Drag racing engines

NBM326 · 01-16-02, 04:00 PM

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?

Seb · 01-17-02, 06:39 PM

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 · 01-17-02, 06:45 PM

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 · 01-03-03, 06:41 PM

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 · 01-04-03, 06:04 AM

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 · 05-14-03, 06:18 PM

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 · 05-14-03, 06:23 PM

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 · 05-14-03, 06:54 PM

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 · 05-14-03, 07:44 PM

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 · 05-14-03, 08:16 PM

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.