I changed my plans with the heads and sent them off to Bill at Extreme Cylinder Heads in Florida for some CNC porting and flow matching. RSR Getty shroud, straight cut I/S gears, GT3 muffler, and some other trick bits.

Lot of parts showing up daily in mail :) Enjoy some photos. I get my case and crank back from EMS in two weeks.


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I shipped my cylinders to Tony. All six read out at 4-5 Ra. Will be installing these without hesitation.

Nice headers. Did you happen to weigh them, and the muffler set up? And enjoying this thread too, thanks for posting the details and process. Did I miss it, but why not a Scart muffler as in post #1 (at one point I was considering as well but went M&K). Scart seems rare (?) and sound fantastic on Youtube in some clips.

I used to work for a shop in SoCal thats a Scart dealer. I got to hear every possible set up of their mufflers (1 in and 2 in) and test/cat pipe combos together. Hands down the best sounding muffler on an aircooled 911. I have no idea what which craft is going on in there but they sound incredible and that was my main reason for getting one.

However, I'm chasing 300hp for this build and after much research and talking with a few builders the GT3 muffler is proven to show the least amount of HP loss when running a muffler. I got it for a steal on Ebay BIN right after it was posted with tips and hardware included.

Haven't weighed the muffler but I'll let you know this weekend.

I do have a nice set of SSI's on the car now, but won't be selling for a while, I want to get the carb's off and the 3.2L injection on and running before I add a boost variable to deal with.

Thanks, cool you got a chance to hear the exhaust combos in person. More power is hard to argue against though.

Are these the cylinders you had EBS/Millenium do? Good to hear they read out that low if so.
Bill

Building a Short Stroke............
 

I agree with everything you are doing, except............... for using the 12 plug distributor. When I built the 3.3SS for my SC I used an Electromotive XDi twin plug, crank fire system with infinitely adjustable timing controls. There are a couple or three big advantages of doing so. Advantage #1, gets rid of the distributor all together! This makes some space at the left rear of the engine and (big plus) eliminates having to buy expensive distributor caps and rotors in the future. Advantage #2, allows you to "play" with the timing until you find the sweet spot. Advantage #3, gives a hotter, more accurate spark timing. I built my engine in 2013 and have done very little to it since then. The only exception being some very minor tuning when the weather changes from warm to cold, etc. The other specs on my 3.3SS are as follows: 11.0:1 Mahle 100mm pistons with the low dome, KN Engineering cylinders, Porsche 964 cams, big port Carrera twin plug cylinder heads, early (78-79) large port CIS airbox. CIS modified back to 1973 1/2 layout. Basically, I kept the 3.0 block, crank, oil pump assy and flywheel. Everything else got replaced. Never had any oil burning issues, the rings seated almost immediately! Also, after 7 years it has never had even one small oil leak! Good luck with your engine build, hope it goes well for you!

Fred your engine sounds pretty amazing.

I spoke with a handful of well known builders and all of them recommended a 12 plug dizzy over the XDi set up. Based on their vast experience and knowledge, I went with their recommendation.

I will disagree with your advantage #1 because I personally love the period correct look of a huge 12 plug dizzy in the engine bay. JBR caps and rotors aren’t too expensive. The XDI coils do not look pretty in the engine bay and same with the crank fired system.

That’s a lot of work to keep with CIS. Why not ditch it?

Why keep the CIS? Mainly because I wanted to see what could be done with it. It turns out that with a tweak here and a change there it can be made to work well up to at least 7500 rpms! In fact, I had to set the ignition interrupt at 7500 to keep from over revving the engine! One thing I did that I haven't mentioned was to add a spring loaded switch to the throttle linkage that energizes the cold start valve when at wide open throttle. This adds enough extra fuel to change the air/fuel mixture from about 14.5 to about 13.0 to help prevent burning a valve due to lean running. Since it only activates at WOT, the overall fuel mileage is not affected much. As to the coils not looking "pretty" I mounted them on the little shelf between the shock absorber tops where they are almost invisible. Also, I mounted the control box on the little firewall below the right rear seat where I can reach back and tweak the timing if I want/need to do so. This is your engine in your car so by all means, build it the way you want!!

Build is awesome! Great job!

I have my case, cam boxes, and entire rotating assembly back from EMS. Everything is drool worthy. They did an amazing job cleaning it all up.

Clean and line bore case
Remove headstuds
Replace oil squirters
Rebuild and rebush rods, resize for ARP rod bolts
Mag rods
Mag crank
Polish crank
Cross drill crank
Drill and tap crank
rebuild/rebush rocker arms
R&R cam boxes and clean
Replace timing gears on crank and IS
Balance full rotating assembly including crank, rods, pistons, RSR flywheel, & aluminum pressure plate.

