Race engine build?

[shogun32]

Ti valves are 40 percent lighter, and they alone would ad 1500+ rpm to the rev range.

really? What about spring harmonics and float? Not to mention metallurgy failure? I also rather doubt the crank is balanced so well that you wouldn't get problematic second and third-order vibrations.

Max torque 8200 rpm

Yikes. I think you'd want peak'ish (90% of max) torque starting around 4 grand and 'flat' till 6.5, maybe even 7. Have you figured out lift, duration and phasing of the cams that could pull something like that off? And the intake volume, shape, and runner length?

I expect Direct Injection would have to be scrapped. Have you actually calculated the FPM (feet per minute) of the 92.7mm stroke at over 8000 RPM? Anything much past 5000 and you're stepping into exotic territory. Unless you're going to rebuild the engine every dozen runs... Destroke down to 86 or 87 and you could probably get away with 9000RPM for a while.

You're kidding yourself with that budget. There is a far smarter answer to this silly idea. Buy and retrofit a COPO motor into the 'stang.

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[gregsdart]

really? What about spring harmonics and float? Not to mention metallurgy failure? I also rather doubt the crank is balanced so well that you wouldn't get problematic second and third-order vibrations.


Yikes. I think you'd want peak'ish (90% of max) torque starting around 4 grand and 'flat' till 6.5, maybe even 7. Have you figured out lift, duration and phasing of the cams that could pull something like that off? And the intake volume, shape, and runner length?

I expect Direct Injection would have to be scrapped. Have you actually calculated the FPM (feet per minute) of the 92.7mm stroke at over 8000 RPM? Anything much past 5000 and you're stepping into exotic territory. Unless you're going to rebuild the engine every dozen runs... Destroke down to 86 or 87 and you could probably get away with 9000RPM for a while.

You're kidding yourself with that budget. There is a far smarter answer to this silly idea. Buy and retrofit a COPO motor into the 'stang.

1 assembly in an all out hi rpm deal would be professionally balanced. No big deal. Look at the stats for some of the legal drag class motors like SSAH Hemis. 3.780 stroke . 10,000 rpm! and that with huge valves, no less.
2 For a purely drag application, there is no sense in planning for anything much below the stall speed you can run. So torque can move way up, increasing hp because of it. Example; if I built a budget 5.0, factory parts I would have to reuse in the build would probably limit me to 8500 rpm max. With that as a peak rpm, my torque peak could be anywhere up to 7,000 because the fastest way down the track is a VERY narrow rpm range to run at a dragstrip. Remember, a custom converter will flash to that 7,000 rpm target, hopefully about 7500. That leaves a 1,000 rpm working window for the motor going down the track. Now you can take the average power from 7500 to 8500, and that is the average power being provided to move the car. Even with some percentage of loss due to slippage in the converter, the average power is still much better than trying to run from 5,000 to 8500! As for manifolds, the Ford racing intake would be a good budget piece. I can't afford $3,000 sheetmetal intakes! But that Ford intake is a hi rpm piece, just right for a budget build. Ford has done all the design work for me! Never reinvent the wheel! As for moveing the torque, custom cams, ground with lobes of longer duration but less intensity than most race cams, ought to allow some pretty hi rpm limits with nothing more than better valve springs. These motors are a dream compared to what I work with on my 528 wedge motor. Imagine what it takes to control a half inch thick SOLID STEEL ten inch long pushrod, a roller lifter almost an inch in diameter and three inches long, then a rocker arm, and don't forget the 5.2 inch long 2.3 inch diameter steel valve! I have to run 340 lbs of seat pressure and 900 lbs of load at max lift to keep that thing happy at 7600 to 7800 rpm! When all you have to control is a tiny little valve, spring, and retainer, plus half the rocker weight, its a piece of cake by comparison.
I think the main thing you missed is this is all speculation. One part of it was what could I do if I were wealthy, and the other part was what could I do on a budget. Two different worlds. But I see this Coyote motor as having real potential as a cheap source of normally aspirated horsepower for special situations some day, when there are a ton of them in boneyards.

 

[BrianGT2015]

not so deep here. My limit would be maybe 18000? Take away the enitial cost of a core engine and that really cuts into what i could do. Now hand a pro 40 gs and a good core, and you would see a SERIOUS build, with stuff like sheetmetal intake manifold, stainless long tube custom headers, heads fully ported for the intended use and cams plus valvetrain that would run in the stratusphere! I have no clue what max rpm might be with the best heads and valvetrain, but speculate it could be as hi as 11,000 rpm or more! If i can spin a motor designed in 1957 to over 7600 to 8000, imagine what a pro could do starting with an engine that has a factory redline (gt350 motor) of 8200!

11,000 RPM I am skeptical but intrigued. Probably not a good street motor by any means.

 

[gregsdart]

11,000 RPM I am skeptical but intrigued. Probably not a good street motor by any means.

Nope Not a street motor, or even close. I was speculating on what was possible for what a dedicated drag motor might do. There are a lot of assumptions in my posts. Fun though

 

[Matt-23]

I'm a qualified motorcycle mechanic, sticking my head under the bonnet and changing timing gears and oil pump gears of a 17 Mustang surprised me how similar each side bank was to a 1000cc motorcycle motor. I think you could achieve your 10,000rpm limit by trying to limit valve float and strengthen the long timing chains.
Mind you I have never worked on a V8 motorcycle and the screamers that reach 18,000 / 21,000 rpm are gear driven valve trains.
I'm not sure if the size of the piston moving up and down the cylinder may over stretch the con-rod but I'm very keen to see how this all plays out.

 

[gregsdart]

I'm a qualified motorcycle mechanic, sticking my head under the bonnet and changing timing gears and oil pump gears of a 17 Mustang surprised me how similar each side bank was to a 1000cc motorcycle motor. I think you could achieve your 10,000rpm limit by trying to limit valve float and strengthen the long timing chains.
Mind you I have never worked on a V8 motorcycle and the screamers that reach 18,000 / 21,000 rpm are gear driven valve trains.
I'm not sure if the size of the piston moving up and down the cylinder may over stretch the con-rod but I'm very keen to see how this all plays out.

One thing occured to me about pistons. Cast hyper pistons are running up to 7500 rpm in stock 5.0 motors. I would assume Ford built in an aproximate 25 percent strength safety margin in those pistons. By going to forged pistons with better, stronger piston pins than say the gt350 motors, that should allow some fairly high rpm limits. Same with conecting rods. Rods in the racing world can be made much stronger than the best Ford has right now. It is just a matter of $$$$! There are V8 rod sets out there with killer strength but cost is over 1500 a set. A bit rich for me. Piston material and design i know little about but a call to one of the piston makers would give us a lot of info.

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