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Stan, sounds great and should go like a scalded cat.

I'm hoping my engine will be fired up for the first time this week (fingers' crossed). The last hurdle was getting the Porsche starter rebuilt and back in the car.

 

I'm also going with centered dual exhaust tips.  How did you route your pipe(s)?

My duals will come from their own 'out's in a single Magnaflow. One pipe will travel directly to the back of the car from the muffler, while the other will head towards the front of the car, turn and go over the tranny, then turn again and head towards the back of the car.  They will both meet at the center.

Originally Posted by Stan Galat, '05 IM, 2276, Tremont, IL:
Originally Posted by Bob: 2015 Intermeccanica S6:
Originally Posted by DannyP:

That is great Stan! Sounds very nice!

 

Of course you get Mr. Wizard points for the exhaust cutout!

Hmmm.  Wonder if Henry would do that on my new build?

 

Sure he could. It's only money....

Oh, you hit the nail on the head there, Stan.

 

Originally Posted by Rusty Smith - 2002 IM - Southern, CA.:

Stan,

 

Now if you would please document this setup so the rest of us can duplicate without going through the painful process that you did!

This project started for me in the fall of 2013, and just fired up this weekend, so there was nothing fast about it. I have a spare 2110, or I'd have missed an entire season.

 

To really do this, you pretty much need to be ready to start over with the engine. The engine needs to be designed around the twin-plug heads in order for it to mean anything.

 

WAY smarter guys than me have been doing this for years with big-bore 911s and Type 4s. Rich's old "Oscar" 2666 Type 4 had a twin-plug set-up, but it was an early effort by Jake Raby with both plugs on the same side of the combustion chamber.

 

The theoretical ideal is to keep the plugs spaced apart in the cylinder, with one set on top and another set on the bottom. The idea is that two flame fronts promote faster and more complete combustion in a high compression environment. Len Hoffman from HAM says that typically a guy can run 1 full point more static compression with a Type 4 twin-plug set-up.

 

The benefits increase in larger bores. My engine is a 94 mm bore, which is pretty minimal for this. I'm running an FK8, which generally likes 9.5- 10:1 static compression in street applications. I'm running 10.5:1.

 

The heads are the first order of business. I really wanted CB Super Pro heads, but CB (rightly) had no interest in trying to do the work. I found a guy on the Samba who owns a foundry in Wyoming who told me he'd done "a lot" of these conversions. I bought a $1000 set of heads, and the additional expense port-matched manifolds and drop-shipped them to Wyoming. To make a long/sad story even more long and sad- my heads became a set of really expensive scrap.

 

Fortunately, I contacted Michael Ballard at RevMaster. RevMaster does aviation twin-plug 049s, which I knew about- but all the literature shows them with a semi-hemi combustion chamber, so I hand't given them a second thought. When my Super Pro project went sideways, I contacted Mike and found that they could do the twin plug set-up in a wedge combustion chamber. They CNC the heads, so I chose a port that was set up more for velocity than total flow, but I suspect what I've got will flow about 180 CFM. I've got 42 x 35 valves, if memory serves.

 

From there, I sent the longblock and heads to Blackline racing, and had them do the build, keeping my bottom end (with a new cam), and installing the new heads. I retained the dry-sump set-up I'd done several years ago.

 

The ignition proved to be the hard part. Initially, I was going to do Mega Jolt stuff, but the spark table is pretty small, and EDIS stuff is going away anyhow. I bought everything I needed (except the trigger wheel) for a full Micro Squirt set-up, with the intent of only using the spark for now, but adding EFI down the road. The trigger wheel was going to have to be custom, because the crank pulley is very small (for the dry-sump). After spending all the money on the Micro-Squirt stuff, I decided that part of what made this cool to me was a big-'ol bundle-of-snakes distributor and two coils hanging off the shroud- like the big-boy 911 twin-spark stuff.

