Author Topic: nelson 65 (Read 1745 times)

david smith · « **on:** March 13, 2011, 10:56:17 PM »

Just got this thing and I was curious if anybody had ever used one or knew anything about them like what carb to use.and possibly a prop range.

Thanks David

bill bischoff · « **Reply #1 on:** March 13, 2011, 11:57:52 PM »

I don't know anything about this particular engine, but based on the RPM spec's I'd start with an APC 10x6. Locally, we've run the OS 65 DF on the APC 10x6, Webra 61 RIRE and RISE on the APC 10x7, and Rossi and MVVS front intake 61's on the APC 10x8. The key is matching the prop to the engine for best hi speed. We run on straight suction, and have had excellent results with the OS 4E carb. I believe it has a 10 mm bore. The neck will probably be way too small and need a sleeve to fit the Nelson. It's also been along time since I've bought one of these carbs, so I don't even know if they are still available.

Good luck with it. It should be a monster!

ooffy · « **Reply #2 on:** March 14, 2011, 11:31:29 AM »

The engine you have is a Galbreath/Nelson .65, and it is one POWERFUL engine. The short story is thstl oug Chapman ordered a run of 100 DC 60 Helicopter engines from Henry Neslon, but he (Chapman) died after opnly 50 were delivered. Doug Galbreath bought the remaining parts from Henry and made/had mades the .65 piston and liner, and the NVA and built 50 .65 engine for free flight use, selling the last one just a few months ago. Doug hand built these engines.

This is an all-out high performance racing engine, and would NOT make a usable R/C engine. If you are not interested in free flight, CL Speed or tether car racing, sell it on eBaay for a pretty penny and buy a good R/C engine for your application.

Ron Bennett
Monmouth, OR

Bill Little · « **Reply #3 on:** March 16, 2011, 02:35:51 PM »

HI Ron,

I will first admit I am pretty dumb about these things, but why would it not be good for carrier use? Is it that it just wouldn't be able to make idle for slow flight?

The engines I have always heard about being used in ".60-.65" class carrier event seem to be very hot "high performance/racing" engines....

Thanks!
Bill

david smith · « **Reply #4 on:** March 16, 2011, 02:54:48 PM »

The paperwork that came with it said they did some testing with a super tiger 4500 carb and that the engine didn't lose any power. Don't free flight engines run open face? If so then the timing should be ok so in theory all I should have to do is limit the air and fuel and it should idle down. It will be running on pressure so fuel flow won't be a problem. I am going to try to mess with it this weekend if I can get a carb I will post more when I find out.

Bill Little · « **Reply #5 on:** March 16, 2011, 03:00:26 PM »

HI David,

I am really just curious about Ron's comment. If it will idle, and it is as powerful as mentioned, then I would think it would be an excellent carrier engine. Isn't the idea making the plane "fast"? I do realize that slow flight is very important, too. I just can't understand where an engine would be too "powerful" unless, as I asked, it wouldn't "idle".

Big Bear

ooffy · « **Reply #6 on:** March 16, 2011, 03:28:10 PM »

Dear Bill and Dave,

The Nelson 65 is a beast of an engine and almost equal in power to the all out D Speed engines we are running today. When I said "it will not idle" I should have been more specific. It will run with a big Perry, ST, or OS 7D carb., and it will idle. What is will not do is transition very well from idle to full speed, and they is no midrange. Yes, you would most likely have high top speed, but the lack of throttle control would make it hard to handle. the other major factor is that thin is now a VERY collectable engine, selling used in the $700++ range, and that will buy a lot of much better carrier engines. The Nelson in not piped timed, but it is high timed (both exhaust and intake) compared to most other commercial 60-65 engines which were timed to run with an R/C carb. The bottom line is that the Nelson 65 will "work" as a carrier engine, but it would not be my first (or fifth - tenth) choice, and its value would lead one to other choices as well. It's not just the expenses (said the man with eight $800 Profi F2A engines), it is that it is a collectable with very limited production numbers.

IF cost is not an object, then order up a Nelson billet front end, crank and backplate for the OS 65, send them off to Phil McGee and have him build you a McGee 65 FIRE with an OS 7B/D or Webra Dynamix carb. It will outrun the Nelson and have reasonable transition as well.

An OS 65VR, or a Rossi P65 would be much better choices in my opinion. If you like exotics, hunt up a CMB 10cc R/C if for no better reason than the machining on the billet carb. is a work of art. Or, a Webra with the Dynamix carb. (or the Dynamix carb. on any other 65) would be a good choice. If you are building from a Nostalgia kit, then the HB 60 PDP would be a great choice.

