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Reversed Cylinders
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BigBird View Drop Down
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Posts: 4 		  Quote BigBird Quote  Post ReplyReply Direct Link To This Post Posted: 10-July-2010 at 4:16pm
Originally posted by Vintage Smoke

Hmmmmm..a shortened RZ motor....
 
I wonder if I can shorten an RD motor and squeeze it in my wifes RD200??
 
Right after I put the big block Chevy motor in a Chevette.
 
Yea you can shorten an RD case set the same way, I saw pictures of how it was done, now putting it in an RD200 chassis?  that sort of like putting an 8 horse briggs in a Schwinn stingray frame.. LOL
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Posts: 1937 		  Quote Coyote Quote  Post ReplyReply Direct Link To This Post Posted: 10-July-2010 at 5:27pm
Originally posted by Vintage Smoke

 
Hmmmmm..a shortened RZ motor....
 
I wonder if I can shorten an RD motor and squeeze it in my wifes RD200??
 
Right after I put the big block Chevy motor in a Chevette.

.
No joke. A buddy of mine in High School put a 396 in a Chevette.
Wrinkle walls and all, solid motor mounts, radiator on outside of grill, no alternator and 2 batteries in the trunk.
Oh, and no hood.
.
It still wasn't as fun as a fast 2 Stroke.
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Surewin View Drop Down
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Posts: 179 		  Quote Surewin Quote  Post ReplyReply Direct Link To This Post Posted: 10-July-2010 at 10:50pm
Originally posted by Coyote


And installing a "Funnel" on the intakes does not increase the pressure (I don't know why, at first glance I thought it would) but I have read several places that it does not.
If anyone knows why a scoop or "funnel" gives no gain, I would like an explanation.


Air is essentially incompressible below about 1/3 the mach number.  A funnel will just trade static pressure for kinetic energy, i.e. it will act just like a carb ventrui.  The stagnation pressure will remain the same, so will the total mass flux (b/c the velocity is increasing but the pressure reduction reduces the density). Unless you compress the air the intake process will see the same air mass, b/c density (at stagnation) and volume remain constant.   I hope this helps. 



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Posts: 1161 		  Quote strokersquid Quote  Post ReplyReply Direct Link To This Post Posted: 11-July-2010 at 1:46am
RG carbs are on the sides due to rotary valves
I wish they all could be ( Northern ) California bikes !!!
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Posts: 102 		  Quote manicmecanic Quote  Post ReplyReply Direct Link To This Post Posted: 12-July-2010 at 12:29pm
hi@all
i always thought about this mod,but still cant add own experiences...but over here a guy with a rd lc powered cart? uses his engine that way since years...and doesnt seem to have other problems than usual ones........;-)... 

                                       greets   Richard

link   :  

          http://kart-mal-anders.de/media/rd4l0-6.jpg
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Posts: 1937 		  Quote Coyote Quote  Post ReplyReply Direct Link To This Post Posted: 13-July-2010 at 11:18am
Surewin said
Air is essentially incompressible below about 1/3 the mach number.  A funnel will just trade static pressure for kinetic energy, i.e. it will act just like a carb ventrui.  The stagnation pressure will remain the same, so will the total mass flux (b/c the velocity is increasing but the pressure reduction reduces the density). Unless you compress the air the intake process will see the same air mass, b/c density (at stagnation) and volume remain constant.   I hope this helps.

Thanks for that.
I knew there was a reason, but lacked the understanding to explain it.
.
As to reversed engines, IMO not worth the effort unless you are using a modern superbike frame.
And then it would probably be hidden behind a fairing.
So not even the bling factor which is really the only gain.

Dave
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Posts: 283 		  Quote yellowandfast Quote  Post ReplyReply Direct Link To This Post Posted: 13-July-2010 at 9:23pm

Yeah, about the reversed cylinders, I took a long hard look at my 400 tonight and realized I wouldnt be able to do it without cutting the 2 front frame down tubes.

I dont want a cob job on my bike so I guess its just nothing more than a cool looking idea
1975 rd 250 to 350 conversion
spec II F1s
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1973 LT2 100 1900 original miles
1977 RD 400
1978 DT250
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75 DT400
00' Honda Elite 65+ mph
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Posts: 6865 		  Quote mbsteve Quote  Post ReplyReply Direct Link To This Post Posted: 14-July-2010 at 3:14pm
You also have to cut the back of the frame out to for the pipes.
www.2-strokers.com

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Posts: 1 		  Quote EErlenbach Quote  Post ReplyReply Direct Link To This Post Posted: 29-July-2010 at 1:20am
I looked at reversing a set for a fellow once. Mocked it up and looked at the need to widen the frame tube spacing a bit in the front possibly and like steve said the need to modify the frame in the rear for sure. Seemed like to much work for not enough benefit. But the idea of reversing just the left  side cylinder seemed like it might be kinda fun. (The left runs just a touch cooler) Use two right cylinders, One pipe under and one out the back.
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Vintage Smoke View Drop Down
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Posts: 234 		  Quote Vintage Smoke Quote  Post ReplyReply Direct Link To This Post Posted: 29-July-2010 at 9:48am
Originally posted by EErlenbach

But the idea of reversing just the left  side cylinder seemed like it might be kinda fun. (The left runs just a touch cooler) Use two right cylinders, One pipe under and one out the back.
 
Now THAT sounds cool!!!! Only problem I see with that is that each carb would have an exhaust pipe right next to it. You would have to rig up some heat shields.
Vintage Smoke!! Performance Parts for Vintage 2 Strokes.
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ross t View Drop Down
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Posts: 5497 		  Quote ross t Quote  Post ReplyReply Direct Link To This Post Posted: 29-July-2010 at 10:49am
Here is one for you Nick,....
 How come the XR's are not backwards..? why didnt they run the pipes out the back and use the carbs up front..? They friggin things made stupid power. Could you imagine a more modern version..?
YOU EVER HAVE SOMEONE'S LITTLE BRAT KID PISS YA OFF ?
THEN YOU SEE THE PARENT AND YOU JUST WANT TO SMASH THEIR FACE..?
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ET. 36.14 @47mph
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Posts: 1766 		  Quote mkane63t Quote  Post ReplyReply Direct Link To This Post Posted: 29-July-2010 at 11:04am
No need to re invent the wheel
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