000$ for both of the above)

In order to fit these on my block, I'd need my case's spigots machined to 109mm. Correct? How much would it cost to get this service done?

Also, because the CR would be of 10.5:1, twin plug is a must. It is my understanding that the Carrera 3.2 heads have big enough valves to provide sufficient flow for over 300hp. So if deemed in good shape, I would have to get mine drilled and threaded for the extra plugs. Then have them flowed as a "while you're in there" mod. How much would it cost to get this service done?

Additionaly, these new plugs need to get some spark. So I have found two possible sollutions:

-Patrick Motorsports Twin Plug Ignition System (Priced at roughly 2000$)
or
-The distributor from a 964 or 993, the Andial signal splitter, a second ignition coil and the lower spark plug wires (I don't know the price of this combo)

Now the P/C combo mentionned above won't take me to 3.8 without having the crank stroked to 76.4mm. Anyone know the cost of having this done plus a renitrate? Also, what about cross drilling at 2 and 5 for better oil circulation? Who provides this type of mod and at what cost?

That's it for tonight. I'll be adding more info/questions soon.
Thanks in advance everyone!
Kev

Keo,

What is your goal with the engine upgrade? DO you have a specific HP or Torque figure in mind?

I have been pondering a similar type question: "what's the most reliable and cheapest way to get to 350 HP at the crank?"

I would start with start with a spare engine, if possible, although, that's a $5000 initial cost. The two main paths I see are:

1. upgrading a 3.2 to 3.4 or 3.5
2. upgrading a 993 or 964 3.6 to ??? maybe you can stay at 3.6 and just upgrade pistons and cams

I just got my car and have a couple of other projects I want to do before I get to the engine, but maybe this gives you a different angle to get what you're looking for. Hope that helps.

PS: I think it's better to go with a proven engine combination, that way you can look at what combination of parts people have run, how much power they make, and how reliable it is. Following a path rarely taken (3.2 to 3.8), might mean a lot of stumbling. Just be cautious, is all. Make sure you look at the entire system....you want to make sure your 3.8 or whatever you go with will be able to breath in (admission) and out (exhaust).