Carrera 3.2 Engine - Oversizing to 3.8?

[preston_brown]

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.

[Henry Schmidt]

Latest Supertec magic
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

[KeoRS]

The engine's a beauty!!

Has the 3.2 intake been extrude honed?

[Henry Schmidt]

Originally Posted by KeoRS

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

[KeoRS]

Originally Posted by Henry Schmidt

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

[Henry Schmidt]

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.

[KeoRS]

Originally Posted by Henry Schmidt

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!

[Henry Schmidt]

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.

[KeoRS]

Ohhhhh crap!!! Mucho fun in the sand

[Flieger]

They gonna' do Baja?

[KeoRS]

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

[CaptainCalf]

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

[0396]

count me in...sub

[KeoRS]

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

[AlfonsoR]

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).