Why do SV's have engine braking?

Originally Posted by ophic

and the answer is... they don't. I found an article comparing IL4s and V-twins. Will post a link when i find it again. It says a TL1000 has approx the same engine braking effect as a similar sporty IL4. Not entirely sure i believe this though.

Couldn't someone with a mate with an IL4 do a practical comparison and put us out of our misery? (I would but I havn't got any mates. )

[ophic]

http://www.bayarearidersforum.com/fo...&postid=863287

scroll down for the scanned article

Hmmmm....seems we might have been trying to explain a phenomenon which doesn't actually exist!
Maybe people put the way the back wheel is more prone to locking up on downchanges with a v twin down to lots of engine braking.

Originally Posted by ophic

http://www.bayarearidersforum.com/forums/showthread.php?s=&postid=863287

scroll down for the scanned article

Thanks ophic. Very interesting

So to sum up, 'Engine braking results from 2 major causes: 1)Engine friction and 2) the pumping losses caused by tring to pull air past a carb(s) closed to idle position.'

The bike with the most engine braking - in that article - was the Yamaha R1 Interesting bit also, about rear wheel lock-up

Just noticed what bike the guy who posted the article rides. Where do I get one of them mods for my SV? I'd love a girlie ass on my SV

[ophic]

Originally Posted by Daz

I'd love a girlie ass on my SV

they can be hard to come by - and is definitely a mod that requires regular maintenance. Doesn't do much for performance either. Might affect engine braking too...

Originally Posted by ophic

they can be hard to come by - and is definitely a mod that requires regular maintenance. Doesn't do much for performance either. Might affect engine braking too...

Originally Posted by ophic

they can be hard to come by - and is definitely a mod that requires regular maintenance. Doesn't do much for performance either. Might affect engine braking too...

This is definatly a mod which requires a lot of consideration before applying. It may be aesthetically pleasing but can have horendous effects on performance and handling and will prove to be a continual drain on your pocket for years to come.

It is definetly to do with the valve timing. Higher revving engines are designed to produce more power by revving higher at the expense of lower down power. Higher revving (IL4 usually) have valve timings that overlap considerably. A lot of time both inlet and exhaust are open at the same time! Engines designed to produce power lower down the rev range irrespective of design will have far less valve 'overlap'. Hence your sucking against a closed space for most of the time and that slows you down better!
What do you think?

[ophic]

Originally Posted by skidmarx

It is definetly to do with the valve timing. Higher revving engines are designed to produce more power by revving higher at the expense of lower down power. Higher revving (IL4 usually) have valve timings that overlap considerably. A lot of time both inlet and exhaust are open at the same time! Engines designed to produce power lower down the rev range irrespective of design will have far less valve 'overlap'. Hence your sucking against a closed space for most of the time and that slows you down better!
What do you think?

sounds feasible. I always suspected it was due to engine design characteristic and not really anything to do with number of cylinders or configuration.

So what did I win then?