HerrFlick wrote:
....... My CB750 Four cafe engine is the next on the list
That sounds good. I feel some velocity stacks coming on! What injun? Sohc or dohc?
Moderators: Gromit, Paul, slparry
HerrFlick wrote:Corvus wrote:HerrFlick wrote:kfrogzx7 wrote:Yes Corvus, that's my understanding too.
I'm not sure of what the actual process is but the wave rebounds when it reaches the end of the tube and travels back down to the inlet valve.
That's what I've always understood anyway.
Oh absolutely right.
It's when you've got more cylinders to play with you can use these tricks to make things much more betterer.
Cool!
The gains on your torque curve graph looked healthy enough, with surprisingly little loss of max power.
Regarding effect on AF ratio, this phenomenon doesn't really seem to be interfering with actual air flow or the various devices monitoring mass flow. Just making sure that what air and fuel mixture does find its way in there is not allowed to be pushed back out. Keeps it tightly packed in there. At the rpm zone in question. Is that a fair comment?
That's the only way I can understand it too Corvus. The AF ratios showed the mixture was not leaning out at all.
Funny thing is that the 'S' has smaller valves than the 'GS' yet makes more power. Huh?
When the GS tubes are put on an RT there's an 8 hp loss at the top end and not quite the same torque gains.
I can only explain this by the gas speed in the 'S' being higher than in the other engines.
In light of this it's sort of sad to see so much money being spent on exhaust systems, air filters, porting power commanders etc for not a lot of gain when the root cause of the problem was in the intake runners. Thing is, had a mate not put me on the RT forum I wouldn't have found this and I'd be out there spending big too. LOL.
I would imagine putting The Choobs on a bike with all the other stuff done would really bring it to life.
One Trixter, SL Parry (?), already had Lennie's sprockets when he fitted The Choobs a couple of years ago. Reckoned all hell broke loose at 4k rpm.
Hoping to fit my rocket sprockets v.soon.
I used the same concepts in the intake manifold on my 928 S4 Porsche. Got similar results. It was the same story there: ppl spending $$$$$ to get OK results but running into a ceiling where, for the money spent the gains weren't all that great.
I'm lucky to have stumbled across this stuff because let me make the 1100 and the 928 so much more fun for not many $$$. My CB750 Four cafe engine is the next on the list
Corvus wrote:HerrFlick wrote:Corvus wrote:HerrFlick wrote:Yes Corvus, that's my understanding too.
I'm not sure of what the actual process is but the wave rebounds when it reaches the end of the tube and travels back down to the inlet valve.
That's what I've always understood anyway.
Referring to data next to pictures. Doesn't seem to be any valve overlap? Are the btdc and atdc mixed up or is that really it? Maybe I'm getting confused.
Corvus wrote:Thanks again HF. Very informative.
Went a looking for more info and this link seems good (for laymen like me).
http://www.enginebasics.com/Engine%20Ba ... iming.html
Cheers
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