stunthanger.com

Engine basics => Engine set up tips => Topic started by: Phil Goldberg on June 19, 2015, 10:32:12 PM

Title: New Old Stock McCoy .35
Post by: Phil Goldberg on June 19, 2015, 10:32:12 PM: I just purchased a new old stock McCoy .35 red head. It appears to never have been run. My plan is to put it on an classic stunt model like the Magician from Brodak or a Ringmaster. Can anyone give me any advice on subjects like breaking in, what type of fuel, prop for stunt etc. Any info would be great. The motor cost me $50. Thanks.
Title: Re: New Old Stock McCoy .35
Post by: Brett Buck on June 19, 2015, 10:48:09 PM: Quote from: Phil Goldberg on June 19, 2015, 10:32:12 PM
I just purchased a new old stock McCoy .35 red head. It appears to never have been run. My plan is to put it on an classic stunt model like the Magician from Brodak or a Ringmaster. Can anyone give me any advice on subjects like breaking in, what type of fuel, prop for stunt etc. Any info would be great. The motor cost me $50. Thanks.

Follow the directions, but to first approximation, 25-28% all castor, blubbery rich for a long time, with occasional heat cycles, 8-6 prop for break-in working your way up to a 10-6 for flying. Figure that you will need to accumulate around an hour and a half or two hours on the bench with short runs (5 minutes followed by about 10 minutes to cool), so get some hearing protection and get ready for a really long day.

Brett
Title: Re: New Old Stock McCoy .35
Post by: Bill Little on June 19, 2015, 10:51:16 PM: Brett is dead on for his post. There is a post by Randy Smith in Engine Tips section called "Care and Feeding of the Stunt Engine". Read that a couple times! :)

BIG Bear
RNMM/AMM
Title: Re: New Old Stock McCoy .35
Post by: Phil Goldberg on June 19, 2015, 11:41:48 PM: Wow, a bit of an ordeal. I can do it though. Just, where can I find that kind of fuel. I am assuming that you mean there should be no synthetic oil? What percentage of nitro?
Title: Re: New Old Stock McCoy .35
Post by: Brett Buck on June 19, 2015, 11:48:01 PM: Quote from: Phil Goldberg on June 19, 2015, 11:41:48 PM
Wow, a bit of an ordeal. I can do it though. Just, where can I find that kind of fuel. I am assuming that you mean there should be no synthetic oil? What percentage of nitro?

Probably shouldn't use synthetic, as it counts to some degree on carbon/varnish formation to seal up the piston. I would suggest 10% nitro. As to where to get it, SIG sells or at least used to sell all-castor fuel.

NOTHING is more important than break-in for these types of engines. You *must* go slowly and carefully.

Brett
Title: Re: New Old Stock McCoy .35
Post by: Steve Helmick on June 20, 2015, 12:08:37 AM: Call Scott Riese (or send him a "PM"...he's a member here). He should be able to point you to a local source of fuel...maybe Tammy's in Beaverton. Tim and Tom are over yonder by OC, if that helps. Tim will chime in shortly, probably. What part of PDX are you in? Delta Park is the usual flying site there, tho Tim & Tom fly out SE somewhere with the R/C bods. If you ever get to Eugene, then be aware that Eugene Toy & Hobby carries SIG fuel. Corvallis? Trump's might possibly carry decent fuel.

One of the benefits of using a modern engine is that they are generally very happy with available fuels, with perhaps a little "doctoring", like some Aero-1 or extra oil...either synthetic or castor. This is because we can't just throttle it back, bring it in and re-set the NV.

Brett is spot-on about fuel. I'd suggest cutting down a 10-6 to 8", rather than using a stock 8-6, for a paddle-blade prop with a lot of flywheel effect. H^^ Steve
Title: Re: New Old Stock McCoy .35
Post by: Bill Johnson on June 20, 2015, 06:31:14 AM: Quote from: Phil Goldberg on June 19, 2015, 11:41:48 PM
Wow, a bit of an ordeal. I can do it though. Just, where can I find that kind of fuel. I am assuming that you mean there should be no synthetic oil? What percentage of nitro?

