Found a true 12-port head for the Chevy Inline-Sixes...

For anyone interested (Like me...) I was searching for a cylinder head for a 292ci L6 that would enable me to do MPFI. I'm interested in FI for many reasons, one of which being the easier tune-ability when using
some sort of forced induction.
The only obstacle I saw was the siamesed intake ports. While they flow pretty good, and would work just fine for TBI or carb'd applications, MPFI would be tough without somehow separating the ports.
Well after reading the "Chevrolet Inline Six-Cylinder Power Manual" I did some searching for some names that were in the book, and found this:
http://www.sissellsautomotive.com/cylinderheads.html
Click the link at the bottom for more pics...it IS a gorgeous hunk of aluminum.
It's pricey (around $3000) but damn, that's some nice work they did there.
~jp
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Jon, you just stepped up to the big time. The inline sixes can make bunches of torque and horsepower, it just takes money.
George
Jon R. Pickens wrote:

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Heh... Well, I'm much more interested in the low-end torque than the HP. After some serious thought, and factoring in that even a lowly 3000rpm is faster than my engine ever turns, I decided to abandon my 350. Now, I will re-cam it, and get it running good in the short-term. But the long-term plan involves a 292. I've never seen a K5 sporting a 'Six' and I think it'd be unique, cool, and hopefully a real stump-puller too ;-)
It's definitely something I'll tackle in stages. Probably starting with a bone-stock 292, except with TBI rather than a carb. New 292 long blocks were available (and may still be) as of a few years back. That nice head would have to come later, especially when you consider that it costs more than a good long-block engine does!
But I can *very clearly* imagine that with a MPFI setup and a turbo...now I just need to get a 2nd job to finance this sick obsession...
~jp
George wrote:

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Hi!

Hmmm...out of stock until Summer '06? It's come and gone. I wonder if these are still available?
If you happen to find one, I think it would be an interesting project to watch. Keep us posted!
William
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Yeah, I noticed that too... At $3000 that head isn't a huge priority. And as I don't even have an engine yet to start working on, it's far off in the future.
I did find mention of someone using only 3 injectors in a MPFI setup with the stock head. Each injector was pulling double-duty, handling 2 cylinders. I'm sure it'd require an ECM custom-programmed to fire each injector twice per every 2 rpms of the crank rather than once, and finding injectors that could handle that would be necessary.
Mainly, I'm looking at the design of that 12-port head. I know a machinist, and I'd like to speak with him about making something like that from scratch. The ports aren't as complex because they're so high up (less extreme angles) and they're perfectly round.
I also didn't see any numbers on the website about port volume, and that would be something I'd look closely at. The high intake ports on that head would seem to flow better without extensive porting simply because of the fairly straight shape--the air doesn't have to make any really extreme turns to get down to the valve. It's a very simple design. I think a reasonably skilled machinist could make something similar for well below the cost of the Sissell head. The main objective in designing it (as with any head) would be getting max airflow through the smallest ports possible. I'm *quite* willing to sacrifice power above 3500rpm if it means getting a high peak torque down low where I want it (idle to about 2500rpm... I cruise at 80mph under 2000rpm).
Unfortunately, nobody seems interested in increasing low-end torque ONLY. It's a subject gets little to no attention. Every power-increasing mod on the market seems to boost power, but usually it's found by pushing the peak HP further up in the rpm band. I can't find ANY resources on building stump-pulling motors. I only find really general info, like smaller ports for increased velocity, low-duration/low-lift cams with wide lobe separation for increased cylinder pressure at lower rpms, etc... I really wish I could find a guide of sorts to building low-end torque, with no real focus on high-rpm HP. Even the off-road magazines don't show this stuff. You'd think magazines whose target demographic is folks that do low-speed activities like rock-crawling and trail-driving would come up with something, but no...
I smell a new thread coming in the near future...
~jp
William R. Walsh wrote:

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Jon R. Pickens wrote:

There is some pretty good info about buildind for torque,with recommended cam shafts,induction etc,with specific mention of the 292 in a book titled "Chevrolet+GMC Light Truck Owner's Bible" by Moses Ludel. It even has a G.M.part number:12363286.
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Really? I've heard of that one, but heard that it was really general and not specific enough. I'll check it out though.
Right now I'm re-reading the "Chevrolet Inline Six-Cylinder Power Manual" by Leo Santucci. It focuses much more on high-HP builds for all-out racing, but there is still a *lot* of good info in there.
I won't be able to go all-out on my first attempt, so I'll be using a stock head--probably a 194 head for more compression. I may send it to Sissell's for port work, including welding in a "lump" and reshaping everything... It'd end up with a smaller port volume but with better flow. It's much cheaper than the 12-port head. It should produce better low-end torque than the stock head by far.
That, a good cam ground for my exact application, and a carb intake manifold topped with a TBI unit would be a good starting point in my opinion.
~jp
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Jon R. Pickens wrote:

-------------------------------------------------------------------------------------------------------------------------- Yes you're right,there isn't a lot of specific recommendations but it sure is a good read.It covers gear ratios,tire diameters,correct cam characteristics ( with specific brand recs) and other valuable info. The entire book is extremely interesting and useful IMO.
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Then I'll most definitely check it out. Thanks for the recommendation.
~jp
brianorion wrote:

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