revtothelimit - motorbike forum

Yorick wrote: Wed Jul 14, 2021 8:33 pm
Your ignorance and perseverance is staggering.

I was just thinking the same.

I'll just leave it there.

Mr. Dazzle wrote: Wed Jul 14, 2021 8:35 pm

Yorick wrote: Wed Jul 14, 2021 8:33 pm
Your ignorance and perseverance is staggering.

I was just thinking the same.

I'll just leave it there.

I built and raced petrol 2-stroke engines.
You haven't a clue how they work.

Stick to Google.

Designers of two stroke bike engines try to maximise crankcase compression, to maximise “transfer” into the cylinder. Forced induction by turbocharger or supercharger will help that a lot, but as Yorbles says, you can take the crankcase out of the induction path and blow air or mixture into the cylinder.

Fromage wrote:and it won't increase compression in the combustion chamber.

It can.

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.

Been thinking.
The brief peiod that the piston isn't covering both the intake and exhaust ports, you would be shooting the extra boost straight out the exhaust . Too much pressure will fuck things up.

That's why I said a good Spanny will be needed. But they can't work miracles.
They themselves are simple turbochargers in reverse.

They've only done it in last few years on a Skidoo.

inewham wrote: Wed Jul 14, 2021 9:07 pm You're all overthinking this someone has done it because they can, just because it sounds good. A 50cc engine probably doesn't have enough exhaust pressure to get the turbo spinning properly. It's a just because they can

The exhaust needs to be an expansion chamber to handle the extra pressure.

There's a hole on my bucket delilah

Yorick wrote: Wed Jul 14, 2021 8:57 pm
Been thinking.
The brief peiod that the piston isn't covering both the intake and exhaust ports, you would be shooting the extra boost straight out the exhaust . Too much pressure will fuck things up.

It doesn’t all go out the exhaust. Port timings and sizes (and everything else) are designed to work with the boosted intake.

Let me be more specific, how would turbo charging a FS1E engine work?

And I know about turbocharged two stroke diesels, I see them every day at work, I also know about supercharged two strokes like DKWs and Puchs.

Le_Fromage_Grande wrote: Wed Jul 14, 2021 11:14 pm Let me be more specific, how would turbo charging a FS1E engine work?

Le_Fromage_Grande wrote: Wed Jul 14, 2021 11:14 pm Let me be more specific, how would turbo charging a FS1E engine work?

Les well than increasing its capacity to 85 cc, but if I really wanted to try forced induction, I’d go for supercharging and I’d remove the disc valve.

JackyJoll wrote: Wed Jul 14, 2021 11:46 pm

Le_Fromage_Grande wrote: Wed Jul 14, 2021 11:14 pm Let me be more specific, how would turbo charging a FS1E engine work?

Les well than increasing its capacity to 85 cc, but if I really wanted to try forced induction, I’d go for supercharging and I’d remove the disc valve.

Super charged two strokes don't put the mixture through the crankcase, they have a separate charging cylinder that does the same job as sucking the mixture into the crankcase.

Le_Fromage_Grande wrote: Thu Jul 15, 2021 6:54 am

JackyJoll wrote: Wed Jul 14, 2021 11:46 pm

Le_Fromage_Grande wrote: Wed Jul 14, 2021 11:14 pm Let me be more specific, how would turbo charging a FS1E engine work?

Les well than increasing its capacity to 85 cc, but if I really wanted to try forced induction, I’d go for supercharging and I’d remove the disc valve.

Super charged two strokes don't put the mixture through the crankcase, they have a separate charging cylinder that does the same job as sucking the mixture into the crankcase.

You asked about an FS1E.

There have been many and very varied configurations of two stroke engines designed to induct more charge than you get from just crankcase compression.

Yorick wrote: Wed Jul 14, 2021 8:21 pm

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.

Do you know how a 2 stroke petrol engine works?

Yes.

David wrote: Thu Jul 15, 2021 7:47 am

Yorick wrote: Wed Jul 14, 2021 8:21 pm

Do you know how a 2 stroke petrol engine works?

Yes.

Should have been a poll.

David wrote: Thu Jul 15, 2021 7:47 am

Yorick wrote: Wed Jul 14, 2021 8:21 pm

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.

Do you know how a 2 stroke petrol engine works?

Yes.

Right wrist downwards
Ringadingding noise louder
Right wrist upwards
Front wheel down again

?

Le_Fromage_Grande wrote: Wed Jul 14, 2021 11:14 pm Let me be more specific, how would turbo charging a FS1E engine work?

I've just remembered this video which did the rounds a while back. Turbocharged Vespa with 40bhp!

I refer m'learned friend back to his original Q though. Why?

I feel for the guy dyno'ing it...

I know fuck all about turbo 2Ts and 2T diesels, yet, here I am, fitting in...

Taipan wrote: Thu Jul 15, 2021 11:25 am I know fuck all about turbo 2Ts and 2T diesels, yet, here I am, fitting in...

Yeah. We need some eye candy. Just sit over there luv

https://www.ebay.co.uk/itm/274868224525 ... SwHj9g8AYI