3 years waiting, my Bailey jet engine finally arrives!

[Bruce Tharpe]

I'd have to dust off my AMA rulebook, but if memory serves, it dictates a max diameter for both the combustion chamber (2-1/2") and the tailpipe (1-1/4"). Both dimensions taken directly from the Dynajet, of course. Someone please correct me on this if I'm wrong. If that's the case, it looks like the Bailey actually necks down below the 1-1/4" tailpipe diameter. I'm guessing some trial and error work was involved during that 3 years.

Conor, the Double Whammy uses two plain ol' Dynajets. The only mod we like to make is to replace the flowjector with Bailey flowjectors and metering jet sized for methanol.

Troy, the Laser Arrow is a bit smaller than the Shockwave/Delta Vortex, so it would definitely be faster. Overpowered? No, but the extra speed, to me, can actually make a model less fun to fly. You're always at full throttle, so a fast model almost needs to be in a constant turn just to keep it in sight. Does the Laser Arrow even have landing gear? Good luck with hand launching <grin>.

[Mark]

There was some plans I read somewhere where a simple pulsejet was made out of a aerosol can and fence post pipe, all held together by 4 screws, (all-thread) that ran the length of the pulsejet! Anyway, this odd to be sure design, had a slight simple flattened choke in the exhuast tube very near the neck of the can.
I guess he found that choke an improvement along the way.
Mark

[paco]

Hello Troy and all:

First of all congratulations for receiving you engine and for not spending you money for nothing. 3 years if a lot of time, and I have I can understand you, because 2 years ago I send money to Bruce Simpson and until today I have not receive the engine or the money despite he always says the engine is ready for shipping........

I hope one day I may have the same luck as you, becuase I know it is a desperate situation :-(

PACO

[Troy R. Legner]

Paco,
I know how you feel. It is a bad feeling to think that you have thrown away your money, and have been ripped off. At least I knew that Bailey machine was well known for its engines. After time goes by, that grasp for hope fades away also.
I am happy with my engine. It is a real work of art. I don't know that I would want to do it again. I had better make it last.
Troy Legner

[paul skinner]

Hello Troy and all:

First of all congratulations for receiving you engine and for not spending you money for nothing. 3 years if a lot of time, and I have I can understand you, because 2 years ago I send money to Bruce Simpson and until today I have not receive the engine or the money despite he always says the engine is ready for shipping........

I hope one day I may have the same luck as you, becuase I know it is a desperate situation :-(

PACO

Not trying to start a war here, but what has Bruce said?

Why no engine, and no money?

He seems to be a straight up kind of guy, so this seems really odd.
Have you asked him to return the money?

Again, just being nosy, not try to start a war here...

:)

[paco]

Hello:

With that nick I dont know who you are, but ok... As I don´t have your email I can not writte you in private.

Don´t worry, I´m not trying to make any war, just wanting to let know to Larry that I have (I am ) in the same situation.

As for what happened last time after the messages in the DIY list, well I told him that I wanted my engine for my birthday (7-nov) or my money back and gave him my paypal account. He said he had laing arround an engine that he could send me, but he needed to receive some material to finish something of the valve grid os something like that. After my birth day received and email saying he had received the metal that day and that afternoon he will machine it. After that day..... nothing until today (november, december, january)... It is not a matter just of someone not doing what he promises, but what really hearts me is the lack of motivation, of trying to solve the problems. If I was in that situation, I think I would not be able to sleep correctly knowing I own an engine to someone since soooo long...

But I really respect honestly that some people think he is a great persone, but not with me...

Paco

[paul skinner]

Hola Paco.

Lo siento si yo lo trastorné. That is not my intention. I do not publish my email address because I was endlessly harrassed by Ivar.

I am however not secretly Bruce. :)

I did not say he (Bruce) is a great guy. I do not even know (of) Bruce personally outside of his appearances on "JunkYard Wars", and this forum.

Maybe he will cough up now that sales of his CD on ebay seem to be doing well and he has his new book out. I cannot imagine he is strapped for cash. :)

Who knows.

La buena suerte.

[Bill Pardue]

I know this is an old post, but my page comes up with only "2000" for year date for some reason.
It was previusly posted about Earl Bailey's death in May of 2006. There seems to be some lack of info on the two different Bailey jet engines. The first engine is the blue head Sport Jet engine that is supposed to be a perfect clone of the Dyna Jet to make it legal for the unofficial AMA Sport Speed event. The official AMA C/L speed event is usually called "Fast Jet". Both have only one basic AMA engine restriction. That is a 1 1/4 sq. in. area max. at some point on the pipe. No after burners, but augmenter would be allowed. Both Sport and Fast jets use standard 80-20 methanol-proplylene oxide fuel furnished at the contest. Sport jet is flown on two lines, where as Fast jet is either two or mono-line.
The production Sport jet engine was close to the engine show on the download page as item no. 23. However, this Bailey drawing does not show the taper in the pipe. I think all production engines both sport and fast had the pipe taper.
The "Fast Jet" engine has the 3" long head with a 1 1/4" intake throat bore that is suitable only for pressure fuel systems. This original head is no longer made by BMS, but a similar type head is now available from Jet Bill along with the actual Bailey designed pipe. Bill is also gearing up to make a Dyna Jet clone so that engines will be available for the Sport Jet event.
It is interesting to note the flowjector (spraybar) discription given by Troy Legner of the number of holes. The original Hoyt Raven head that evolved into the Bailey production head had only two holes placed vertically similar to stock Dyna Jet. The recently delivered Jet Bill engines, I believe, have a 12 hole arrangement, which I think some Bailey Fast Jets had. Troy Legner's own original design engine can be seen at -- precision-technologies.com --.
The "Fast Jet" engines are the ones that top competitors have fine tuned to over 10 lbs. of static thrust running the 80-20 fuel. No telling what they are putting out in the air at 200 mph. They have a very different low pulse rumble when they start "coming on" at that speed.
There are accurate drawings of both the Bailey Sport and Fast Jets done by Don Laird, but I am not sure of on line availability of these drawings. Don does not do computers.
I hope this will throw some light on the Bailey engines as well as presently available engines. One comment on the previous delivery problems. I wonder if Earl was concentrating on delivering the Fast Jet engines and let the Sport Jet engines take a back seat. The Sport Jets were the first of the two available in 1992 or 1993 followed shortly by the Fast Jet.
Bill Pardue

