Ever wanted to see what your valves are doing?

[steve_t]

OK, so it might not be your valves but the valves of a BMW S1000RR. Pretty amazing our bikes can rev so frickin high - and this is 'only' to 14k RPM



Oh, and when I was looking to see if I was reposting, I found this thread which is pretty frickin cool too if you haven't already seen it

http://www.kiwibiker.co.nz/forums/sh...-video-footage

[schrodingers cat]

That is cool! Interesting watching the valves rotate as well

[peasea]

That's pretty cool.

I saw a test bed for fuel systems in operation once with a pump and injectors off a supercharged, injected, alcohol burning big block Chevy going hard out. It fed into a perspex box and you would have been astounded at the volume of fuel that puppy ate. They talk in gallons per minute and even though a 1/4mile run might only take six seconds or thereabouts with a good alcohol deal (some are faster) that might equate to 18-20 gallons per run, or 90 litres, that's in 6secs-ish. (Rough figures, and nitromethane powered vehicles get through even more!)

[peasea]

That is cool! Interesting watching the valves rotate as well

And so they should, if they don't they can burn.
The tip of the valve (the end you can't see there) should be slightly convex to induce this rotation. From memory I think we ground the valve tips to 1.5 degrees.

[onearmedbandit]

That's pretty cool.

I saw a test bed for fuel systems in operation once with a pump and injectors off a supercharged, injected, alcohol burning big block Chevy going hard out. It fed into a perspex box and you would have been astounded at the volume of fuel that puppy ate. They talk in gallons per minute and even though a 1/4mile run might only take six seconds or thereabouts with a good alcohol deal (some are faster) that might equate to 18-20 gallons per run, or 90 litres, that's in 6secs-ish. (Rough figures, and nitromethane powered vehicles get through even more!)

Mighty impressive alright, but you also have to account for idling, staging and burn-out. But still that's gulping a heck load of fuel.

[peasea]

Mighty impressive alright, but you also have to account for idling, staging and burn-out. But still that's gulping a heck load of fuel.

Ahhh, burnouts.
Hard launches are cool too.
Our wee thing had a 0-60ft time of .9 something.

[peasea]

Check the slick distortion, not bad for a 355ci small block eh?

[onearmedbandit]

Very impressive. What pressure would you run on average in the back hoops?

[bogan]

Ever wanted to see what your valves are doing?

well I'm still wondering, cos I'm pretty sure my valves don't go that fast cool vid though

[Katman]

At 6000 RPM a piston is moving up and down 100 times per second.

I've been a mechanic for 30 years and it still blows me away that things can happen that fast.

[peasea]

Very impressive. What pressure would you run on average in the back hoops?

Shit, you got me there, I was the engine man. I think it might'a been 3.5 or 4 lbs, sfa.

[peasea]

At 6000 RPM a piston is moving up and down 100 times per second.

I've been a mechanic for 30 years and it still blows me away that things can happen that fast.

Actually, the crank goes round at 100 times per second, the pistons go up, then down, for that one revolution.
Not long into my engine building years I put together a single four-barrel small block Chev, 302ci, roller cam thing that went through the traps at 9,000rpm. 150 rps. That's where ring surface speed enters the equation.

[peasea]

well I'm still wondering, cos I'm pretty sure my valves don't go that fast cool vid though

What's your bikes red line?

[Katman]

Actually, the crank goes round at 100 times per second, the pistons go up, then down, for that one revolution.
Not long into my engine building years I put together a single four-barrel small block Chev, 302ci, roller cam thing that went through the traps at 9,000rpm. 150 rps. That's where ring surface speed enters the equation.

Yeah, but a crank spinning at 100 times per second isn't as mindblowing as a piston moving from stopped to warp speed to stopped and back to warp speed at 100 times per second.

[bogan]

What's your bikes red line?

bout 8k, has 66mm stroke though, which is bit longer than most high reving bikes I think, so higher piston speed. Which actually gives a max piston speed of about 27.6m/s which is just a fraction under 100kmhr. This sort of speed translates to oh fuck that hurt, when a piston flys through the head and smacks you on the elbow



fucking brutal