Drag racing engines

[NBM326]

I was looking at one the other day, and I still cant quite figure out how they get so much power out of those engines. They are large, yes. But they arent that large. 6000 hp is alot to get out of an engine that is restricted to 500 ci. Anyone know how they do it?

[Anzeige eBay]

Hallo NBM326,

 

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[Seb2]

You know topfuels have to change sparks between warm up and run. These engines are just made for dragracing. With special caractre. Its still large V8 supercharger and much NOS. You could build a street engine on a 454 engine and easy get over 1000rwhp and be able to run it on street. But on real dragsters everything is very special.

[NBM326]

Yea they also run about 90 percent nitro. Which im sure is pretty helpful. I think the engines they use may be marine engines (as in for boats) If you look at the cylinders, you could probably shove your fist down it if you wanted too. The engines are huge. But still, 6000 hp is alot for a 500 ci block

[djfux69]

their engine are run off of a different type of fuel. nitro. also their setups are different. they have 6 clutches, 4 of which have to be replaced after each race. if i find the article ill post again its huge.... they are beasts . they suck up a lot of fuel too. something like 50 gallons a mile. crazy stuff ill try to find the article.

[thepolarfoxqx]

these motors are balanced to rev up to 10,000+ rpms - on a pushrod layout, they are pumping 90psi of boost from the supercharger (keep in mind the 127hp/l Audi TT is running well under 30psi boost). There is a lot of NOS, the nitro fuel is huge in it, but they also push the mixture so rich that they literally pump raw fuel out the exhaust. The engines also have to be very very fortified to stand up to all of this.

If durability were no object, neither was money, you could make just about everything but a lawnmower put out that kind of power.

[izzyloveslizzy]

This may be un-related, but did you ever see that episode of Junkyard Wars (I think it was Junkyard Wars anyway) where they built drag racers with normal engines and one team's engine's forward transmission completely stopped working so they flipped the engine and used the reverse gear (which was the only gear left) as their forward gear. That was fun to watch. Makes me wanna build a drag-racer with a lawn-mower engine.

[thepolarfoxqx]

flipped the engine? why? ouch.

a lawn mower engine, that's productive. Get all 800ccs of side valve action going for ya.

how about - ford 351 bolted into lawnmower - that promises fun!

[izzyloveslizzy]

LOL. Yes! Then I can "hitch my wagon to a star"! Heheh! No seriously though, I can think of a few safe modifications that might make a 50+BHP lawn-mower engine produce up to 100HP. For a super-light drag-racer (I'm thinking all aluminum structure) that shold be fairly OK. Especially cool considering how it's an engine that's not meant to be there.

By the way you missed a great episode if you didn't see that. they flipped the engine the other way around so that the reverse gear would be like 1st gear forward. Don't you understand? With just a reverse gear, they could only race backwards, which they tried. But when they flipped the engine and reattached it, they could use the reverse for forward. Crude, but necessary. The other gears (forward) didn't work, so it was the only option. Quite a good idea if you ask me.

[thepolarfoxqx]

hack engineering has its place, i am always impressed with it, just not under my hood. Lawn mower engines are designed to turn no greater than 3,600hp, you can always modify them to do better, it is not always solid though. I have a freind who got the briggs and stratton I/C 5.5hp for his go-kart, and now it pumps out 13hp, and has an average time to overhaul of no better than 20 hours. yeah - its like that.

[izzyloveslizzy]

Yes but it doesn't have to be so low-tuned. One thing that (at least with some mower engines) is good is that they have a relatively linear power-delivery (at least that's what I've heard). If after tuning, the same linearity remains (which I expect it will), then booya, you've got yourself a good enough wngine to make a sports car with. I know it sounds ridiculous, but it's fun. Torque delivery shouldn't be that bad either.

[Anzeige Amazon]

Hallo NBM326,

 

schau doch mal hier zum Thema Zubehör für Motorsport (Anzeige)? Eventuell gibt es dort etwas Passendes.

 

Auch interessant: Der V16 Motor zum Selberbauen (Anzeige).

[thepolarfoxqx]

the basic archetecture is so primative it isn't funny. Power output is really limited, and the linear power delivery comes from being tuned for very low rpms. My freind's gokart is anemic and uneven until well past 5,000rpms, and starts screaming shy of 10, see why it only lasts 20 hours?

[izzyloveslizzy]

How much power did it have to start with though? More powerful mower engines are also usualy better tuners. You could even put'em in small cars. Not very reliable, and the milage may be nonexistent, but it's just the fun-factor I'm after. If it works, why not? If it doesn't, it'll be a good experience.

[thepolarfoxqx]

you want to spend your time tuning Briggs and Stratton instead of BMW, go for it. If nothing else, it will be fun. I tried building a go-kart powered on a jet engine made from a turbocharger. i may try that again soon.

[izzyloveslizzy]

Hey if you do that again, keep me informed about it. I'm very interested in that. I liked it when I heard of the first time you did that. I'd join you in the modification of the go-kart but I probably won't be able to do anything other than send you some crazy ideas. That's about it. I'd like to see pics and videos of this too though. I once thought of making a propeller drivengo-kart (I wanted to use a Cessna engine) but it's too heavy and won't easily fir. Besides it's risky and tricky. For something of that size it's be easier to go with a turbo-prop engine or two, on the sides. I couldn't get the engine anyway so that was a no-go. I have another idea as well, for a racing car that is a half-breed of an F1-car and a go-Kart, with a fan facing forward and down, inside the car, 60º downward, sucking the car to the ground. It's harsh though, once you figure something out and want to lay your ideas down but you don't have the resources or money.

[Fael-Inis]

This may be un-related, but did you ever see that episode of Junkyard Wars (I think it was Junkyard Wars anyway) where they built drag racers with normal engines and one team's engine's forward transmission completely stopped working so they flipped the engine and used the reverse gear (which was the only gear left) as their forward gear. That was fun to watch. Makes me wanna build a drag-racer with a lawn-mower engine.

They didn't flip the engine, they flipped the rear axle But that was an awesome episode

[thepolarfoxqx]

man, i wish i were half as smart as those people they find to put on battle bots. If my parts don't fit together just so, I go nuts.

I once saw an episode where they made fire-fighting boats. One team made one from an old land rover and oil drums. They used the land rover engine to power wheels (which could barely move them through the water) and to drive a centrifugal pump - which was awsome). the other team had a row boat and a piston pump - which was good for nothing.

I wondered why the team with the slow boat with the incredible pump didn't just use their killer blast of water to knock the other team off their boat and win by default. Probably would have disqualified them, too bad, I would have liked to have seen it.

[riconijhof]

Heh lol, I saw that episode too. Would have been funny thou.

[izzyloveslizzy]

They didn't flip the engine, they flipped the rear axle But that was an awesome episode

Sorry, yes that's what I meant. I know they flipped the axle. Believe me I'm not that dumb!

And by the way I wanted to mention another episode of Junkyard Wars (or, again, at least I thought it was Junkyard Wars), where they modified the underbelly and what-not on a Mustang to make a big lawn-mower out of it. I liked that one too. I wish I was like those people. I'd love to mess with cars and turn'em into boats or mowers or whatever.