[Mark]

So to sum up the Sport and the Fast Jet both have the same pipe, it's only the head that is different and the pressurized fueling?
How much static thrust do the Sport and the Fast Jet make with plain methanol? How much thrust does the Sport Jet make using the meth/propylene mix?
On the Fast Jet, is the reed retainer different to allow more flex? Does the Fast Jet weigh about a pound, that would make the thrust to weight 10:1? Any valveless pulsejets out there that can touch that? Is the 10:1 ratio that of an augmented static Fast Jet?
Thanks,
Mark

[Mike Everman]

Wow. I don't think I've ever seen Mark ask so many questions...

[noclassmac1972]

Mark the fastjet has a different pipe to the sportjet! the fast jet pipe has a larger ID down the exhaust but the combustion chamber is the same size. yes the engine weighs just on a pound! The retainer on the fastjet has 80thou ( 2mm ) more lift. The thrust on the sport jet would be similar to the dynajet maybe 1 pound more so lets say 5.5 pounds thrust which is good enough for 150 mph! The best fastjets produce over 10 pounds this is of course measured on the ground so who knows what it is in the air. Running just straight methanol?? I am not sure as I only run 80% Methanol with propylene oxide or nitromethane at 20%. Hope this answers some of your questions??

And to answer some other questions the Victoria jet the one with funny nose has a 120ml tank at front with built in needle valve.
regards
Robert

[dynajetjerry]

Hi, Guys,

If you will permit me, I have a few comments on this thread.

First, it is my understanding that Bill Tenney persuaded the AMA staff, in about 1946, to permit entries of Dyna-Jet-powered models in CL Speed. They compromised by restricting the minimum area of the exhaust pipe to 1.25 sq. in., as Bill says, the size of the D-J. I have no info that the combustion chamber was similarly restricted. As we all know, jets were quickly given their own class, with no change is size rules.

Second, generally, unenclosed reed-valve p-js usually lose thrust as air speed increases. The reasons are not immediately obvious but may have to do with ram air shoving the burning zone downstream (some of the heat-induced expansion of the air takes place behind the engine;) a tailpipe that is significantly smaller than the comb. chamber greatly reduces this trend.

Shielding the inlet from ram air may also help but may cause other problems. Notice the "spinner" on the nose of the later Minijets.

Jerry

[Mark]

Thanks for all that information Bill and Jerry. I was wondering what the outside diameter of the Fast Jet tailpipe is, the diameter once you get beyond the necking of 1.25 inches? Is the rule on the 1.25 inches an inside diameter or outside diameter just to be clear?
Fiddling with my Sport Jet and a set of calipers, I roughly measured 1.350 O.D. beyond the neck. The actual neck seems to have an O.D. of ~1.290 which if you knocked off .040ths you get 1.25 inches. I think the wall thickness is .020ths of course.
All this boils down to my Sport Jet tail pipe with a "general" diameter for the most part .060ths over a typical Dynajet's 1.25 inch diameter. But this too is complex because of the way the Dynajet is blanked out, at least mine bought in the 70's doesn't even come out to an O.D. diameter of 1.25 inches on the "flat" sides, some sections along the length 1.225 O.D.
I hope I have measured correctly and my math correct, I'm very tired right now but curious still. I should say some parts of the Dynajet tailpipe do measure ~1.25 O.D. but again is the rule for an inside or outside 1.25?
And if you look at the cone transition on a Dynajet and then the Sport Jet, it looks like the Sport Jet would hold a bit more volume too.
So then I wonder how much more volume the Sport Jet has over the Dynajet. And then how much more thrust would a Dynajet make if it were run on the 80/20 mixes instead of regular gasoline? Or conversely, how much thrust would a Sport Jet make if it were idealized to run on regular gasoline?
But to sum up, the greatest thing I would like to know is the measurement on the Fast Jet pipe, of which I don't have. What is the O.D. on the tailpipe once you get by the 1.25 inch choke?
Mark

[Mark]

A shot for the heck of it.

[noclassmac1972]

Mark the fastjet OD is 1.47 inch (37.4mm) sportjet is 1.36inch (34.6mm) overall the fastjet pipe is 1/2 inch shorter in length

Hope this helps
Robert Bolton

PS I dont worry to much about the figures I get out and fly them 8)