Engine Development - Inlet Ports

kirby ,just for the record, why do you think FIA ,Le Mans race , banned the Audi diesels , better mpg, more torque, quieter exhaust,and NO they did not smoke, they won easily. 2006/2007.

all the pussys bitch and moaned, BLA,BLA BLLLAAH.

they immediatly made them add weight ,like 200lbs more,the next year they won again,YUP add more weight,200lbs. the cars were so overweight they lost there road handling abilities.

then they made them run smaller air intake systems, and the crowning touch was a 20% less fuel load than gas/petrol/alcohol cars!

they said fu$kit, any diesel they run today is a beaten down puppy!

as you are aware, the politics in professional racing is as bad as the latest US election!!

Just like Indy did with the turbine cars!
Bob
889076
plymouth, Mi.

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Or the AMA did with Triumphs restricted to 500 cc, vs 750 cc Harleys :slight_smile:

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totally BORED ,so had the V12 out , just having fun!

darn tires are no good ,they just slip and slide around, JEEZ they are 295/35/18 Nitto, i think its the gear ratio in the rear end puts down to much torque!!

OH well iā€™l just have to suffer with it.

Just like Indy did with the turbine cars!

Shameful! Itā€™s appalling to think about where we might be today if Indy
hadnā€™t been so deathly afraid of disruption.

ā€“ Kirbert

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kirby ,just for the record, why do you think FIA ,Le Mans race ,
banned the Audi dieselsā€¦

they said fu$kit, any diesel they run today is a beaten down puppy!

No doubt. Helpful to remember, though, that the rules were what created
those diesel cars in the first place! The class had a minimum weight
regulation, meaning the car couldnā€™t be light, if you built a light car youā€™d just
have to add weight to it anyway. As long as the car has to be heavy anyway,
why not use a diesel engine and reap the benefits of their torque range? If
not for the minimum weight requirement, those Audi diesels would never
have been competitive ā€“ too heavy.

as you are aware, the politics in professional racing is as bad as the
latest US election!!

Iā€™ve all but given up on most racing venues, theyā€™re all hogwash. NASCAR
has Fords and Chevys and Toyotas and whatever, all representing FWD
cars you can buy at the dealer, but there isnā€™t a stock part on them, they are
all RWD racing cars with the SAME drivetrain, the fiberglass body is just a
billboard. And for this coming year, theyā€™re going to a format where each
race is run in 3 parts, with breaks in between where they can interview
drivers and run commercials.

ALMS went off the rails when they started penalizing the winning cars to try
to make things more competitive. The Aston Martins would have kicked a$$
but were carrying around a coupla hundred pounds of excess weight even
BEFORE they had demonstrated their potential! And then theyā€™ve come up
with several different classes for Porsches including some green something
or another that makes no sense to anyone.

Meanwhile F1 outlawed refuelling and penalizes anyone who has to replace
a broken transmission. And theyā€™ve got that silly DRS. Get real.

Indycars are all the same other than 2 different engines and some minor trim
stuff. Drivers like these regulations because it takes the cars out of the
equation and makes it all about them. But racing isnā€™t SUPPOSED to be all
about the drivers, itā€™s supposed to be about the CARS!

I have long postulated that we desperately need a new racing venue with
simple, non-biased regulations that encourage innovation. Three classes:
one prototype and two classes of production cars, all with intake orifice
stipulations that are fixed within each class but will vary according to fuel
used using a simple formula of energy produced per quantity of air
consumed. One production class will roughly correspond to 2-litre NA cars
while the other is for larger-engined cars. All three classes will have to
adhere to the following requirements: 1) The driver will have only a steering
wheel, gas pedal, brake pedal, and a 3-position shifter: Forward, reverse,
and neutral. There is nothing else controlled by humans, either in the car or
back on pit row. However, anything and everything controlled by processors
without human intervention is acceptable. 2) The track will be studded with
those little metal domes that sit about 3" tall, and there will be enough of
them that you canā€™t miss them; you will at least have to straddle some. You
will either need to have 3" of ground clearance or an automatic sensor thatā€™ll
detect the things and raise the car to clear them.

The prototype class should be especially interesting, as ā€“ for the first time in
decades-- moving airfoils on the cars will be legal as long as they are
automatically controlled (the driver cannot fiddle with them). This will
GREATLY enhance the speed, stability and safety of cars at speeds
approaching and exceeding 200 mph.

