Cubic inches: what's the upper limit on racing engines?

[Spencer]

With Fulton and Sonny already building ~870 inch nitrous big blocks, where do you think the upper limit is for racing engines? I've always thought that at some point the law of diminishing returns will take effect, and the weight of the rotating assemblies of these big monsters will negate any advantages of the larger displacement. Thoughts?....discuss.

[Eric68]

Re: Cubic inches: what's the upper limit on racing engines?

Depends on the class in my opinion. I think ProStock is pretty much limited by heads and airflow now more than cubic inches. Top Fuel is limited by traction already even though they decided to play with timing to keep top speeds down.

[fahrenschnell]

Re: Cubic inches: what's the upper limit on racing engines?

I don't think we have even gotten close to the limits yet. ;D

If you look at industrial applications with huge power numbers (30,000HP+) they dwarf even the biggest Mountain Motor. Another good example is the aviation engines of years past. The enormous Rolls Royce and Merlin engines were monsters in their day, and had the industry stayed with piston driven applications would now be unreal.

I realize this may not be exactly the answer to the question, however it does show that displacement doesn't really have a point at which it is no longer effective at producing power.

Seth

[Fordplay0621]

Re: Cubic inches: what's the upper limit on racing engines?

Those old Merlins and Allisons, sound awesome to.

[DanStokes]

Re: Cubic inches: what's the upper limit on racing engines?

Cat makes some Diesels that you can stand up in the bores and clean the piston tops. Why NOT in a dragster??!! A 30K HP Diesel digger - now THAT'S HP!!!

Dan

[Eric68]

Re: Cubic inches: what's the upper limit on racing engines?

Packaging Dan, packaging . . .

How you going to fit a an 8" bore engine in a drag car of any type? Not that I wouldn't enjoy trying mind you . . .

Maybe you could just eliminate the front part of the frame and attach the car to the engine. You know, A-arms bolt directly to the block, head lights to the front of the valve covers . . . ;D

[Brian Lohnes]

Re: Cubic inches: what's the upper limit on racing engines?

Like that trike they built on Monster Garage with the Peterbuilt parts!

I'm with Eric on this....sooner or later you can't make up for the weight of the motor, but I'm not going to be surprised to see 1000-1200 cubic inch drag race motors in the next couple of years. I don't see a lot more happening after that though, at least in terms of drag strip stuff.

Back when the NHRA banned nitro (57-63 I think) multi-engined dragsters came to be the rage. By the end of the Top Gas era, very light single engine cars were right there with the multi engined monsters. One of the baddest twin motor cars was the Nye and Frank "Freight Train". One of the neat things about that operation is that the crew guys would wear conductor caps and overalls when they went up to the starting line. Eddie Hill had a bad mother dragster as well with twin blown Pontiacs sitting side by side, angled out. Apparently he looked between the motors to see down the strip.

Brian

[joebogey]

Re: Cubic inches: what's the upper limit on racing engines?

Hmm... how hard would it be to join two 870" block together???

[Ron Ward]

Re: Cubic inches: what's the upper limit on racing engines?

Packaging Dan, packaging . . .

How you going to fit a an 8" bore engine in a drag car of any type? Not that I wouldn't enjoy trying mind you . . .

Maybe you could just eliminate the front part of the frame and attach the car to the engine. You know, A-arms bolt directly to the block, head lights to the front of the valve covers . . . ;D

I have seen tractors built like that.

[Brian Lohnes]

Re: Cubic inches: what's the upper limit on racing engines?

Just in case you thought I was nuts.....there's a linke to a photo of Eddie Hill's twin engined (and quad tired) front engine dragster below. From the looks of this photo, the framerails (the top ones anyway) actually look like they bolt to the motor, a la, what Ron and Eric have mentioned.

