"trackday"


I know a man that has a few more. The vicar that found them all and is now selling them.weeksy wrote: Thu Jul 08, 2021 6:34 am One of the lads on PB forum bought 2... yes 2... Petronas FP1s..... this had 0 miles on the clocks at the start of the session... brand spanking new, his first thought..
"trackday"
![]()
And would need a spannie more than normal.Le_Fromage_Grande wrote: Wed Jul 14, 2021 4:49 pm I'm trying to work out what turbocharging a two stroke would do, pressurise the crankcase is about the best I can come up with.
Its like running it somewhere with higher atmospheric pressure innit? Think about what would happen if you ran one somewhere there was very low atmospheric pressure (like up a mountain) and what would happen, that might be easier to visualise.Le_Fromage_Grande wrote: Wed Jul 14, 2021 4:49 pm I'm trying to work out what turbocharging a two stroke would do, pressurise the crankcase is about the best I can come up with.
That's the case with a 4 stroke or 2 stroke diesel, but with a conventional 2 stroke the fuel, air, oil mixture is sucked into the crankcase by the piston going up, then pushed/sucked into the combustion chamber by the piston coming down, if you pressurise the crankcase it will make it harder for the piston to come down, and it won't increase compression in the combustion chamber.Mr. Dazzle wrote: Wed Jul 14, 2021 6:51 pmIts like running it somewhere with higher atmospheric pressure innit? Think about what would happen if you ran one somewhere there was very low atmospheric pressure (like up a mountain) and what would happen, that might be easier to visualise.Le_Fromage_Grande wrote: Wed Jul 14, 2021 4:49 pm I'm trying to work out what turbocharging a two stroke would do, pressurise the crankcase is about the best I can come up with.
It will, you just have to hope/ensure that the extra bang you get from shoving more fuel outweighs the above. It's not too dissimilar with a 'conventional' 4 stroke turbo, you chuck more air in and hence make the engine work hard pushing it all about and compressing it. You just need to be sure the cons are outweighed by the pros.Le_Fromage_Grande wrote: Wed Jul 14, 2021 7:20 pm if you pressurise the crankcase it will make it harder for the piston to come down, and it won't increase compression in the combustion chamber.
Don't contradict him. He's a self confessed expert in 2 strokes.Le_Fromage_Grande wrote: Wed Jul 14, 2021 7:20 pmThat's the case with a 4 stroke or 2 stroke diesel, but with a conventional 2 stroke the fuel, air, oil mixture is sucked into the crankcase by the piston going up, then pushed/sucked into the combustion chamber by the piston coming down, if you pressurise the crankcase it will make it harder for the piston to come down, and it won't increase compression in the combustion chamber.Mr. Dazzle wrote: Wed Jul 14, 2021 6:51 pmIts like running it somewhere with higher atmospheric pressure innit? Think about what would happen if you ran one somewhere there was very low atmospheric pressure (like up a mountain) and what would happen, that might be easier to visualise.Le_Fromage_Grande wrote: Wed Jul 14, 2021 4:49 pm I'm trying to work out what turbocharging a two stroke would do, pressurise the crankcase is about the best I can come up with.
Indeed - turbo 2 strokes are really really common. But generally they don't have pressurised crankcases, they have 4 stroke-esque cranks and 'open' cases. In that situation you must turbo/supercharge 'cause there's nothing else to 'push' the air in.v8-powered wrote: Wed Jul 14, 2021 8:08 pm Fair few trains are powered by turbocharged 2-stroke diesel engines.....
They are nothing like petrol 2 stroke engines.v8-powered wrote: Wed Jul 14, 2021 8:08 pm Fair few trains are powered by turbocharged 2-stroke diesel engines.....
FFS. Thats diesel engines. Nowt like a petrol 2 stroke engine.Mr. Dazzle wrote: Wed Jul 14, 2021 8:11 pmIndeed - turbo 2 strokes are really really common. But generally they don't have pressurised crankcases, they have 4 stroke-esque cranks and 'open' cases. In that situation you must turbo/supercharge 'cause there's nothing else to 'push' the air in.v8-powered wrote: Wed Jul 14, 2021 8:08 pm Fair few trains are powered by turbocharged 2-stroke diesel engines.....
I'm guessing cheesy is asking why'd you'd bother turboing a bike style 2 stroke with transfer ports but as above the idea was thought up years and years ago. You can now buy an engine like that off the shelf.
Do you know how a 2 stroke petrol engine works?David wrote: Wed Jul 14, 2021 8:19 pm Diesel engines are a lot like petrol except for the ignition system and consequent heavier engineering....most diesel engines can be petrolised, doesnt work well the other way round.
Did you actually read any of the links?Yorick wrote: Wed Jul 14, 2021 8:15 pmFFS. Thats diesel engines. Nowt like a petrol 2 stroke engine.Mr. Dazzle wrote: Wed Jul 14, 2021 8:11 pmIndeed - turbo 2 strokes are really really common. But generally they don't have pressurised crankcases, they have 4 stroke-esque cranks and 'open' cases. In that situation you must turbo/supercharge 'cause there's nothing else to 'push' the air in.v8-powered wrote: Wed Jul 14, 2021 8:08 pm Fair few trains are powered by turbocharged 2-stroke diesel engines.....
I'm guessing cheesy is asking why'd you'd bother turboing a bike style 2 stroke with transfer ports but as above the idea was thought up years and years ago. You can now buy an engine like that off the shelf.
But carry on.
Yes. They contradict all you said.Mr. Dazzle wrote: Wed Jul 14, 2021 8:24 pmDid you actually read any of the links?Yorick wrote: Wed Jul 14, 2021 8:15 pmFFS. Thats diesel engines. Nowt like a petrol 2 stroke engine.Mr. Dazzle wrote: Wed Jul 14, 2021 8:11 pm
Indeed - turbo 2 strokes are really really common. But generally they don't have pressurised crankcases, they have 4 stroke-esque cranks and 'open' cases. In that situation you must turbo/supercharge 'cause there's nothing else to 'push' the air in.
I'm guessing cheesy is asking why'd you'd bother turboing a bike style 2 stroke with transfer ports but as above the idea was thought up years and years ago. You can now buy an engine like that off the shelf.
But carry on.
Your ignorance and perseverance is staggering.the world’s first factory-built 2-stroke turbo engine.