Check with your local hobby shops and see if they carry or can get PowerMaster fuels. I use their 10/29 GMA fuel for breaking in older engines. It's 10% nitro and 29% castor oil.
Title: Re: New Old Stock McCoy .35
Post by: Phil Goldberg on June 22, 2015, 12:42:23 PM: seems very difficult to find all castor fuel locally. If I order it on line there is a quite substantial hasmat shipping fee. Can I just add pure castor oil to my castor/synthetic blend or does the McCoy .35 break in not like synthetic at all? Also after break in is completed can I use a fuel with synthetic in it?
Title: Re: New Old Stock McCoy .35
Post by: Dave_Trible on June 22, 2015, 06:07:03 PM: I believe if the engine is actually new or has had very little running the castor/synthetic mix is fine if used exclusively and should make these old engines last longer. Yes I add pure castor up to around 28% total oil. The trouble is in using synthetic oil where the all-castor varnish has built up in the engine. The synthetic oil cleans away the varnish and maybe the compression with it. I've had good luck in this with all the old engines I have as long as they started new.

Dave
Title: Re: New Old Stock McCoy .35
Post by: Paul Walker on June 22, 2015, 07:19:49 PM: The McCoy 40 I used in my VSC Skylark was reworked by Tom Lay. He made it very clear that only all castor fuel was to be used, no synthetic oil at all. I followed his "orders" and it ran great the first time and 5 or so years later as well. If it was my motor I would only use all castor fuel.
Title: Re: New Old Stock McCoy .35
Post by: RandySmith on June 22, 2015, 07:36:50 PM: Yes you can use a blend of oil in the new McCoy you have, I would use 25% castor with 3% synthetic, it will last longer, stay cleaner and run better for longer.
I have several engines that I have ran since the 1970s, they have been ran on a blend of castor and syn. oils, we have better ones today. My engines are still in great shape including 3 Foxes (35s) a 35 McCoy, and about 4 OS 35S engines

Randy
Title: Re: New Old Stock McCoy .35
Post by: Garf on June 23, 2015, 02:24:37 PM: If you are lucky enough to have an engine that was fitted tightly, (rare) you can run 25% castor and 5% synthetic. I would still run straight castor. I run 20% castor and 5% klotz on the LA 46 and they run great.
Title: Re: New Old Stock McCoy .35
Post by: Phil Goldberg on June 25, 2015, 01:48:08 PM: Scott Riese very graciously broke in my McCoy .35 on his engine stand. The engine is very good and I am building a RSM Ringmaster to (fit around it). I have the original McCoy gold plug that came with the engine but this was not used to break in. I want to keep the plug for nostalgia. What plug should I put in it. I have a OS #6 however it seems much shorter reach than the original gold plug. I forgot what Scott was using to break in. Thanks
Title: Re: New Old Stock McCoy .35
Post by: Scott B. Riese on June 29, 2015, 07:52:41 PM: HEY......Or HAY. The McCoy we ran is not ready for a plane. We only ran 8 oz a fuel through it. WITH a 10x4 and at 8800-9300 rpm's you can get this engine ready for a plane in an afternoon. I'M ALWAYS willing to help and close by. I collect McCoy's and have over 100 ready to go. The engine we ran the other day IS by far over-compressed. HOWEVER, The head temps are with in tolerances. 180 or less. It needs running on a test stand. MAYBE a 1/2 gallon more. The test stand we used is ALWAYS ready for anyone that needs a stand. I built it for the club. ANYONE can use it.

Scott

Call me if you need help!
Title: Re: New Old Stock McCoy .35
Post by: Scott B. Riese on June 29, 2015, 07:54:27 PM: Quote from: Garf on June 23, 2015, 02:24:37 PM
If you are lucky enough to have an engine that was fitted tightly, (rare) you can run 25% castor and 5% synthetic. I would still run straight castor. I run 20% castor and 5% klotz on the LA 46 and they run great.

