Strega Questions: Can It Be True??

[speeddemon]

Re: Strega Questions: Can It Be True??

Actually, this is not the case. While Roush has done some repair work on racing cylinder heads, most are built or rebuilt by the handful of Merlin builders still in the business. In fact, I know of only one head on one racer which was originally built up by Roush's shop.

Mickey Rupp was the guy who convinced Rousch to get involved. But the 'old' part of the Merlin wasn't strong enough to keep up with the kind of power the 'new' Rousch parts were making....so Mick went through a lot of engines, and Samurai crashed before they could really do anything with the program.

[Unregistered]

Re: Strega Questions: Can It Be True??

Mickey Rupp was the guy who convinced Rousch to get involved.

Just a footnote: Some of Mickey Rupps parts are currently flying on Miss America (scoop, ailerons, wing tips) and Merlin's Magic (coolant door).

[glider90]

Re: Strega Questions: Can It Be True??

I had heard that one of the Roush Industries divisions was actually re-casting cylinder heads, apparently I was mislead?

[matt]

Re: Strega Questions: Can It Be True??

i have heard of roller cams made by roush for the merlins, maybe cylinder heads aren't far off.

[Ron101502]

Re: Strega Questions: Can It Be True??

I stand corrected on the Merlin head. The demo head they had at OSH must be the only one Rousch made. Didn't look like anything that couldn't be re-produced by any speed shop.

[Peashooter]

Re: Strega Questions: Can It Be True??

How about a "top-fuel" technology V-12? It would only have to turn 4-4,500 rpm and would make monstrous, reliable power. Tim Adams, what are the performance specs on a current technolgy top-fuel engine, i.e., power, rpms, longevity, etc? Sounds like a Kraz cartoon needs to be done! Peas

[marada mx3]

Re: Strega Questions: Can It Be True??

Peas:

Top fuel engines are putting out around 7000 - 8000 HP, according to some of the drivers, crews, and commentators. Those are the figures that I've heard repeated over and over. No one has ever dyno'd a top fuel engine. These are calculated guestimates.

The rpm range hasn't changed much: still 8000 - 9000.

The big problem: they only last 5 seconds. Sometimes less. They start eating parts very quick when all the parameters are are not perfect.

These engines make sooooo much power because of the amount of fuel and air they run through them (nitro and a supercharger). They run a good deal more fuel through them than the engine can burn. Helps for cooling.

Hope this helps.
Tommy

[Dago Dog]

Re: Strega Questions: Can It Be True??

Back to the topic at hand. FINALLY Dago can have some fun swappin' it with another Stang . 3 top contenders and a couple of sleepers makes for great racin'. Maybe we'll get the Witch to go all out and Skip to uncover the REAL DAGO horsies in 05. But will the BARE hold together? I know let's all chip in for an extra 55 gallon drum of that externally lubricating stuff to make a race of it. Reno 05. BE THERE!!!!!!

[AAFO_WSagar]

Re: Strega Questions: Can It Be True??

Sounds like a Kraz cartoon needs to be done! Peas

Yea! IT's good to see ol' Krazly back... I can't wait till he gets back up to speed and starts surprising us again with little tidbits....

Wayne

[Peashooter]

Re: Strega Questions: Can It Be True??

Peas:

Top fuel engines are putting out around 7000 - 8000 HP, according to some of the drivers, crews, and commentators. Those are the figures that I've heard repeated over and over. No one has ever dyno'd a top fuel engine. These are calculated guestimates.

The rpm range hasn't changed much: still 8000 - 9000.

The big problem: they only last 5 seconds. Sometimes less. They start eating parts very quick when all the parameters are are not perfect.

These engines make sooooo much power because of the amount of fuel and air they run through them (nitro and a supercharger). They run a good deal more fuel through them than the engine can burn. Helps for cooling.

Hope this helps.
Tommy

So Tommy, if you took that technology applied to a V-12 block with more cubes and lower RPMs, wouldn't it be feasible to achieve maybe 2/3 the power of a hand-grenade, top-fueler? Ballistic blanket, optional! That's 4-6,000 hp. The Bear and Dreadnought are in the 4-4,500 hp range. Put this power in a full-race Mustang airframe and one might have something. Might even hold off Renegade! Wouldn't be cheap, that's for sure -- reduction gearing, prop, etc. "Hello, Mr. Rousch?"

