Anyone know what this is?

[David Santistevan]

I bought this a few years back but i dunno what it is?!

 

[Tom Levescy]

cmb 67 w/exhaust throttle and vintery

 

[Danny King]

Nice piece. Worth trying for sure. Don’t see em much anymore.

 

[camaroboy383]

Tom hit the nail on the head...

Ac

 

[happybradboating]

Hi David, I ran this setup on some old Picco 45's, 67's & 80's engines with riggers. The thought from my understanding was improve throttle response. I do not think it made any difference in my option. It will work on any engine such as the CMB you have so that is about it. The only other problem, I remember fighting with throttle linkage and the motor staying on part way open. I wiped out more than one set of boom tubes and/or sponson(s) with throttle linkage issues. Brad

 

[brad nichols]

It was the hot set-up with instant throttle response and I think it kept heat in the motor when running slower. It as everything in our hobby had to be worked on and tested, but carbs are simpler, lol Just the way it goes, we use to run rotors that had to be lapped and set, now we have the drum which takes longer to spool up but they don't require much maintenance.

Brad

 

[David Bryant]

I believe that exhaust throttle is a Gardner brand? And I'm pretty sure the venturi was made by Gardner, they were very popular at the time (sold by Tidewater Engineering and others). In the case of this CMB engine, the exhaust throttle's clamping mechanism (on the exhaust-port side), is secured onto a (trimmed-down) stock CMB header section. This allows you to install the exhaust throttle assy using the normal header retainer spring(s). Otherwise the exhaust throttle (exhaust-port end) would be custom fabricated to fit onto the exhaust stub.

Yes, like Brad say, the exhaust throttle yields slightly more instant response compared to a carb. But an engine is better managed by a carb (I feel)

 

[Matt Krieger]

I spoke to MR. Gardner in early 2000’s , really nice guy. Is he still around?

 

[David Bryant]

I spoke to MR. Gardner in early 2000’s , really nice guy. Is he still around?

I have no idea?

 

[Geraghty]

It was the hot set-up with instant throttle response and I think it kept heat in the motor when running slower. It as everything in our hobby had to be worked on and tested, but carbs are simpler, lol Just the way it goes, we use to run rotors that had to be lapped and set, now we have the drum which takes longer to spool up but they don't require much maintenance.

Brad

The rotary exhaust throttle had a couple of issues that could be difficult to deal with.....
1. Exhaust throttles had a propensity too gall and stick......two dis-similar metals rotating against each other really reduced galling....that is why you see a brass barrel in an aluminum body.....
2.When you pull back the throttle on a carb the mixture will go a bit richer and at times you can save a lean run and finish the heat and or not damage the motor or plug.....carbs are just easier to to deal with....
3.Back in the day several people made exhaust throttles I.E. Gardner,Brey,Prather,etc.etc etc.
By in large they were big heavy and just not the best way to go....The advent of the carb basically killed the exhaust throttle market....