LA and McCoy can not use the same fuel
Title: Re: New Old Stock McCoy .35
Post by: Scott B. Riese on June 29, 2015, 07:57:19 PM: Quote from: RandySmith on June 22, 2015, 07:36:50 PM
Yes you can use a blend of oil in the new McCoy you have, I would use 25% castor with 3% synthetic, it will last longer, stay cleaner and run better for longer.
I have several engines that I have ran since the 1970s, they have been ran on a blend of castor and syn. oils, we have better ones today. My engines are still in great shape including 3 Foxes (35s) a 35 McCoy, and about 4 OS 35S engines

Randy

Phil...This is the same fuel you where using the other day. This is what I use in ALL my McCoy's and all cross flow engine's.
Title: Re: New Old Stock McCoy .35
Post by: RandySmith on June 29, 2015, 09:32:24 PM: Phil it doesn't matter to me if your engine uses any fuel you want, however I have many decade of testing and looking at thousands of engines that have been run for a long time, plus I have been able to do many real world scientific test on oils and fuels, what I told you earlier in this thread is spot on.
please read the excerpt below: The additive Aero-1 I make will also help the motor run for much longer time than normal, and will reduce friction, but the best thing is it is heat sensitive and is much more active as heat rises. It has been around for decades, many many modelers use it in all form of aeromodeling,

Randy

Fuel is one of the most critical aspects in running model motors. Use the right fuel and you will probably notice nothing; the wrong fuel will have you grumbling, or worse, will have your motor screaming, belching and running with absolutely no consistency whatsoever.

Most fuels on the market today use a synthetic base and are blended for the R/C sport flier. These are typically very low on oil content, usually in the 12% through 15% range. This is never acceptable for our use in C/L Stunt. There are many reasons but the most important is the fact that we normally do not run our engines in a peaked two cycle, but rather a broad range of four cycle and rich two cycling. Any time you run with the motor set to come on and off in the maneuvers (like a typical 4-2 break) you are not only asking the fuel to lubricate the motor, it also has to cool the engine. The only way you can run in a 4-2 is to heat and cool the parts in the combustion chamber very rapidly. This makes the oil content critical, because it’s the unburned oil that helps carry away the heat.

Years ago, most fuels had only one oil ,castor. This is still a very good oil with many good but some bad points. Some of its good points; it carries heat out of the motor and gives a good plating action on all surfaces, especially when they’re hot. It also has tendencies to move toward hot surfaces, helping to protect them. A few of its bad points; it burns and sticks to the piston sides and the ring groove and all other parts that are hot enough, and will carbonize the chamber. It will stick rings in their grooves, freeze wrist pins and build up ridges on sleeves. This causes excess friction and heat and will ruin your motor in time.

The alternative to castor is synthetic oil and almost all fuels have these in them; the vast majority has all synthetic. Virtually all fuel manufactures use one type of synthetic; these are normally polyalkylene glycol based oils. They are mostly made up of alcohol started linear polymers , of oxypropylene groups. These are made by several companies and are available in a large range of molecular weights and viscosities.

This group of oils is the modern version of the old Ucon oils and also have good and bad points. Some of the goods points; they are very good lubes without containing any wax; they have outstanding load carrying capacity, film strength, anti-wear properties, are resistant to sludge formation, and will help keep your engine clean. The bad points are they give no rust protection by themselves, they don’t plate hot surfaces as well as castor and they burn at high heats.

As you can see, both oils have advantages and disadvantages to them; it’s for these reasons that they work much better blending together than they could ever work alone. Throughout many years of flying ,testing and other research have proven this to me beyond any doubt; plus you can see this for yourself. Recently, a friend of mine had a motor that would go into the pattern and lean out and act very inconsistently. The only change that was made was to substitute one tank of my fuel in the model. The results were drastically different; the motor now ran very smoothly, going into a two cycle instantly when the nose was raised and back into a four cycle instantly when the plane was leveled. This was tried back and forth both fuels; his and mine. The results were the same every time. I see this type of thing happen much too often, and it is extremely frustrating for Flyers to deal with. They often blame these fuel problems on cooling, cowlings, motors ,fuel filters, and unfortunately some don’t have a clue how to recognize or solve this problem. This is a frustration that you can live without!

I would like to tell you there is one Stunt fuel formula to run in all motors, I said I would like to tell you that…unfortunately this is not the case, and will never be as long as we have such a wide range of motors and running styles. What I will tell you is a good formula for the most common types of engines. Make sure you pick a fuel supplier who will give you consistent fuel day to day ,and will blend fuel for your motor needs or has fuel to match your needs. Stay away from any supplier who will not tell you the oil percentage, or who say one type works for all motors. I see this much to often also, It is unfortunate, but a lot of fuel manufactures will try to fool you about the oil and nitro percentage. One trick is to measure the oil by weight and all other ingredients by volume. Or measure it all by weight , you will be shorted on both oil and nitro that way, since the both weigh more than methanol Doing so, they can claim that the fuel is for example 18 % oil , when in reality it is only 14.9 % oil content . Other things are changing oil types, going to cheaper Nitro’s, and adding in other types of Nitro parrafins.

