R300 roller barrell - what is it?
Discussion
i underastand that there is something called roller barrel on an R300. i have no idea what it is other than it seems to be desirable...
could someone tell me what it is?
is this one of those questions i'm going to be really embarrassed about asking one day, because it really is basic???
could someone tell me what it is?
is this one of those questions i'm going to be really embarrassed about asking one day, because it really is basic???
Not really a basic question because this system is not really found on other cars. The roller barrel throttle body to give it its full title is a very efficient design of throttle body.
Basically a standard K-Series engine has a single throttle body or plenum chamber to allow air into the engine. This is the long plastic or latterly metal chamber on one side of the engine and has a single throttle butterfly to allow air into the engine. This is great from a noise, economy and emissions point of view but slightly restrictive on power.
Conventional throttle bodies create one air inlet per cylinder with a butterfly to control the air flow into each.
The roller barrel throttle barrel is two barrels which fit inside one another with an equal sized hole in each. The barrels roll with the throttle action creating a gradually increading sized hole and at full throttle a totally clear passage of air into the engine. This means that there is no throttle butterlfly allowing a smooth uninterupted flow of air into the engine.
In short Roller barrels sound fantastic and make for a great engine!
Basically a standard K-Series engine has a single throttle body or plenum chamber to allow air into the engine. This is the long plastic or latterly metal chamber on one side of the engine and has a single throttle butterfly to allow air into the engine. This is great from a noise, economy and emissions point of view but slightly restrictive on power.
Conventional throttle bodies create one air inlet per cylinder with a butterfly to control the air flow into each.
The roller barrel throttle barrel is two barrels which fit inside one another with an equal sized hole in each. The barrels roll with the throttle action creating a gradually increading sized hole and at full throttle a totally clear passage of air into the engine. This means that there is no throttle butterlfly allowing a smooth uninterupted flow of air into the engine.
In short Roller barrels sound fantastic and make for a great engine!
Just an idea but if your after info on R300's try www.r300.net/ we are a friendly bunch
dino ferrana said:Roller throttles sound better because you can hear the induction more clearly; the plenum dampens the noise.
It is cheaper but also helps on emissions, noise and economy. The emissions is the reason that the CSR200 has a plenum (specially cast for Caterham) rather than throttle bodies. This is so that the engine can be made EU4 compliant.
Where exactly is your source on it improving emissions and economy? Caterham are doing it for cost! You need to be a bit more cynical. Throttle bodies are better all round... aside from cost. Specifically, how exactly can a plenum make an engine more efficient and economical?
As I understand it with throttle bodies of any variety you get fuel stand off which harms the hydrocarbon emissions and having a plenum enclose the inlets nearly eliminates this and means you can do breather recirculation easier.
And of course throttle bodies are louder which you might consider a good thing but it is an emission and there ar limits on noise.
Of course I could be wrong.....so don't kill me!
>> Edited by bertie on Friday 17th February 09:40
And of course throttle bodies are louder which you might consider a good thing but it is an emission and there ar limits on noise.
Of course I could be wrong.....so don't kill me!
>> Edited by bertie on Friday 17th February 09:40
If a plenum eliminated this, then an airbox around the throttle bodies would serve the same purpose surely? The only difference is really individual throttle plates per cylinder rather than one serving the plenum, since the inlets will still have trumpets inside the plenum. Airbox solves the noise issue too.
So I still think it's just the cost saving of individual throttles. Happy to be proved wrong though, and I can see your point about recirculating the oil breather I guess.
So I still think it's just the cost saving of individual throttles. Happy to be proved wrong though, and I can see your point about recirculating the oil breather I guess.
Gassing Station | Caterham | Top of Page | What's New | My Stuff