 

CB had just come out with their "Black Box" ignition controller, which uses a locked out 009. I contacted Mario Vellota from the Dubshop (he supplied all the Micro-Squirt stuff) about converting the "Black Box" to twin plug with an additional coil driver, so I wouldn't need an extra pick-up. He agreed, and did the work. I got a spare module converted, since "you never know".

 

I knew from researching this that Clark Callis from Awesome Powdercoating had tinkered around with converting an 009 to use a late '70s, early '80s Datsun twin-plug 4 cylinder cap and rotor, but had had issues with the twin pick-ups. Since I was only using one pick-up, I reasoned it wouldn't be an issue. I discussed the situation with Clark, and he converted one of my 009s to use the Datsun parts.

 

From there, it was all just time in the garage, putting it all together. I bought a 100 ft roll of spark-plug wire, and a ton of terminals and boots from my FLAPS to build the wireset. The vacuum manifold is a neat bit of kit I brazed up.

 

The headers are from A1, modified by me to clear the dry-sump. The exhaust is the 5th one I've built, so I'm at least used to it (if still not any good at it). I had the header coated, but not the exhaust- I'm just using rattle-can high-heat paint on it until I know we're good.

 

In short, it's a very long process, but not impossible. Over $2K could have been saved by not having abortive starts on stuff. The whole thing would've been easier and better by just doing a wasted spark Mega-Jolt set-up and crank-fire, but I LOVE the old-school look of the distributor and coils.

 

Madness doesn't even begin to cover this.

Thanks, Rusty. I'm pleased with the result so far.

 

Thanks for noticing the tin and seals. I made the rear breastplate and surround tin out of .063 AL. I wanted to use felt as the seal, as I've never been wild about the rubber seals, which don't really hold up to the exhaust heat.

 

I left a 1/2" lip looking down on both the engine tin and the surround tin. The felt is glued to the engine tin. The hard part was the curved pieces- this required welding a 1/2" strip to each piece of tin, looking down, along the curve. I had the strip tacked with a TIG, then used AL brazing rod from a radiator supply place in FL to attach it along the entire length. The breastplate took me 3 hours or more to braze the stupid thing on, so I took the second (surround) piece to a radiator shop to have them do it. The pieces are powdercoated, then topped with truck-bed liner. I've got a 2000* 1/8" thick thermal insulation covering the entire bottom of all the tin to protect the truck-bed liner, and keep the heat out.

The pulley ratio is the same as stock, but it's accomplished by means of smaller pulleys. With a dry-sump, the pump occupies space normally reserved by the crank pulley. The crank pulley HAS to be smaller to clear the pump (which sticks out about 4" from the case)- so in order to keep the ratio the same, the top pulley is smaller too.

 

I wasn't wild about the serpentine set-up, but it's proven to be reliable on two trips of 4000- 5000 mi each.  

The only real benefit a serpentine pulley system provides is lightening you wallet. What's the setup worth- $200? Yeah, as Lane said, it looks cool and is easy to adjust (not that the stock pulley is that hard to take apart and either add or remove a shim or 2) but it doesn't really do any more than what the stock parts already do, which is spin the generator/alternator (and fan on the end). Now, if you're ok with that, then spend away!

Forgot to say- 

 Stan- Love that engine pic! The way you did the rear tinwork looks so right, and the 2 coils and all those wires coming out of the distributor; that's pure engine **** right there! Can we see a pic from a little further back (not quite so high) that includes the carbs? Where did you mount the CB black box?

Originally Posted by ALB:

The only real benefit a serpentine pulley system provides is lightening you wallet. What's the setup worth- $200? Yeah, as Lane said, it looks cool and is easy to adjust (not that the stock pulley is that hard to take apart and either add or remove a shim or 2) but it doesn't really do any more than what the stock parts already do, which is spin the generator/alternator (and fan on the end). Now, if you're ok with that, then spend away!

I can't understand why someone hasn't developed a serpentine pulley system with a spring compressed pulley.

A serpentine pulley system that needs to be adjusted by moving a bolt is, in my opinion, a waste of money, but each to their own......

 

Last edited by Ron O
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