I spiffed up an old Allis and Chalmers a couple of years ago to make a few bucks and I had to replace the clutch. The Allis has a "component" chassis, meaning that the motor and trans are basically the chassis. It was weird "breaking" the tractor in half to get to the clutch. Neanderthal simple, but creepy to pull it into two pieces. I felt like an old timey magician sawing a woman in half.

THIS is crazy stuff.

http://www.dragracingonline.com/firsttime/images/Eddie%20Hill%201961.jpg

Brian

[Brian Lohnes]

Re: Cubic inches: what's the upper limit on racing engines?

Any info on that car?

Looks like a Dragmaser chassis by the barrel shaped cowl area and relatively low seating position of the driver.

3X283 = 849ci!

It's not Ivo's because he was packing 4 Buicks and a Scotty Fenn Chassis.

The guy's head is like 8 inches OVER the top of the roll bar!

Looks like a quick change "rear end" in the front I can barely see peeking out.

Never ever seen or heard about that one. Neat piece of history there! It may have been one of the hundreds of cars that didn't make it through their maiden voyages back then.

[JeffMcKC]

Re: Cubic inches: what's the upper limit on racing engines?

As far as one motor goes, the cubic in is limited by the intake and head flow, and Comp Eliminator will show the Hp per cube side of things it get way out of hand, even with the limits they have

[Eric68]

Re: Cubic inches: what's the upper limit on racing engines?

Brian

Thanks for posting Brian . . . gives new meaning to the term "Dualies"

[Spencer]

Re: Cubic inches: what's the upper limit on racing engines?

Well, it seems to me that in most 'unrestricted' type drag racing classes (like pro mod) the nitrous guys are always slightly behind the blown alcohol cars. The usual solution of the sanctioning bodies is to let the nitrous cars run massive cubes, yet they are still behind. If there's an advantage to 1000 or more cubic inches, surely one of the big $$$ shops would've done it by now with one-off billet blocks, heads, etc. So why haven't they? What will it take for naturally aspirated n20 motors to catch the blown alcohol guys?

[Brian Lohnes]

Re: Cubic inches: what's the upper limit on racing engines?

I think it was either Kaase or Fulton who was working on some 900inch motors for the pulling guys, but that's beside the point I guess.

In IHRA trim the Nitrous guys aren't THAT far off with several of the top runners touching the low 6.0s. Guys like Halsey, and Stoken. I think the biggest factor, and this is going to sound horribly dumb, is the blower combo itself. You can put a blown pro mod engine on a dyno (there are only a few in the country that can stand it. Kenny Dutweiller's and Mike Faucher's are about the only two I know that can handle a legit full house pro mod motor), trying to run a nitrous motor, even on the hariest of dynos is very tough because they run away when the gas comes into play. The blower makes linear power as you spin it, but the nitrous hits like a freight train and really does bizarre things to the dyno (and sometimes itself).

Then there are supercharger dynos. Most of the top running cars either pay a guy like Al Billes to tune their junk, or they literally rent a blower from him. The blower comes in, they bolt it on for the race, then they send it back until the next one. The blowers on those cars are tweaked and tuned and flowed like cylinder heads on a pro stocker.

Add that to the fact that blower racers have like 50 years of research and development work to pull from in their tuning and engine building decisions and it gets easier and easier to see where the advantage comes from.

I guess the other part of the question, being "why doesn't someone plunk a 1000ci motor in one and let it fly?"

If it were only that easy....

The nitrous guys spend ages perfecting their tuneups with the old cubic inch limit and then the sanctioning body raised the limit in order to make them more competitive, which then forces you back to square one on tuning because a bigger motor acts differently then the old one. Meanwhile, the blower guys are forced to knock some overdrive out of their blower and they simple swap ratios in the trans to wick the revs up in order to make more boost. The nitrous guys don't have that option.

I love the nitrous cars as they are great to watch and they put on a hell of a show, but the amount of work and money involved to get one where it needs to be with the blower guys is forcing more and more of the guys over to the ADRL to run with their own kind.

Brian