10k rpm engines

[Darkclaw13]

Ok, first let me be perfectly clear here, this is a question that is purely to satisfy my curiousity. So, assuming that money is no option, what would it take to create a roughly 350 cubic inch V8 that could spin to 10K rpm reliably?

[camcojb]

Ok, first let me be perfectly clear here, this is a question that is purely to satisfy my curiousity. So, assuming that money is no option, what would it take to create a roughly 350 cubic inch V8 that could spin to 10K rpm reliably?

A friend of mine had one. A Pro Stock truck engine that someone sold off when the class was ended. (940 HP at 9700 rpm or so, dyno STARTED the pulls at 6000 rpms).

I think he paid $17K or so for it from split Dominators to pan. Much less than building one new from scratch.

Then again, I guess it would depend on if you just wanted it to spin to 10000 rpms or actually be making power up there. And the maintenance is EXTREME to keep the engine running right.

Jody

[Blown353]

The engine Jody is talking about was one of my friend's old engines, and one of his weaker ones at that (his last variants were making right around 1100hp out of 342 cubic inches.)

You can spin 10K rpm, but it takes expensive lightweight components and valvesprings don't live long (i.e. relashing EVERY run and replacing valve springs every 3-4 passes.)

Let's put it this way; near the end of the Pro-Stock truck series, my friend was paying about $10,000 for 16 Beryllium pushrods. That's right, 10 grand for PUSHRODS. They were worth almost 25 hp up top because of the low mass and stiffness, and as close as the class was it was worth it for him. Everything has to be as light and as stiff as possible to take that kind of RPM's. I remember him "finding" double-digit HP up top by gusseting and welding the shaft mount rocker pedestals together to make everything stiffer.

I'm sure you could make the valvesprings live longer with a less radical cam, but you NEED a radical cam to feed the engine at 10,000 rpm as it's moving a LOT of air very very quickly at that speed.

As far as new cost on the engines, you're looking at over $50K to do it right and make power. Everything has to be very light, the heads have to flow a ton, valvesprings are very high pressure and very high dollar, lifters are a couple grand a set to take the RPM's and spring pressures, expensive pushrods, etc. If I remember correctly the cylinder heads he was running cost between 17K-20K a pair depending on the casting and who did the porting. You need killer heads to flow enough to make the HP at high RPM; without the heads, it won't "rev up".

Oh, and did I mention frequent teardowns? As you increase RPM, you exponentially increase the loads on the internal engine components (think back to physics, KE = 1/2 mv^2); as the rod and piston velocity increases, the energy and loads on the rotating assembly increase as a square of the velocity. Thus, the higher you spin the engine you exponentially increase the stress on pistons, rods, bearings, crank, etc. Since the piston speed is determined mostly be RPM (rod length/stroke comes into play, but for a specific combo it's dictated by RPM) the only way to cut down on the energy is to run super light components, and those cost BIG bucks (think back to the pushrods I mentioned.)

It does sound wild though. As Jody said, nothing like hearing a 6000-10,600 rpm dyno pull. You swear that all the rods are going to jump out of the block, but somehow they don't.

And now that's he's building Pro-Stock motors, it's even wilder hearing 500 cubic inches spinning up to 9800. Yee-haw!

Troy

[indyjps]

ive got a set of the nascar pontiac small chevy heads that will get you to 9000 rpm easy if you are serious about building one of these, ill pull out the flow bench data on them.

[Darkclaw13]

No, I'm not really serious about building one of these engines. I was just reading about an Ultima that has an engine like this and I was curious about how hard it would be to accomplish something similar.
If you guys are interested here is the website-Ultima

[camcojb]

That is not a 10000 rpm engine, they just said they gave it a 10000 rpm balance job. With the power it has there's no reason to run anywhere near that rpm.

Cool car!

Jody

[Darkclaw13]

yeah I know its not a 10,000 rpm engine but it just got me thinking about what it would take to make one.

[camcojb]

yeah I know its not a 10,000 rpm engine but it just got me thinking about what it would take to make one.

Jody