> > Hi Paul and others,
> >
> > I was quite puzzled on that "fuel cloud" phenomenon, have never
> > seen/heard it before. I'm not sure if it was fully covered before,
so...
> >
> > I found this discussion thread when looking for info about nox
boosting.
> > It's quite good on explaining the thing.
> >
> > "Fuel stand-off - intake reversion - what are the causes?"
> > http://www.eng-tips.com/viewthread.cfm?qid=190526&page=1
> >
> > Originally i got the name for phenomenon from this article:
> >
>
http://www.carcraft.com/techarticles/116_0406_nitrous_350_chevy/index1.html
> >
> > There was some papers listed later on thread:
> >
> > "Intake bell-mouth effects"
> > http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf
> >
> > NACA paper on induction manifold dimensioning
> >
>
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930090861_1993090861.pdf
> >
> > NACA paper on induction manifold dimensioning - pipe length
> >
>
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930084998_1993084998.pdf
> >
> > And later, article about exhaust manifolds
> > http://www.ssheaders.com/header.htm
> >
> > Cheers,
> >
> > Petri
> >
> > I first noticed this around 1965 on 800 HP small block V8 Chevy
> > Chaparral racing engines. The fuel mist was being blown away by the
> > speed of the car. This is what I did about it. I designed this
> > air box and had it installed on the Chaparral 2D and the problem
> > went away. Perhaps just out of sight and out of mind. The car went
on to
> > win the Nurburgring road race in Germany so it obviously worked.
> > As far as I can tell this was the first ram air box on a race car.
> > Now common practice on almost all race cars today. Of course the P38
> > and the Me109 used similar ram air boxes years before.
> >
> > Last year's 245 HP 2nd gen 13B p-port had it. This year's 264 HP RX8
> p-port
> > engine had it in spades. You can find a video of it on the web site.
> > http://www.rotaryeng.net/intake.html
> >
> > This years engine generated 20 more HP. Both in the same
> > 7300 RPM range. Strangely this year's engine had 3 inch shorter
runners.
> > Both had downdraft Weber carbs as did the Chap. 1965 V8 Chev.
> >
> > Although we did not run it above 4000 RPM I did not notice it on Mark
> > Suspinski's 13B p-port engine when running with EFI and 25 inch
runners.
> > That is not to say it won't do it at higher RPMs. Mark should have
> > constructed an air box by now.
> >
> > I suspect it has to due with the carb venturi. Air must be shooting
> > out of the intake runner sucking more fuel out of the float bowl and
> > then back into the engine. I think the engine is flooding
> > with excess fuel. In other words the mixture is probably down
> > around 8:1 or worse. IMHO the engine is drowning with fuel.
> > The BSFC is real bad when this happens and the engine stumbles.
> > So too is the gallons per hour read out from the dyno flow meter.
> >
> > Perhaps one way of dealing with it is to restrict the size of the
> > fuel hose to just enough to get peak power at 12.5:1 I am going to try
> > that on the low pressure fuel injection I am now building.
> >
> > Paul Lamar ...No rotor no motor.
> >
> > ----------------------------------------------------------------------
> > Petri,
> >
> >
> > This report "Intake bellmouth effects" is great.
> >
> >
> > Paul,
> >
> > Thank you for the photos of the Chaparral. At the time of that
> > Chaparral Nürburgring victory (living not far from there) I was just a
> > little boy, but knew the car from my racing car pack of cards (?) very
> > well. Reading my first motorsport magazines some years later I learned,
> > that the win of this single American car with its automatic
transmission
> > versus all the Ferraris and Porsches was really a sensation on that old
> > hilly racetrack. For me this is one of the nicest race cars up to now.
> >
> > Reiner
> >
> > Thanks Reiner. Other than the ram air intake box I had little to do
with
> > that design. I had a lot more to do with the 2F design and that is
> why it is
> > so different than the 2D. The 2D body was done by stylist mostly while
> > I tried to bring low drag aerodynamic principles to the 2F design shown
> > here.
> > It was so different in fact that I had to fight for it within the
> > organization.
> > Some people thought it ugly. Consequently it still looks modern to
> this date
> > 40 years later.
> >
> > The ram air box was built in to the rear of the body. The front and
> > rear panels were Plexiglas so the driver could see through it.
> > The carb air intakes were just above the rad air intakes on either
> > side of the car. The car was required to carry a spare tire by
> > the rules. One could see the reversion by looking in the inside
> > rear view mirror. Also note the oblique mounted radiators. Another
> > feature years ahead of it's time.
> >
> > The 2F set lap records at race tracks all over Europe that stood for
> > a couple of years but the transmission was under-developed and broke
> down in
> > every race except the last one. The BOAC 500 at Brands Hatch England
> > where the 2F won.
> >
> > Consequently the 2F is my favorite Chaparral.
> >
> > Paul Lamar ...No rotor no motor.
> >
> >
> > Paul
> >
> > I just found my book "Chaparral" by Richard Falconer/Doug Nye. This 2 F
> > had really some amazing new details (especially that big rear wing) ,
> > which became common to most racing cars of the next generations. So
> > congratulations for that, even if 40 years to late. Are there more
books
> > (technical side) of that Chaparrals in the US?
> >
> > Reiner
> >
> > The first edition of that book was not very accurate. Both Jim Hall
> > and I called him on it and he modified the book in a later edition
> > adding an appendix in the back with information from me. Pete Lyons
> > wrote a small 96 page book or pamphlet called CARS IN PROFILE NO4.
> > The Chaparral 2, 2D and 2F. Profile Publications Limited, Coburg
> > House, Sheet Street, Windsor Berkshire, England. Whew!
> >
> > Apparently it is very rare as google
> > knows nothing about it. Pete lived at my house in California when
> > he wrote much of it in 1972. As far as I know Pete is still alive and
> > living in Big Bear California. I have not been in touch with him
> > since 2002. Pete is also a pilot. Here is his last known to me
> > email address.
> >
> > Pete Lyons <bigbearlyons@earthlink.net>
> >
> > I have one or two other books on the Chaparral at the hangar.
> > They contain mostly photographs.
> > --
> > Paul Lamar ...No rotor no motor.
>
> Paul:
>
> I have the "Cars in Profile" Vol. 4 that has the Chaparral article in it.
>
> Would you like the rest of the photos scanned in, and the article text?
> I have an old computer, but I can try. :-)
>
> Les Nordman
>
> Thats OK Les. Thanks. I have the book. Perhaps somebody else
> on here would like it. Can you make a pdf of it?
>
> Paul Lamar ...No rotor no motor.

Paul:

Yes, I will scan the articles and its photos and try to make a .pdf of
it.  It will be an adventure! :-)

Les Nordman :-)

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