ā€“ Kirbert

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kirby i agree with most you said!! but i still think you mention to many rules!

you were probably young when the CAN_AM series was running, when 15/20 cars came around a corner onto the starting 1st straight, the Famous 900/1000hp open exhaust would rattle windows a mile away!

and at some tracks local siesmic would go off of impending earth quake!

the ground would actually shake.

the cars were close to NO RULES, many types, many shapes, all kinds of never before modifications and ideas!

so dont you know Porsche shows up with 1500hp turbo flat 12s and flat 16 engines.

most famous Porsche 917 K, easily a 250+ mph car.

that ended the series, every one went home with there tails hanging!

you mention movable wing and downforce devices!

check out OSWEGO SUPER modified cars , not just simple modified,you tube.

i watched many of them , also built engines for some of them back in 1960s.

of sports car at museum, banned after couple races!

you mention movable wing and downforce devices!

check out OSWEGO SUPER modified cars

You posted two photos of Jim Hallā€™s Chaparrals, the cars that introduced
those things! The car also famously had an automatic transmission, freeing
Hallā€™s left foot for operating that wing.

Unfortunately, even the Can-Am organizers couldnā€™t handle innovation,
eventually finding ways of banning the Porsche 917/30. And thus began the
end of that venue.

ā€“ Kirbert

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you were probably young when the CAN_AM series was running, when
15/20 cars came around a corner onto the starting 1st straight, the
Famous 900/1000hp open exhaust would rattle windows a mile away!

the cars were close to NO RULES

Only safety rules, IIRC, no performance restrictions whatsoever. And the
freedom to innovate led to wings, spoilers, even a vacuum car. But
recognize that the same venue today would see cars with 5000+ hp, and no
organization would be willing to host an event; the liability issues would be
overwhelming. Plus itā€™d probably rip up the pavement.

I like the orifice idea, and had great hopes for the ALMS before they went
astray. It gets away from regulations based on displacement, which lead to
unrealistic biases toward oversquare configurations and canā€™t readily be
applied to boosted engines. It also shifts priorities from raw power toward
efficiency, more apropos in todayā€™s world. But the orifice needs to be the
same for everyone in a class, not biased in favor of one competitor over
another. If you keep losing, you need to up your game, not get the
regulators to give you an unfair advantage.

ā€“ Kirbert

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HEY Mark sorry to wander off thread topic!!
we are still looking for more of your project.

Ron

hey mark, been thinkin how to get big power out of a V12 Jaguar! NA, like low end torque, 2200rpm, and hi end rpm and HP 7000rpm.+.
well it seems, that no matter what has been done, the chambers just dont lend themselves to both objectives, as is known the by so many heads mods, 2 valve single cam on bucket, just wont cut it!

but lookin at what the famous V12 of yester yr, RR Merlin and US Alisson. it would requier custom cast heads to fit on a modfied Jag block,(built properly of course). and i got a lot of good ideas on that block.

how about the Allisson 4 valve and roller rocker arraingment (Pentroof/Hemi) chamber can have an excellent chamber/port , setup!!

NOW ,using the HONDA single cam with VTEC control ??? give you the best of a single cam engine, and not blow the width size out of usefullness for packaging in a real car.

Neville take note!
just some mind wandering, i love thinking out of the box, and not spending millions to do it.

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and this basic idea was talked about with myself and one smart cookie tech,at my engine shop back when we were doing engine work, 1989/1992 ,Honda Vtec was a new concept, while on a Genuine real USA Duesenberg engine, it had a 4valve head cam on bucket,twin cam plug centered in chamber, year 1932,supercharged straight 8

i dont think old Jaguar Lyons was going there yet, WW2 had not taken place, to speed up life and death thinking processes.

Neville will, Iā€™m sure, reveal his work in due course. He is developing new V12 heads I believe

how about the Allisson 4 valve and roller rocker arraingment
(Pentroof/Hemi) chamber can have an excellent chamber/port , setup!!

If I were going to the effort of designing my own heads, Iā€™d go with a
3-valve/cylinder arrangement ā€“ two intakes and one exhaust. This yields a
similar swirl pattern on intake and nearly as much flow capacity as a 4-valve,
but the arrangement of roller rockers is much easier, they donā€™t get in each
otherā€™s way. And you can go to the expense of sodium-filled exhaust valves
and only have to buy 12 of them, not 24.

Honda had 3-valve arrangements on some of their engines. My two mid-80ā€™s
CVCC engines both had 3-valve arrangements plus a CVCC chamber, which
ironically involves another tiny intake valve, meaning each cylinder
technically had 3 intakes and 1 exhaust! Worked great, though, and handily
met EPA emission requirements while the Big Three were still lobbying
Congress to push back the deadlines because the requirements couldnā€™t
possibly be met.

