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air box
On the air box of 40 merc it states not to exceed 3000 rpms without box , does or will it hurt the engine to run without air box? Would it be able to pull in more air without the air box? Would the jets have to be increased 1 size ?
Thanks for any help.
Huh? Virtually every race motor you see does not have an air box, so....
I can tell you this about one carb per cylinder motors: A standing cloud of (scary) fuel droplets will form a few inches in front of the carb at certain rpms. That "air box's" primary function is to contain that mess and prevent a nasty fire (and law suits). Silincing the intake roar is a secondary consideration.
Jeff
very unlikely on a 2 stroke with reed valves. They are true one way check valvesOriginally Posted by Fastjeff57
Since 1925, about 150 different racing outboards have been made.
Not so, old wise Professor of TSL (Two Stroke Lore). I've seen this happen on the 30 cube twin I built a few years ago--and I can assure you the reeds were sealing tightly--had them aart several times.
Jeff
I said UNLIKELY ... not impossible. Stuff like your Frankenstein motors are more likely than production motors
Since 1925, about 150 different racing outboards have been made.
Guity as charged!
Jeff
PS: Frankenstein # 3 is running great (the external reeds triple). Trailer tested it this morning and am very pleased.
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Since 1925, about 150 different racing outboards have been made.
mate i removed mine a few years back and i run it from low speed trauling to 6400 .i thought it was only there to keep the induction noise down.
i couldn't realy tell if i got any performance gain out of it thogh.
get the timing light out at night on a multi cylinder and you can see what happens with the fuel in the carb
Reeds may be one way valves but they have mass so momentum and harmonics as they are oscillating
The fuel and air has mass not to mention the sounds waves....
ight on, Powerabout!
My late friend told me of a big block Chevy he saw on a dyno. It had Hilborn injection and there was a HUGE standing wave of fuel droplets above every one of it's eight intake runners!
Just 'cause you can't see it or don't notice it, there can be a standing wave of fuel droplets in front of every carb on one carb per cylinder motors. Using one carb per TWO cylinders eliminates this due to the opposite cylinder's intake surge.
Jeff
PS: Note the rather large equalizing tube on this Yammie.
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