So what percentage do you try? For motors like Fox .35s, OS Max 35s or the old McCoy’s and K&B’s, use a fuel with 26 to 28% oil content; preferably half castor and half synthetic, up to 75% castor is OK. These motors have very small bearing surfaces, and are subject to much wear and heat, most are all plain bushing motors and most have unbushed rods. They need a lot of oil to help cool the engines. Since these motors run hot, they need extra oil to keep them lubed,clean, and to carry out heat . If you have one of these that is in very good shape but, is just starting to get some brown or black varnish plating on it, the synthetic mix will clean it up for you, resulting in increased life. Do not use the synthetic blend in an old motor that has a lot of time on it with all castor fuels; the synthetic will remove the castor varnish off the piston and sleeve and will in some cases, leave you with the worn-out motor that had to start with. Also always try to NOT use prop shaft extensions with these engine, as it adds a lot of wear on the crankshaft bearing.

For motors with larger bushings and bushed rods like to OS FP , Magnum GP series, Tower, and Brodak’s a 22-25% half-and-half oil mixture works the best. For S.T. .46 51,and .60s and most all ball bearings Stunt motors, a 23% half blend works best. Again the Synthetic blend will help keep the engine clean, and insure long life. If you use all castor in these types, it can stick the ring in the groove , resulting in poor compression and shortened engine life. If you have a ringed engine that castor has gummed up badly, most times running the synthetic blend will free the stuck ring, and the engine will return compression and power for you.
The tuned pipe motors like a little more synthetic and I recommend a 15% synthetic, 7% castor blend or a 20% half and half with 1 ounce of Aero-1 fuel supplement. Although many use 1\2 – 1\2 with great success. This works very well in the Precision Aero , OPS and Max VF engines, Super Tigre Thunder Tiger, AERO TIGER and most all of these type engines..
Title: Re: New Old Stock McCoy .35
Post by: Scott B. Riese on July 01, 2015, 06:32:47 PM: Great Stuff Randy!! I know lots of people that need to read this. SO can I copy this and hand it out?
Title: Re: New Old Stock McCoy .35
Post by: RandySmith on July 02, 2015, 03:43:05 PM: Quote from: Scott B. Riese on July 01, 2015, 06:32:47 PM
Great Stuff Randy!! I know lots of people that need to read this. SO can I copy this and hand it out?

Yes please do

Randy
Title: Re: New Old Stock McCoy .35
Post by: Scott B. Riese on July 02, 2015, 03:51:26 PM: Quote from: RandySmith on July 02, 2015, 03:43:05 PM

Yes please do

Randy

Thank you. I just had a customer run a new McCoy 35 8x6 at 10000 plus............Bad things happened. SO who is reconditioning piston and liners for older engines. I should have made a new post.

Scott
Title: Re: New Old Stock McCoy .35
Post by: frank mccune on July 02, 2015, 05:56:38 PM: Hello Scott:

I think that you may be referring to my experience with a McCoy .35. I doubt that it got to 10,000 rpm with the 8x6 prop as I was running it very rich. I did not tach it but it should have enough cooling for a good break in. I ran a quart of fuel through this engine with the 8x6 prop and it appeared to be ready for a heavier load. I ran three minute runs and permitted the engine to cool between runs.

The damage was caused by switching to a 10x6 prop and running it very rich. This is when the p&c fit went away! Up until that time, the p&c had a great fit but after one very rich run on the 10x6, the p&c seal was gone. I knew that I was on shaky ground attempting to run the McCoy engine! I have been told that this will happen with a McCoy of that vintage as the cylinders were very soft! I remember as a youth seeing new McCoy engines that had two rings come from the factory with almost no compression. I had an .098 with TWO rings that would not start from new! I have a couple of McCoy Sportsman .19 and .29 engines that have never been run that have no compression. I have been tempted to send them to Mr. Bowman for rings but common sense always seems to stop me! Lol I also had a McCoy Red Head .60 that had no compression when new that I put a set of K&B .61 rings in it and it ran great with those rings.

In any case Scott, keep up the great engine rework!

Be well my friend,

Frank