Some History - Bob Glidden
TURNCOAT AND ALL,
As I mentioned in my brief reply, the heads in question were a set
designed for a blown drag boat application, and Goletta Marine was the
customer. The head castings were designed for Alan Root's all aluminum
BOSS 429 engine packages. The designer of the heads was Tom Roberts who
at the time worked for Nick Arias, in fact Arias was a 30% partner with
Root. Their redesign of the BOSS components began in 1983, and the first
parts were available in late ' 83 - early ' 84. The head redesign reflected
the typical Arias port configuration which favored blown applications.
Blown fuel was what Nick and Alan were after, however, as there were no
takers, other classes were considered, ie. ProStock.
In late ' 83 Alan and I struck a deal to make the heads more appealing
to the Pro ranks. This program included a crash effort to make the standard
Arias Root head work, and I immediately began a redesign of the head incorporating
swirl pads in the chamber, redesign of the inlet port to promote mixture
swirl, and a major redesign of the exhaust side using my "super critical
area rule" to achieve supersonic exhaust flow. The prototype heads were
the std. AR castings with several pounds of my aluminum welding rod used
to reshape all the necessary surfaces. The castings were then normalized,
and re-heat treated to spec. All surfaces were remachined, and the new
chamber and ports were laboriously executed, and the heads flowed as the
formulas' predicted. During this same period Alan and I felt that there
would be a considerable market for finished heads and manifolds, as well
as proper pistons, cams, and advice on rod length, stroke, bore, etc. In
other words, all the right pieces, some assembly required. The Super Swirl
heads (complete), and worked manifold were to be priced at $10 K per "package",
and available in no other form.....remember, however, this was a separate
head entirely from the std. AR 429 "HIGH PORT" heads. In order to get the
ball rolling, we wrote a computer program to allow a multiaxis mill to
"rough in" the chambers, and I spent considerable time at Aerocast in LA
scraping the sand cores to produce 10 pair immediately without welding.
I also began revision of new tooling to allow casting without the custom
scraping, so when I received the heads we at Endyn would do all finish
machining, porting, assembly, etc., and the "super swirl" heads would go
directly to the customer flow sheets and all other engineering data included.
The head package was given part # M-6049-A443* by Ford and included(without)
picture in the 1985 Catalog. We ran our prototype super swirl engine in
November,84, and produced the dyno figures partially quoted in the soft
head article, however, max. power was never revealed until my lengthy book
to Sentiniel, this AM. Bob Glidden heard about the dyno run at the SEMA
show which was going at the time, and wanted to buy the engine, and all
the other hand scraped castings we were finishing. The price was right,
and as the NASCAR programs needed tending , we agreed.....thinking that
our head deal with Ford was intact. Little did I know that Bob had negotiated
to buy out Nick Arias share of AR, and of course he then went directly
to Ford and mandated that the "super swirl" head program be cancelled.
It was and that's that. Bob didn't want anyone else having access to the
same "stuff" he was running, and I can't blame him.
Now I'll address your head related questions: With the exception of
blown applications, ports don't just flow one direction. Intake ports pulsate
back and forth, and exhausts flow backwards too. This occors primarily
at overlap, when the cylinder still has positive exhaust trying to exit
the exhaust port ...where header back pressure is pushing backwards. Now
the intake valve (which is larger in diameter) opens, and exhaust gasses
seeking the path of least pressure take the easy way.....the intake port
"exit". This is not a good thing because besides turning the intake port
black "reversion" also contaminates the intake charge with inert gasses
which will not burn again. My studies showed a direct correlation between
low lift intake flow and reverse flow.....The better the low lift flow
on an intake port, the better the tendency for reverse flow, or sucking
exhaust. I designed my intake ports to not flow worth a shit at low lift,
and also to not flow backwards. I'll not detail how, but the approach to
the inlet valve seat, and its blend to the chamber are how it's accomplished....remember
the seat is only the 45 degree angle that's ~ .055" wide. were not talking
about the seat ring itself. The assymetric shapes I developed for that
area and the last .5" of the intake port (the wierd valve job) are why
the port doesn't dare flow backward, and as for low lift flow......study
the piston velocity when the valve's at .150" or less. You'll find that
it's so slow that the port's not being sucked on at all(relatively speaking),
so big flow #'s at low lift wouldn't do you any good anyway. If I had known
how to design an intake port that flowed 0 cfm. up to .150" lift, I would
have, but all things considered my "weird seats" worked well for their
time.
Exhaust ports: Read my Re. to RX first. I've never had much luck with
performance of engines with no exhaust valves, so I've never been inclined
to design exhaust ports without valves included. All I'll say is that the
some flow attaches itself to the head and stem on the exhaust side, so
the valve is somewhat like a guide for flow. The thing you're missing when
flowing with no valve is that the valve stem represents part of the cross
sectional area of the port, and, as previously stated areas are critical
when dealing with velocities over mach 1. My port phylosophy has always
been to calculate how much air a given displacement engine needs to run
at a given rpm range (taking into account the many variables such as bore
/ stroke / rod length, and of course rules), and design a high velocity
intake port that's not too large or so small that the velocities will cause
separation of a well prepared air / fuel mixture. With valvetrain life
in mind, I also attempt to achieve highest flow rates at crank angles where
piston velocity is highest (greatest sucking power). If you can obtain
90% of your max. flow rate at mid lift, you don't need to run a cam with
spring killing lift. As for the exhaust side, lalve lift and the additional
heat kill springs, so the more you can flow, the less lift is needed, and
if it's real good you don't need to open the exhaust valve before BDC on
the power stroke, releasing that last bit of cylinder pressure pushing
on the piston, and you can close it earlier too. Most "head experts" agree
that the exhaust should flow 80% of the intake, and assuming that they're
talking flow with the manifold / injector installed, and the header on
the exhaust, that's ok. But if I can design an exhaust port that flows
twice the intake port flow, I will, because it allows you to run less lift
and duration which makes springs happy, and on an engine like the Ford
BOSS 429 remember the exhaust rocker arm is about 5" long, and I don't
care what you make it from, all that mass takes considerable spring to
control, and the less you move it the longer all the parts last. Over the
years I've had customers go in and fuck up my ports so the flow will be
less allowing them to run the same cam they used to. What a world.
I was diagnosed with cancer in Sept.1979, a great thing to find after
winning Indy 3 months earlier. Two years of continuous chemotherapy and
I achieved remission, it bit my ass again after concluding the rules breaking
Toyota program. Another year of chemo. and four weeks of radiation and
they haven't killed me yet. One reason I'm still here is that after cutting
off the bull shit with the press, and I've been able to pick and choose
what I work on and who I work for, and for the most part I set the rules
and the schedules.
Now I appreciate your support, and I enjoy fielding some technical
questions for you guys, but I don't and won't go through this bull shit
of being placed under a fucking microscope, and having to justify who the
hell I am or "am not". As your second remission doesn't last as long as
your first, that puts me 3 years "over due", and I've had so much fun with
doctors, I'm gonna roll with it this next go-round, and try to leave the
world a little bit better place than when I came . I'm tired, I'm irritated,
and I'm pissed, and now it's time for me to quit typing and get back to
something more productive than trying to convince people that I'm alive.