Fun to ponder. Queue Pink Floyd's "Money"!

[Ron101502]

Re: Strega Questions: Can It Be True??

Remember the problems the Pond racer had with the corrosive nature of methanol? And nitro needs to be cut with methanol to some extent. Other problems with pure methanol is that it doesn't have as much energy as gasoline, BUT you can burn lots more of it and compress it a lot higher than gas, allowing more boost and more HP. Nitro makes it even more problematic, as stochiometric fuel/air ration for gas is 14.7:1, methanol about 7:1, and nitro about 2:1, although they run closer to 1:1 for cooling. An engines limit to how much fuel they can burn is how much air they can pump. Rasing boost to where induction temps go above 115 degrees F doesn't gain any more air volume (the reason the nitro cars didn't lose much by going from 90 to 85% nitro is because the additional methanol served as an intercooler so the blower could be spun faster, and even more fuel could be burned more than off-setting the lower energy content of the fuel. This was predicted by Don Garlits and many teams were already experimenting with it early in the season. Next year, with blower overdrive limited to 1.5, the cars will slow down). So first of all aircraft fuel pumps would have to be modified to flow 80 gpm for every 500 cubic inches of displacement, or over 240 gpm for a Merlin and 500 gpm for a 3350, and fuel capacity would have to go up by a factor of 10 at least, which even if the volume were available it would weigh a lot. Then you would have to replace the mags with 44 amp units. And you can't start a nitro engine on nitro, you would need some sort of gas injection to start the engine on. And remember, a nitro engine idles at around 2700 rpm so gear changes are necessary. And how much horsepower can a prop use? It can only take so much pitch and rpm before it starts loseing thrust. It seems to me there would be an optimum pitch/rpm combination for a prop to make maximum thrust, and any horsepower in excess of the amount it takes to turn the prop in that configuration would be useless. And as I pointed out in the past, these are really torque engines and Rare Bear already makes about 7000 ftlbs of torque, the SAME as a top fueler. I bet (just guessing) that no prop can make good use of more than 5000hp anyway, and that figure certainly can be attained with gas and NOX with a lot less hassle. Big problem is holding the motors together.

Just some thoughts from yet another "airmchair expert".

[King]

Re: Strega Questions: Can It Be True??

Rousch, as I understand it, makes most of the consumables for a Merlin engine.

The roller rockers have not been very successful as of yet (again as I understand it). The Merlin fingers over rollers are generally the way to go for most of the operators.

Today I learned how to run the rack (remove, inspect and adjust the cam and rocker arm assemblies) on a Merlin and also assisted in changing out the valve springs. The Merlin is a pretty high tech engine considering being how old they really are.

[matt]

Re: Strega Questions: Can It Be True??

good point about the props not being able to absorb more than 5000 hp, as i understand it (as always i could be wrong) the current unlimited props are nearing the end of range of their efficiency, look closely at sub and supersonic props (i.e. xf-84h, f-88, etc.) and have hartzell make a (very expensive) set of these props, i think we'd see a great improvement in the top end performance of these planes.

worth a look anyway.

[Peashooter]

Re: Strega Questions: Can It Be True??

Great points Ron. Thanks!

[AAFO_WSagar]

Re: Strega Questions: Can It Be True??

The Merlin fingers over rollers are generally the way to go for most of the operators.

I'll have a double order of Merlin fingers and curly fries.... (sorry could't resist ) Man King, that's gotta be fun stuff and you're getting paid for this to boot ey!!

It is amazing piece of engine technology (I've not seen a lot of it in detail but can tell from drawings) considering the time isn't it... I still can get almost sea sick watching those cutaway radial jobbies.. There's a 4360 cutaway out at Evergreen what a mass of "monkey motion" that is!

It sort of makes you wonder, knowing what they do today about metals and all, having the computer aided design, if a firm was given unlimited funds to come up with the best piston airplane engine of the same sizes as the old ones, what would they achieve?? Would it be more for less weight and mass?? Or could they achieve even what they old timers came up with using slide rulers and man run machines??

Wayne