aspeed

The Cox throttle is not that much different than the OS LA .10 throttle, which has no airbleed. It works fine. Mr. Cox, your English is pretty good, and even the spelling is.

rcuser004

My Feedback: (287)

Thanks Bernie...well said!

Mr Cox

On the contrary, they are very different. The most important difference lies in where fuel jet is positioned, On the OS engines (as on most other engines with carburetors) the fuel jet i positioned inside the rotating barrel such that the two sides of the barrel makes a "throttle valve" and a "choke valve", respectively. The fuel delivery at the low ends is thus adjusted by adjusting the level of air that is allowed to bypass the choke valve (i.e. the upper part of the barrel orifice).

I don't know about the OS .10LA but the OS .10FSR doesn't have any air-bleed either. This doesn't mean that there is no compensation at the low end though, as there are several other ways to do it. On the OS .10FSR there is a larger bore above the barrel compared to below it, such that the "throttle valve" closes before the "choke valve" and the low end is kept lean. On other engines there is a slot or a hole (plain bearing MP Jet for instance) made in the upper part of the barrel, thereby making a similar type of compensation. On Norvel engines the slot is instead in the part that the barrel will close against. An air-bleed hole (fixed or adjustable) serves just the same purpose, it lets air bypass the "choke valve" and keeps the low end lean.

Andrew

I think much of this discussion has gotten mired in semantics and/or interpretation. I've no problem with calling the COX throttle a throttle --- in short, it allows me to control engine speed; how that is managed is of no concern. The carbs (throttles) on many of the small displacement engines are nothing more than chokes designed to restrict air intake. This is especially true if the carb has no mixture adjustment screw or air bleed. By restricting airflow, it also reduces fuel flow due to lower air velocity in the venturi. It's similar in the COX throttle --- lower air flow reduces the venturi effect and ultimately the amount of suction at the fuel outlet.

NORVEL's approach was novel in how the throttle barrel is retained. Because it screws into the carb body rather than being retained by a screw, it allows the mixture to be leaned on the idle end as the barrel and attached needle move inward as it rotates.

Red Baron Mike

Yes, I do remember full house; I remember reed radios; heterodyne and super heterodyne receivers; tuning wands and paraffin; tube type transmitters and B cells; and rubber band escapements. What I can't remember is what I had for breakfast.

Mr Cox

Yes, that is true, there will be a reduction of the fuel due to the clever construction with threads to move the barrel in and out. The effect is not large enough though, they have also added a slot to the carb body to reduce the choking effect of the upper orifice in the barrel. On the Norvel .074 this is easily seen with the intake screen removed;

binns aero

way to go Bernie ! Started with Cox a long time ago. Found many a cut with good-old "M-Mist", got real dizzy and flew to high many atime prayin it would run out of fuel. Love those engines!!!

aspeed

Bernie, there is an Ace throttle that was available for $2-3 a long time ago. http://www.coxengineforum.com/t5486-...nturi-throttle . It would work with a muffler I assume. It would be simple to reproduce. It is about half way down the page. There was also a muffler made by Cox? that was a throttle ring that worked fairly well. It had a silicone sleeve over the outside that would burn off after a while. Quite a while I think. Either one of these would give a muffler and throttle. I could take a pic. of mine if you want.

Cox International

My Feedback: (10)

Yes, I know about the ACE throttle. Retail pricing would be in the $20+ range with a production run of 1,000. As for the RC Bee / Dragonfly muffler / throttle, retail price would be in the $30+ range with a production run of 1,000; meaning it may not be a commercially viable project.

Bernie
www.coxinternational.ca

DaveyMo

Folks:

With apologies for slight thread drift here, I've a question. Does anyone know if NV Engines is still in business? I posted to the Norvel site here and got no response. For what it's worth, I like both Cox and Norvel for different reasons. Am very glad that Cox International makes parts available - would like to see the same for Norvel.

Dave Mo...

Cox International

My Feedback: (10)

http://www.nvengines.com/

DaveyMo

Bernie (or anyone else who can help):

Thanks for the Norvel link. I've tried registering and ordering but (oddly) I get no acknowledgement through their web site. Even my e-mails aren't answered. Could you kindly provide a phone number?

Thanks very much!

Dave Mo...
Baraboo, WI

Cox International

My Feedback: (10)

Dave,

Back in 2010, Alex, the fellow who operates the site, gave me his phone # as 562-728-4230. I just phoned there and some fellow (with strong Russian accent) said that Alex was not in and it would be best to email Alex. The email we have on file for Alex is [email protected]

Please also note that we are not affiliated with Norvel; not that we do not wish them all the best of course

Bernie
www.coxinternational.ca

Mr Cox

I haven't bought anything from the Norvel site for quite some time (about a year or more), so I don't know how they are doing now.

I believe Alex has the ebay username "honestguy" and he will sell engines through there as well; http://www.ebay.com/sch/honestguy09/...1&_ipg=&_from=

DaveyMo

Bernie and Mr. Cox: Much obliged for the responses from each of you. There must be some kind of activity yet, so I'll give them a try and let you know how it turns out. Thanks!

Dave Mo...

Pond Skipper

http://www.ebay.com/itm/norvel/27160...=nc#ht_25wt_99

http://www.ebay.com/itm/NEW-NORVEL-0...nc#ht_25wt_999


http://www.ebay.com/itm/Norvel-big-m...nc#ht_25wt_999


http://www.ebay.com/itm/074-R-C-Airp...nc#ht_22wt_999

aspeed

The last ad says it is a Queen Bee, If the picture is correct, it is a Norvel. Much better than the Queen Bee.

049flyer

My Feedback: (18)

I like both Cox and Norvel engines but each is best suited to their own type of aircraft. Smaller lighter airframes get the Surestart and larger airframes the Norvel. That said, I usually prefer my Cox powered planes because parts are readily available, so no worries about mishaps. The Norvels engines are great but if the ground rises up to smite my plane then it's a problem finding the parts if I need to fix the engine.

combatpigg

My Feedback: (3)

I feel the same way. If you build light enough, Cox engines can deliver outstanding performance for less money than Norvel.

The Killer Bee is by far the hottest .049 Cox ever built.

DaveyMo

Bernie and Others:

I contacted NV Engines through Alex's e-mail address, and he is being very responsive and helpful. Thank-you again for your assistance!

Dave Mo...