Engine advice needed
 

I need some advice on what engine I should build. It would be used in a lightweight RS or RSR replica, about 90% street, 10% track. Requirements lean much more toward street.

My budget is $15k for the engine, and I am starting with a bone stock 1986 3.2 with 115,000 original miles. Never been opened up, but aside from valve guides and rings, let's assume all the usual items are in spec and reusable/regrindable.

I will do all the disassembly/reassembly myself, but I have never done an engine rebuild of any kind before. I've got Wayne's book and I'm confident I have the necessary skills and patience to do it properly by following the book. If you think I'm not being realistic, please tell me so. All the machine work, including head work and any mods, would be hired out.

Ideally, I'd like to end up with a 2.8 of some flavor and configuration, given my budget constraints. I'd like the engine to last at least 75k before needing another rebuild. And, it must be able to pass a fairly strict emissions test, with cat required (but swappable with a bypass for track days).

If the 3.2 isn't the best place to start for an engine like this, I will gladly sell mine and buy whatever case/crank/rods/etc. are necessary. I realize that this kind of work might not be advised for a neophyte.

So, given what I have to start with, the intended use, and my $15k budget, what's your opinion on what I should build?

Follow up question (quick answer): How far outside my budget is a twin-plug MFI 2.8 with ITBs?

Disclaimer: I am not an expert, nor do I have shop experience. I am just an enthusiastic student of the big guns.

The 3.2 crankshaft is 74.4mm stroke. 2.8 RSR was 70.4mm stroke.

3.2 case is Aluminum (good for strength, of course) but the head stud-spacing is wider than the 2.8 RSR, I believe.

Your 3.2 rods are weaker (narrower) than earlier rods.

I would look for a 2.7 with reinforced 7R case or 3.0 liter to be more correct.

If you get an early motor like a 2.0 with MFI you can use JE pistons and LN Engineering cylinders in 90mm bore for a 66mm stroke x 90mm stroke high RPM screamer. 2.5 short-stroke MFI - like in the 911ST. You can make more than enough power out of that. Much more than a 2.7 RS spec (210 hp, 188 lb-ft.)

If you find a 2.2 or 2.4 motor that is tired, you can use the MFI and case and build a 2.7 RS spec+ with RSR power. Use higher compression (10.5 vs 8.5 :1) and twin plug (if the Supertech distributor is in your budget)

MFI can be expensive to recondition the injection pump but the performance is thrilling. Any pump can be tuned to work on your displacement.

I think you should sell the motor you have now unless you want to buy a crank and more.

Good advice but I prefer the 3.2L, it's a good start to squeeze a lot of power. Do it yourself, I too did my 1st rebuilt on this engine.

Good luck, everyone here will help out.

Alex

I figured I would probably have to start with a 3.0 turbo or Euro 2.7 case. Keeping the stock 3.2 w/Motronic is an option I'm willing to consider, as it would be the easiest to do and save big $$. Not my first choice, however.

The 2.2/2.4 cases are magnesium aren't they? Are they strong enough to support an RS/RSR-spec build? For some reason I'm thinking the 2.8 RSR case was aluminum. I'll have to consult Bruce's performance handbook again...

Since the RSR or 917 distributor is crazy expensive, I was thinking along the lines of TEC-3 with coil packs instead. Problem is, I don't know the first thing about tuning an engine so I'd have to have someone local do that for me. I'll research the Supertech distributor to see if that's an option.

Here's what I suggest. Sell the 3.2 and buy a 3.0 SC. It has all of the character of a 2.8, is built on the same crank, has the same strong case as the 3.2 and doesn't suffer the same rod problems. We'll call the motor swap a wash, so add $15K:

If you want a true 2.8, buy Nickies and JEs from LN Engineering; they can make smaller P/Cs to fit the 3 liter case; if not, got 98mm and get a 3,2SS - lots of choices. Twin plug CR. Cost = ~$2600
Send your heads to Steve Weiner for porting and rebuild. Cost = ~$2000
Rebuild your rods and buy ARP bolts. Cost = ~$500
Dougherty cams - ask for the "Jeff Higgins" grind. Cost = $750
Used Electromotive Fuel and Spark crankfire system. Cost = $1500
ITBs = ~$1500

All of this gets you close to 9 grand, with plenty left over for ancillary bits like bearings, fasteners, seals, fluids, plug wires, etc.

Should come in at around $15K and results in one of the most satisfying motors I have ever driven.

You could find RSR motors on both mag and ally cases. Mag was much more common.

If you want the look, a Mike Bruns dizzy is only $1500. Used Electromotive is pretty cheap, too. Lots of options here. MegaSquirt works well, too.

Suppose I built up my existing 3.2 with high compression JE pistons, S cams, ITB's, twin plugs, and ditched the Motronic for used Electromotive setup?

This ought to be good for at least 260 hp, wouldn't it? Depending on exhaust, of course.

It would also keep the engine number matched to the chassis, which might be desirable at some point down the line.

The 3.2 Euro with high compression pistons is already at this level or close to it.
Alex

It's got the high compression, but not twin plugs, S cams, ITBs and advanced engine management.

3.2 Euro was spec'd at 231 hp vs. 217 for the U.S. 231 is nowhere near enough power for what I'm looking for. I would have to mod the thing much further than just building a stock Euro 3.2.

Anyone else got any ideas?

You can spend your budget nicely by doing roughly the following:

Read Trog's thread : "My PMO ITB Project"
http://forums.pelicanparts.com/porsche-911-technical-forum/427451-my-pmo-itb-project.html

then one-up that by going to a ...

3.4 High-Compression 10.3:1 ITB motor with 993 exhaust

Recipe:

-Start w/ a 3.2 Base, add ARP rod bolts and 98mm pistons and cylinders, hot cams, twin plug the heads, and change to ITBs, add 993 heat exchangers (could even plumb a cat in there)

Result should be 300 or more hp, excellent reliability, perfect throttle response. It will be good to keep it under 7k rpm's.

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/FT-f9ov5ypQ&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/FT-f9ov5ypQ&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>