Ron Bennett

Bill Little · « **Reply #7 on:** March 16, 2011, 03:47:32 PM »

Hi Ron,

Thanks for the explanation. I understand what you're saying, and it makes perfect sense!

Bill

david smith · « **Reply #8 on:** March 16, 2011, 10:58:37 PM »

Well your explanation makes me feel better about buying 2 of them. They would have both been still in the shrink wrap except I got excited and opened one. Oh well thanks for the explanation it makes more sense now.

eric david conley · « **Reply #9 on:** March 25, 2011, 07:58:25 PM »

When I first started using the Nelson engines in carrier it was difficult to get them to transition from idle (idle was fine) to high speed because they would go rich and quit just as you were going through the RPM range where you would normally run them to hang. It took several years and several different carburetors to get them to run reliably but it was sure worth it once I got things sorted out. I never ran the 65 but do run a de-bored 40 in Profile (36) and a 40, and a 45 which was the Nelson outboard engine. They all run hard, fast and last forever. I'm still running the 36 I got in the mid 90s without any repair work to date and it is my strongest 36 out of the three I have.
I run the 45 in CL-2 and although its has never been a National contender for fist place at the Nats it has done quite well. These engine are all now much easier to set up thanks to Henry introducing the hotter plug (big hole plug) which lets the engine transition through that wet spot and also run real good at hanging power. The carburetors that I have settled on are "Perry's" of various sizes. The OS carburetors that Bill mentioned have always worked quite well for everyone but me. I cant believe the engine you have cant be made to work well in carrier mode. Eric

john e. holliday · « **Reply #10 on:** March 26, 2011, 07:01:35 PM »

As Eric says, any engine can be made to work, but it takes effort.

ooffy · « **Reply #11 on:** March 26, 2011, 07:53:41 PM »

Yes, any engine can be made to work, but how well does it works is the real question. The Nelson 36 and 40 in the Combat case make excellent Carrier engines because of their open timing. The are completely different designs than the big case 29-36-40-41 front and rear intake Nelsons, and the Nelson 65 is a completely different animal as well - no comparison. A Chevy Nova is no relation to a Corvette, no matter how its tuned. But, the Nelson 65 (we should actually call it the Galbreath 65 since it was built from a pile of parts from the dead DC 60 Helicopter project with new piston and liners to Doug's specs) was designed and built for an completely different application.

It is built and timed to haul a 1000-1300 square inch high lift airfoil model to a quarter mile height in ten seconds. The timing makes it impossible to idle and anything near that needed for Carrier.

It's kind of like trying to drive an IMSA GP1 car or a NASCAR car in city traffic. It can be done, but more likely than not, one would find themselves going way to fast too soon, having spent way too much money for the pleasure.

My point was that the Nelson 65 is A: too valuable; B: too critical with a very limited RPM range; and C: not able to idle at a usable range for Carrier.

I could make a exhaust throttle for one of my McGee 65 D Speed engines and have some kind of limit RPM range, but what would bee the point? The thrill of folding wings at speed and scaring all of my competitors in the process?

When the rules are changed to weigh the high speed and reduce the slow speed scoring emphasis, then "ball-to-the-wall" speed engines will be more attractive for Carrier. Now, if that wre to happen, I have a bunch of game-changing engines we can talk about . . .

Ron Bennett

eric david conley · « **Reply #12 on:** March 27, 2011, 11:31:09 AM »

I hope that your intention David is to build and develop the most badest CL-2 carrier plane around that you will campain as much as you can and then go to the Nats and see if you can get first place in CL-2 AMA carrier. Believe you me when I say it will be a tall job to knock the likes of Pete Mazur off the pedestal at this time. If this is in fact your intentions then I think the successful development of the Nelson engine you have acquired is a great way to go. If on the other hand you want a great engine in what ever plane you want to build for AMA CL-2 carrier to take around to a few contests for show and tell I don't think it wise to go with the Nelson 65 that you have.
Its always nice to have the fastest plane in any given carrier event but unless you can also have the best or very close to the best time in low speed your efforts will be for not (I know from experience) as far as being top gun in CL-2 carrier. So have at her, and I wish you the best in this project. Eric

Author Topic: nelson 65 (Read 1745 times)

david smith

nelson 65

bill bischoff

Re: nelson 65

ooffy

Re: nelson 65

Bill Little

Re: nelson 65

david smith

Re: nelson 65

Bill Little

Re: nelson 65

ooffy

Re: nelson 65

Bill Little

Re: nelson 65

david smith

Re: nelson 65

eric david conley

Re: nelson 65

john e. holliday

Re: nelson 65

ooffy

Re: nelson 65

eric david conley

Re: nelson 65