Engines

[valenti]

So listen all you large displacement, big horsepower, American engine guys. Is it true that in otto cycle engine theory, that a large portion of the fuel injested by a high performance engine (and when I say High performance, I mean extremely high HP to Displacement figures as in a straight line motor, or even a roundy-round motor)...that most of the fuel is going through is just doing cooling to prevent detonation and only a small % is actually being used to convert chemical energy into mechanical energy. I know that those engines are very ineficient in terms of fuel to HP conversion, but that's one of the reasons that they CAN generate such ridiculous HP figures...anyone?????


valenti

[4x4]

The old girl has lost her mind !!

4x ;) :D ;)

[Chief]

Hey, Val, how are ya? Glad to chime in on a hot rod question- at least I know a little bit about it! You're right about the fuel cooling, particularly in the case of a nitromethane-fueled drag race engine, like in John Force's car. It will use fifteen gallons of fuel in what amounts to about two minutes of idling and 5 seconds of full-throttle operation. The engine is 500 cubic inches and it will produce in excess of 6000 horsepower- amazing for an engine of this size with all of the inherent friction and pumping losses. Timing in excess of 60 degrees BTDC is commonplace.
Nitromethane fuel is much less efficient that ordinary gasoline- but it carries its own oxygen in molecular form. The supercharger is used to ram more fuel into the engine as much as it is used for air. An engine, being basically a big air pump, responds only to the amount of fuel/air mixture being introduced to it- that's the reason the fuel line on Force's Mustang is THREE INCHES in diameter, and the pumps can easily flow over a gallon per second. The fuel system is by far the most critical element of one of these engines. As to your question about cooling, the flame front of the nitro fuel is in excess of 7000 degrees, so they need LOTS of cooling. Those engines get used up awfully quick- nothing can stand that much heat and cylinder pressure for very long. Anyway, take care, old gal- I'm goin' to go get some work done (for a change!) :D Chief

[mdeven]

Holy shit!
Real, intelligent conversation....
You guys are gonna give us a bad name....
Gotta go change the gun on my mig welder.... Later ya'll....
Mark :cool:

[Chief]

...Mark? A new chassis for John Force? :D :D Love hot roddin, wish I was as savvy with these old cards. But, you run propane in your diesel pickup- you're crazy as those drag racers....Chief

[mdeven]

Welding up some aluminum for a small boat....
Then I have to make a trailer for it....
Mark

[bigdaddym]

dodge is thinkin of producing a motorcycle. it will have the viper v-10 strapped to it. they say 500 hp and 300 mph. streetable.considering production 2005. btw.......has 4 wheels (twwo front......two rear) very close together on independant suspensions.going to use forklift drive chains. jsut a tidbit. Big D

[KHJ]

correction they have produced it !!!
but only 1 they are considering producing 10 for collectors but never ever will it be mass produced

(damn I think I might have just gave away where I work)

p.s. it nis not a dodge it is a Daimler-Chrysler superbike

p.s.s. it is not streetable the turning radius is about the same as a 18-wheeler

[valenti]

OK thanks everyone. I was really interested in that whole fuel for cooling thing. Once the chief got into nitromethane, and molecular oxygen, that was it for me. Gotta wonder what the EPA thinks about 3" fuel lines and 15 gallons/125 seconds of operation. I guess it's the NHRA's fleet average that they look at though isn't it??? hahahah

thanks guys

two of my favorite sounds...Live Music, and big crazy engines. Little chevy 302 going about 7 or 8 grand sure sounds sweeeeet.

Not so CM valenti

[Chief]

Valenti, 8 grand, a little Chevy 302? That's all? Must be one of those Canadian versions...we spin the shit out of 'em down here. 500 inch Pro Stock engines are hittin' 9500- how sweet THAT is!:)

[valenti]

9500 shit that's 13000 Canadian...that's gotta be Sweeeeet

valenti

[Chief]

Forgot about the conversion factor, Val...Had a Yamaha that would actually do that, though...ahh, I'm gettin' the fever...BTW, are you up with the latest temp? Everybody's bitchin...I'm one up, one NFG with it. It's a card looping son of a bitch, for sure.

[valenti]

Yes I've got a couple of things working. One is freezing every 30 minutes or so, the other is an Activation which is working pretty good. And yaaa...I hate those card loopers.

valenti

[valenti]

Your not talkin about 5000rpm on the ZX6R are you???that thing shopuld go to 10000 like nothin...in fact I think that engine does about 95 hp at 10000 yes, no????

valenti

[Chief]

...you goofy Canadian, you. :p 001438's talkin' piston speed in feet per minute, not revolutions per minute. Big difference, Val..10000 feet per minute would launch that joker into outer space!

[lifted_99]

actually your piston speed in feet per minute is as follows

1.72 x 2 (since a full revolution is up and down) = 3.44

3.44 x 14500 = 49880

49880 / 12 = 4157 feet per minute


guess 28000 is out of the question huh

oh well just saw that mistake and thought i would elaborate

[lifted_99]

ohh and a tid bit on the nitro drag engines.... fuel is injected in three different spots into the motor... before the supercharger, after the supercharger, and directly into the combustion chamber. the engine won't even start of the nitro fuel mixture... alcohol is used to get them fired...... if you ever get a chance to get near one while its running.... take a deep breath :) it's good for ya

[4x4]

Ya , then you have Nitro farts for a week after !!

4x :D

[Chief]

Nice to talk about nasty motors instead of nasty scripts for a change...You're right, Lifted_99..sometimes they even just use pump gas to light 'em off. Nitro is a very slow-burning fuel, and that's why you see the flames from the zoomies at night- because a lot of it is exploding in the header itself. That's also why they're so stinkin' loud. (I'm having a sexual experience). Also- with the advent of the high volume fuel systems so much nitro runs into the cylinders that if it was used to start 'em, it would put the engine in hydraulic lock. I've seen it blow'em all to shit right in the staging lanes until they finally figured out what was happening. Anyway, I can't wait until the O'reilly Nationals come around again- whap,whap- I can hear it now..ahhh...

[valenti]

Hey Chief...that's Mr. Goofy Canadian to you buster.


hahhahahhhaha...feet per minute...got it now.

CM valenti

[Chief]

Yeah, they're getting fuzzy headed over this locals deal. Trust me, it's gettin' ready to be fixed... I don't think I need to know any more about engines than I already do- just like talkin' about 'em. I've built 'em, sold 'em, raced 'em, studied about 'em for over forty years now, so I'm about to learn the difference between a spark plug and a dipstick! I promise you, I can fix your engine a lot quicker than I can fix your HU! Haven't got too deep into the computer aspects of modern engine applications- I'm more of a throwback to the old days when you hot rodded 'em a little differently than now. What's your background, double ought? You seem well versed...