I still have to sort my main bearing and a few other odds and ends before I can assemble the short block. Packed my fan and all my hardware to be sent off to FlyingJay Monday for replating and refinishing the fan. Motor will be nice and shiny when I assemble.

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More progress..

All gt3 rod bearing clearances came out .0021"-.0022". Need to have the rods resized to .0028" and then she'll be ready to seal the case!

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I‘m very curious to see the results of your build as it is very similar to what I have planned for mine.

Just the perennial questions of will straight cut intermediate shaft gears be too loud, which oil pump should I run, and will it make enough power reign.

If i were to do this again, and not in the middle of a pandemic lol, i would purchase the GT3 oil pump.

The JBR gears are less noisy than pauter, and I would not run the pauter gears. Also probably won’t hear them over a practically straight piped 911.

Should make 300hp at the flywheel. Will be taking the engine to Ed Pink for a stand break in and dyno to know exact numbers.

What were your plans?

The plan is alway changing but I have what appears to be a small port 3.0L engine in a 3.2L case with a 2.7RS Distributor so someone has been in there before and built a Franken motor as it had 2.7 CIS on it also. Ran well and made lots of torque but only put down 170whp with thermal reactor delete 3-1 exhaust manifolds and a ‘74 2in 1 out muffler. Won’t know exactly what I have until I open it up.

So far the parts I have collected are

226mm fan that I plan to run with an on engine oil cooler delete.

3.3L Turbo heads to use as a base for porting and twin plug. Probably makes no material difference but RR350 alloy heads should be a little more tolerant to high CHTs. Haven’t talked to Xrteme yet but they seem to have the best porting program.

3.6L Cup Titanium rods. Not 100% committed to running these but maybe getting them X-rayed will Quell any time out concerns I have. Currently they have 40hours of run time in a 997 Cup.

Turbokraft injector blocks and 3.6L intake adapters to run with a 3.6L VarioRam manifold.

AASCO valve Springs and Ti Retainers and some fancy stepped headers I have into a 991 Carrera muffler. It’s the same can as a GT3 muffler but has side exits rather then center.

Plan is assuming I have a 3.0L crank, build a 3.2L or 3.3L Short Stroke with LN cylinders with knock sensor bosses, 10-1 pistons for 130mm rods, and probably a Motec M150 as I want dual lamda, dual knock sensors, and a 2-step/pit speed limiter. With the 3.2L case and a G50 gearbox running a 3.6L crank trigger seems like the easier solution also.

I had a 3.6L VarioRam engine with 993SS cams, solid rocker conversion and a nice set of headers in my 993 awhile back and really liked the engine, it just needed more revs then the stock crank would allow for. Hoping to get a similar feeling out of a 3.2 or 3.3L SS but being able to extend the revlimiter up to 7500-7800 while not having the NVH of a long stroke crank. 3.6L Motors generate so much more NVH compared to the 70.4mm stroke cranks.

But then I see low mileage 996TT motors going for $13k and wonder if 280whp will be enough staying air cooled. It was an awesome car to drive with the stock motor on the street with 15” wheels but I have since tube framed the car put on 993 Turbo brakes 18” wheels for slicks and gone down the G50 conversion path as I wanted grip and brakes in an early car and already had blown up a 2.7L 915 main shaft Autocrossing and didn’t want trans or axle concerns anymore with launching the car on slicks.

Short stroke heads................
 

Thought somebody out there might be interested in seeing the ports (intake and exhaust) on the Carrera cylinder heads that I used on my 3.3SS engine. These heads came off of a track engine and then went to Xtreme Cylinder Heads for a refresh. They are also twin plugged.


Intake
http://forums.pelicanparts.com/uploa...1596420850.jpg

Exhaust
http://forums.pelicanparts.com/uploa...1596420875.jpg

Combustion chamber
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Mahle Low Dome Piston (11:1 CR)
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How’s the mid range, 3-5k on your motor with the 3.2L heads Fred? All the actual 3.2L engines I’ve driven have felt a little soft in the mid range but they all had retarded cam timing trying to squeeze top end power out of stock cams for various class racing rules.

I think the benefit of the full Xtreme weld and D-port machine is to keep the port area smaller then a 3.2L head for better velocity on the low end but still flow as well on the top end for a broader power band. At least that’s my theory on why a small port 3.0L hits so much harder on corner exit and then the 3.2Ls walk on by. With really good heads and the right cam, maybe you can have both.

I'm also going the 997 GT3 Muffler route on my 2.8 build. I also found mine on Ebay. I sold my SSIs and bought Brian's (RarelyL8) headers. I did weigh it.17lbs.
My M&K weighs 15lbs http://forums.pelicanparts.com/uploa...1596427224.jpg
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