For certain cowlings this 180 degree tuned manifold might fit
 better. It is more compact. It is based on a 3 inch center line radius 180 degree
 2" tubing bend. the center line distance is 6 X 3.1416 or 18.8 inches.
 We need 24 so this comes out about right.

 It is easier to make as there are fewer
 tig welds than the front mounted configuration.

 It is also really trick looking :)

 Paul Lamar



 Looks nice. What about having a very short "block hugger" style
 intake manifold to the carb for better packaging and then a
 plenum + long tube combo to give the needed length?

 Vlad

 It is possible that might work but the origin of the pulse that
 energizes the intake manifold takes place right at the port.
 I suspect that moving the carb near the port may seriously
 affect the tuned system. I have not tried it however. For the
 same reason you don't want to put the venturi and the butterfly
 throttle somewhere in the middle of the runners. When the slide
 throttle on the other hand is wide open for take off and for high altitude
 cruise so it has no effect.

 Paul Lamar


It does look cool--reminds me of the handlebars on my old Schwinn Varsity
(What a great bike--heavy though)

Should we be concerned about locating the carb directly over the exhaust?
Fuel fittings, hoses, gaskets and other things prone to leak fuel are
concentrated there.  Obviously, a fuel leak anywhere is a very serious
issue, but this seems to enhancd the risk somewhat.  Also, is the potential
for boiling the fuel out of the carb float bowl an issue?  If I recall
correctly, this was what caused Tracy a problem years ago with his Mikuni
carb set up.  Heat shields would help, of course, but it seems that putting
the carb farther away from the exhaust has advantages.

On the other hand, that nearby heat will reduce the chance for carb ice I
suppose.

Mark W.

Yes everything seems to be a trade off but 4 bbl carbs were
mounted for years (70 to 88) just above 1st gen RX7 exhaust manifolds.
Never seemed to be a problem. More VW's had engine fires than 1st gen RX7's.
Here is a picture of my pristine 1983 RX7.

Paul Lamar