Honda also uses rockers with their OHCā€™s. I dunno why all engines donā€™t go
this route. Direct-acting tappets are stupid by comparison. To get sufficient
lift, the cam circle must be large, so the tappet must be large, and large =
heavy! Plus you can use a leverage multiplier to get larger lift out of a
smaller lobe when you use rockers. All in all, Iā€™d bet the total reciprocating
inertia for the rocker valvetrain is at least comparable if not LESS than those
direct tappets. This is all over and above the fact that rockers make valve
adjustment a half hour job, as opposed to the upper engine teardown and
shim fiddling involved in adjusting direct-acting tappets. Plus, rockers let you
locate the valves ANYWHERE, they donā€™t have to be in a straight line under
the cam. When someone comes out with a direct-acting tappet
arrangement, I wonder if that company has lost its marbles.

Honda didnā€™t use rollers on their rockers, at least not on the cars Iā€™ve had.
Each rocker just has a simple curved surface that follows the cam. I suspect
rollers would add significantly to the reciprocating inertia of the valvetrain, but
Iā€™ll admit Iā€™d prefer them anyway. I donā€™t like forceful sliding contact along a
one-dimensional line of contact, no matter how good your oiling system is.
Rollers eliminate that significant wear point.

Iā€™m not sold on the pentroof/hemi configuration. Rather, as Iā€™ve mentioned
previously, Iā€™d at least look into the notion of using a ā€œflat headā€ configuration
while having the valves overlap the outline of the cylinder. Make sure the top
ring on the piston doesnā€™t come up too far, and cut great big scallops in the
corners of the cylinders to clear the valves. I might even go so far as having
to revise the design of the wet liners, if weā€™re talking about the Jaguar V12
arrangement. If you let go of the notion that the valves must remain within
the cylinder outline, you can go with massively larger valves centered farther
away from one another. You donā€™t even care that some portion of each valve
will be shrouded when open, because the opening is SO much larger than
before. Of course, youā€™d have to fab your own head gaskets, but youā€™d
probably be doing that anyway.

ā€“ Kirbert

While visiting Stu Jones shop on the east coast with Norm Lutz, this past fall, the gentleman mentioned he was going to build a 10ltr V12 ''because he could". Stay tuned for that monster. His shop is very impressive and team highly motivated and extremely competent, best JW

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Nice work Mark! Iā€™ve got a broken XJS-C that I want to turn into a track day car (itā€™s an insurance total itā€™s crumpled in the rear). My first thought is how I can get more go out of the V12. My first thought is forcing air in and swapping the ECU, ignition, and fuel system to accommodate for the increase in air and fuel, then picking up a Haltech ECM to manage it all.

I like your approach, elegant and true to form. Keep up with your posts, I am eagerly waiting to read the results.

Cheers!
Mark

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sounds like a great idea, its been talked about for past 10yrs,off and on,.

but no one that i know of has done it, are you thinking turbos?

best V12 for boost would be low compression pre-HE, the later HE engines are very hi compression!

but just maybe ,with some unusual tuning, water/alky would surprise all nay sayers?

i been trying to find,Who built the 1st TWIN turbo engines,NOT counting diesels,.

wiki dont help there info is about 8/10yrs later than what is real!

i was in Daytona BCH. Fl. in summer of 1975, and at Smokey Yunick garage he was doing a dyno test of SBC chevy 258 ", destroker, twin turbo, for INDY race, it made over 1000 crankHP, on methanol!

but some place in my books ,it seems that someone built ,1967/68 Chrysler engine,with twin turbos, also it was intercooled,using some old refridgeration radiators,(you know how USA hot rod guys are at gitter-done ideas).

iā€™ll keep looking.

Sorry guys, Iā€™ve been distracted. I see youā€™ve all been having quite a discussion!

Taken a bit of effort but I now have the full standard pre-HE inlets modelled. For what it is worth.

Havenā€™t looked into it too much so far, and I have a fair bit more work to do if I want to simulate 6 cylinders breathing through the plenum/throttle. This would be the only way to ā€œseeā€ how the small plenum is interacting with the 2.5" throttle bore.

Anyway, prelim data on the port flow.

90mm bore, 70mm stroke. Standard C29347 inlet valve (86gm 41.23 dia). Standard seats recessed 0.9mm into the head. Max lift 9.5mm.

The graphs below show some comparisons. The Brown line is the standard port flow. 133 CFM.
The Blue line is the flow from my Gp C heads with the throttle bodies and trumpets as supplied by the original engine builder (181 CFM).
The Orange and Green lines are the measured vs computer generated flow for the Gp C port on its own (242 vs 244 CFM respectively).
The Yellow line is the theoretical flow of the Gp C port (329 CFM) with reasonably optimised throttle body and trumpet (and a lot of lift!) NB It flows more than the port on its own because of the inlet radius, optimal taper and minimal flow separation.)

Conclusion is that the Gp C arrangement has about 2.5 times the flow as the factory port.

I guess, all things being equal, if the factory was good for 300 hp, then Gp C should be good for 750 hp.

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