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10,000 RPM V8 for the street?


zeitgeist57

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With everyone talking about maximum horsepower, I'm curious as to what the upper limits are currently with engine RPM's and the aftermarket technology available to support 10,000rpms.

 

Why would someone want to do this? Sounds cool, and a well-designed engine can continue to build power without having to shift. With underdrive pulleys, you could still save the accessory drive units also. Clutch and transaxle RPM limits could be a problem...

 

A quick Google search showed LSx capability...what about small-block Chevy's? 302/351 Fords? 4.6L-mod Fords?

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Its possible, just not efficient. Somewhere, I've seen a claim that a LSx can hit 10000rpm with just these alone

 

Their own sites says 14850rpm, but not what kind of motor.

 

Increased Engine Power - The comparative efficiencies of the spherical rotary valve combustion engine have enabled engine speeds of 14,850 RPMs.
http://www.coatesengine.com/csrv.html

 

Edit: They did it with a V8 http://www.ls1-australia.com/forum/viewtopic.php?f=21&t=320&start=0

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my guess would be that the biggest problem on an american v8 would be the valve train. what's the fastest a pushrod motor has turned?

 

GM Racing spins theirs under 8k. there is no reason for a V8 to spin that fast unless your into the redneck nascar stuff. those engines are push rod V8's and spin over 9k.

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you would have to go with a ford mod motor or other OHC engine. there is no way your gonna be able to spin a pushrod engine at those RPMs reliably. NASCAR engines get rebuilt after every race for a reason. either way though, you'll definitely see an increased wear rate on all of the engines bearings.

 

also, you'll have to go with a dogring transmission. modern synchro transmissions can't withstand the combination of RPM and torque of a large capacity V8 spinning that fast(hence why you don't hear about large capacity 10,000RPM V8 engines in road racing).

Its possible, just not efficient. Somewhere, I've seen a claim that a LSx can hit 10000rpm with just these alone

 

Their own sites says 14850rpm, but not what kind of motor.

 

http://www.coatesengine.com/csrv.html

 

Edit: They did it with a V8 http://www.ls1-australia.com/forum/viewtopic.php?f=21&t=320&start=0

IIRC, that valve train has sealing issues.

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you would have to go with a ford mod motor or other OHC engine. there is no way your gonna be able to spin a pushrod engine at those RPMs reliably. NASCAR engines get rebuilt after every race for a reason. either way though, you'll definitely see an increased wear rate on all of the engines bearings.

 

And how many of them blow up each race? Could your car's engine spin 8000rpm for 500 miles? Would you consider your engine reliable?

 

also, you'll have to go with a dogring transmission. modern synchro transmissions can't withstand the combination of RPM and torque of a large capacity V8 spinning that fast(hence why you don't hear about large capacity 10,000RPM V8 engines in road racing).

 

WTF are you talking about? How much torque do you think a Nascar motor makes at 9000rpm compared to 5000rpm? A "modern" synchromesh transmission can handle 10,000 rpm just fine. Ugh!

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Some transmissions don't like to shift above a certain RPM

That's why you don't put 10,000rpm motors into a wheel horse. Synchros are perfectly capable of handling 10k rpm- just go to youtube, search 10000rpm and tell me people can't shift.

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That's why you don't put 10,000rpm motors into a wheel horse. Synchros are perfectly capable of handling 10k rpm- just go to youtube, search 10000rpm and tell me people can't shift.

 

Yeah, but the stock engagement teeth isnt exactly designed for high RPM shifts. Grind em till you find em.

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Yeah, but the stock engagement teeth isnt exactly designed for high RPM shifts. Grind em till you find em.

 

neither are the stock valvetrain or clutch. If 1950s transmissions could handle 7000+ rpm, I'm sure we can get you a nice "modern" synchromesh tranny that will handle your piddly-ass 500 lb-ft and 10k rpm;)

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I've heard of old-school small-cube small-block Fords turning 10k in drag applications. 260s and 289s, and de-stroked versions of those motors. And there are bunches of land-speed cars turning massive RPMs due to tire size limits (well, availability rather than size limit, really.)

And of course there's Formula 1, with motors that can touch on 20k, but those are not EXACTLY a street motor, being constructed of pure money...

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neither are the stock valvetrain or clutch. If 1950s transmissions could handle 7000+ rpm, I'm sure we can get you a nice "modern" synchromesh tranny that will handle your piddly-ass 500 lb-ft and 10k rpm;)

 

Yeah, that was kind of my point that you would have to change or modify it. It depends on the trans but I know that DSM's "require" it at around 10k rpm, and it is a modern trans. So a "1950s" v8 trans, which is designed to be mated to a motor that in factory form spins almost half as fast as a DSM does, is more likely to require modification at a lower RPM.

 

I dont think anyone has attempted to rev an S4 trans high enough for it to be a problem, highest that I know of is 9k. 500tq @ 10k, ha i wish, more like 200

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My buddy has a DZ 302 that is .030 over, aluminum rod motor, gas ported pistons, 14:1 compression, aluminum heads, 950 carb, 3600# 68 Camaro, toploader 4 speed going 9.90's @ 135,136 shifting at 11,500... He puts valve springs every 2000 miles and drives it on the street...
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Ha, young'ins.

 

The cars winning classes in in the 60's and thereabouts were spinning V8's North of 10,000 rpms all day and night long, while leaving the line at the RPM range that most people set their rev limiters.

 

You will not find a better sound than a small cube SBC spinning 10k through a 4 speed on a country road.

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