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
Click the link at the bottom for more pics...it IS a gorgeous hunk of
It's pricey (around $3000) but damn, that's some nice work they did
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
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
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...
William R. Walsh 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.
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
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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