Ozzy27 F3 Race bike

[TonyB]

Back to the bike.... its an awesome idea Ozzy and I take my hat off to you for actually DOING it rather than just thinking about it.

You mentioned that the counterbalancing piston is draining about 8.5hp. That leads me to some questions (which will be asked in very non technical terms):
1) on an inline 4 crankshaft, is each piston/rod and crank throw self balancing, or do they work in pairs, with 1 and 2 balancing each other, and 3 and 4 balancing each other?
2) if they are self balancing, is it possible to rebuild the crank so that it just runs straight through- i.e you remove the piston/rod and throw?

I'm picking that if it is possible, it will be bloody expensive...

[glice]

This is a really cool idea. If I was going to race f3 this looks like the bike to go for.
How hard would it be to convert them back to a 600? then you could keep the same bike and step up to f2?

[Mental Trousers]

Well done Chris - the bike sounds awesome and goes well. It definitely looks the most affordable route to a competitive F3 bike - hopefully this innovation leads to a revival of F3 with a bunch of decent, affordable, interesting bikes out there going at it it - as the class was originally intended.

Exactly. This sort of crazy stuff gets me hard. Bring back the innovators so it isn't cheque book racing.

... stuff that sounded like shaun wrote it ...

You've been hanging around that Shaun Harris guy too long mate. But that's not necessarily a bad thing.

Well done mate. It sure sounds like it's a more cost effective route than getting an SV cos pulling bits out of a bike is usually much cheaper than throwing new bits at one!!

It means that someone can run their bike as a 450 in their 1st season then move through to the 600's on the same bike if they like. It could mean the cost of transitioning from F3 to F2 is seriously lower for people who take this route.

3 thumbs up (the middle one is usually not for guys but this sort of project is the exception!!!!)

[Shaun]

ive still got 2x K5 GSXR 600 race bikes, might just have to join ya Chris

[Mental Trousers]

ive still got 2x K5 GSXR 600 race bikes, might just have to join ya Chris

Farken F3 burglars ....

[Shaun]

Farken F3 burglars ....

I just mean to build and sell mine

[scracha]

You guys are on about it being a "cheap way into racing" and the usual "chequebook racer" waffle. I'm sure I heard similar arguments when SV's were first entered in the class....now look at the money that's spent on them. As much as we're proclaiming the virtues of being able to grab cheap not so competitive ex F2 bikes, it's a certainty that a chequebook racer will get a BRAND NEW 600, get it down to 450 and then spend about 25 grand on it.

The 450 is a corker of a bike and a wonderful feat of engineering but if anything it's gonna increase racing costs to similar levels to F2 (more power = more tyres for starters).

Ozzy..still wondering if a trumpy 900 could be cut down to 2 cylinders and a similar trick employed

[Mental Trousers]

Checkbooks always get involved in the end. Especially if a class is tightly restricted by rules. Then everyone is spending big dollars to make sure they're not disadvantaged by maximizing what is allowable.

Innovating is always a gamble. Get money involved and it's about reducing the odds for the best return.

[Ocean1]

Back to the bike.... its an awesome idea Ozzy and I take my hat off to you for actually DOING it rather than just thinking about it.

You mentioned that the counterbalancing piston is draining about 8.5hp. That leads me to some questions (which will be asked in very non technical terms):
1) on an inline 4 crankshaft, is each piston/rod and crank throw self balancing, or do they work in pairs, with 1 and 2 balancing each other, and 3 and 4 balancing each other?
2) if they are self balancing, is it possible to rebuild the crank so that it just runs straight through- i.e you remove the piston/rod and throw?

I'm picking that if it is possible, it will be bloody expensive...

Was wondering that myself.

When ballancing a crank you clamp weights to the journal, not the full mass of the rod/piston but a corrected mass calculated to have the same effect.

So why couldn't you do the same here? Less friction, slightly less rotational innertia... can't see it affecting ballance vertical moments, and I don't think it'd affect rocking moments...

Cool idea btw. As a matter of interest which is the dead cyl?

[Mental Trousers]

Leaving the piston and rod in place means you don't have to do anything with the cranckshaft. It's heaps cheaper (which was one of his aims I think)

However, if you wanted to lower the amount of horsepower lost to the dummy cylinder you could replace the piston with something that weighs exactly the same but allows air to pass through it to minimize pumping loses and uses rollers to lower friction loses (ie it doesn't need rings because there's no need to seal the cylinder).

[cowpoos]

However, if you wanted to lower the amount of horsepower lost to the dummy cylinder you could replace the piston with something that weighs exactly the same but allows air to pass through it to minimize pumping loses and uses rollers to lower friction loses (ie it doesn't need rings because there's no need to seal the cylinder).

There is a need to seal the cylinder...your crankcase would no longer be pressurised...and you would lose oil aswell...would be messy!

[Mental Trousers]

There is a need to seal the cylinder...your crankcase would no longer be pressurised...and you would lose oil aswell...would be messy!

Not if you seal the entire cylinder off. Bloke the intake and exhaust ports and sparkplug hole and there's no reason to have a piston that seals the cylinder anymore.

[Ocean1]

Leaving the piston and rod in place means you don't have to do anything with the cranckshaft. It's heaps cheaper (which was one of his aims I think)

However, if you wanted to lower the amount of horsepower lost to the dummy cylinder you could replace the piston with something that weighs exactly the same but allows air to pass through it to minimize pumping loses and uses rollers to lower friction loses (ie it doesn't need rings because there's no need to seal the cylinder).

Yup, removing the crank add a bit to costs, not much though.

And with that in mind, to take your idea a tad further... why not just leave the valves in place, (minus the followers?) remove the rings and make a hole in the piston?

Edit: because you'd pump too much oil up top?

There is a need to seal the cylinder...your crankcase would no longer be pressurised...and you would lose oil aswell...would be messy!

... unless you replace the valves?

[k14]

How many rings do these have? You could just go to 1 or 2 rings on the piston, reduce friction slightly for minimal effort??

[Mental Trousers]

And with that in mind, to take your idea a tad further... why not just leave the valves in place, (minus the followers?) remove the rings and make a hole in the piston?

Somewhere above Ozzy said that if the valves are removed the bike is within the rules. Can't think of how you leave the valves to seal off the cylinder unless you alter the cam shaft so they're never lifted, but that means altering a cam shaft.

How many rings do these have? You could just go to 1 or 2 rings on the piston, reduce friction slightly for minimal effort??

Yep. To reduce friction loses to an absolute minimum you'd want to get rid of the rings all together though.