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Engine basics => Engine set up tips => Topic started by: wwwarbird on October 19, 2010, 07:13:50 PM
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Between the two McCoy .35 Redheads with the shiny smooth case and the satin one with the lightning bolts, which one is better? Is there even a difference other than appearance? Which one is older/newer? I'd guess the smooth one is older.
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The lightning bolt cases do have a bronze bushing within it. The smooth case doesn't have this and it pretty much looks like steel. I've been told the lightning bolt case is generally of better quality. I can say from my experience the opposite. I own several smooth shiny case Mccoy's that run beautifully. Others wonder why they run so well but I enjoy them. I have experienced these engines wearing out in only one run even using the correct fuel. I pulled one out of a bag my dad owned since new from 1966 and it ran once and now it has no compression. I've had this happen multiple times with Mccoy 19's. My best runners are the shiny cases though. I believe the lightning bolt cases were the last run of these engines. As quality control was recognized as quite poor these were an attempt to recapture the audience. My father always said "What do you want for $4.95". The majority of fliers would buy them several at a time on the blister pack and just fly them until they died. Some of my shiny case Mccoy's have a brass button on the back of the conrod in which I traded them out for the nylon ones. What I find ironic is the fact that they improved the crank bushing while the piston still self destructed as the engine ran. When did someone actually wear out a case on a Mccoy as they never lasted long enough to do so. Ken
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The lightening bolt case is definitely better! The sintered iron pistons were the real problem. However they were supplied by the same company that made the Johnson pistons. So the idea was good, as the Johnson pistons work very well. Must have been a poorer spec by Testors that gave the trouble. It is easy to regain compression by tapping the crown of the piston with a hammer! Then just lap it back into the cylinder. This has been covered in other posts.
When they run well, with good compression, they give a super 4-2-4 break and they don't give anything away to other more modern engines. I bush my crankcases (a la Zambelli method) and usually make a new piston from good quality meehanite. It doesn't take a lot of work if you have the kit to do it and the result is extremely good, as Kenneth testifies. The Lightening bolt 40 is even better and GMA tried to buy the tooling to remake the 40. That tells me that I am in excellent company regarding the run quality of the McCoy redheads.
Regards,
Andrew.
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Hi Wayne,
Your assumption is correct, the Lightning Bolt cases were the last of the Red Heads. All seemed to share the same piston material, though. And the QC seemed to really fall off by the time the LB cases were being made. It is a crap shoot as far as whether or not a McCoy Red Head will last....... I have some that are still just fine, others that are not. All the bad ones have lost compression, big time. I have converted several .29-. 35-.40s to the dykes ring pistons from the Series 21 Testors boat anchors. So far, only the .19 will not be a direct drop in. The wrist pin is different, so reaming is necessary.
Lots of guys had the engines chromed once they lost compression and that seemed to work really well. Heating the piston enough to grow it, or tapping the crown (gently!) is a short term fix. Not the very best way to cure the problems.
GMA did say the McCoy 40 Red Head had the best stunt timing of any engine made at the time.
Big Bear
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Thanks for the info guys.
I just recieved a lightning bolt one today that I plucked off of Ebay. When I went after it, it was obvious that it had been cleaned up to sell. I rolled the dice and got it pretty cheap. It looks better than new externally. The only bummer is that the front mounting holes have been enlarged, couldn't tell that from the pictures. I hate it when people re-drill or modify the lug holes. I know it doesn't hurt anything, but to me it de-values an engine.
I haven't run it yet, but seems like it's got very little compression. I'm not bashing the seller BTW. I've learned that some guys have made their own replacement pistons for these things, does anyone sell better replacements that will last?
I also picked up a shiny case one recently that feels really good when you turn it over. I haven't had a chance to run it yet though. From what I'm hearing here and elsewhere, even if it is a good runner, I'm nervous about the compression going away in short order. I'm prepared to mix up some 10% nitro fuel with whatever castor amount would be safe. Right now I'm figuring to mix it to around 25-28% oil.
Without having any previous McCoy experience, I'm just trying to gain some confidence here. I keep thinking I want to stick to my original plan and use a period engine in my Super Combat Streak project, which I plan to start on soon. It just seems to me like a Redhead would look perfect hanging on the nose.
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Wayne,
I thought that it was common practice for the McCoys to make the front holes a bit elongated to that they could mount into other mounting holes without modification. I will look over a couple I picked up recently ($10 each with good compression) and see if what I remember is true. You can always use a bigger washer to hide the offending site.....
John
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That kind of rings a bell John, but these look like someone drilled them.
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John's right the lightning bolt cases had a slotted front hole as standard.
I think the best of the redheads are the shiny case with the plug in the center of the head (not offset) these had the best metalurgy & QC.
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John's right the lightning bolt cases had a slotted front hole as standard.
They didn't do a very nice job of it then. ;D Thanks for the info Dennis.
I forgot, what glow plugs do you guys recommend using with the McCoys?
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They didn't do a very nice job of it then. ;D Thanks for the info Dennis.
I forgot, what glow plugs do you guys recommend using with the McCoys?
Nope - not a nice job. Might have been made worse by a home mod job too.
I last flew McCoy (a 40) in 1971 - my database (& memory) is a bit suspect, I think I ran Fireball Medium range. Today I would start with a K&B 1L, or just a plain old OS sport - forget which one that is. I also ran K&B 100 fuel, (7% nitro 20% Castor) Today I would use 10% nitro & about 18% Castor/Klotz blend in both cases to keep the heat down. (I'm sure others will disagree with that tho...)
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Thanks for the info guys.
I just recieved a lightning bolt one today that I plucked off of Ebay. When I went after it, it was obvious that it had been cleaned up to sell. I rolled the dice and got it pretty cheap. It looks better than new externally. The only bummer is that the front mounting holes have been enlarged, couldn't tell that from the pictures. I hate it when people re-drill or modify the lug holes. I know it doesn't hurt anything, but to me it de-values an engine.
I haven't run it yet, but seems like it's got very little compression. I'm not bashing the seller BTW. I've learned that some guys have made their own replacement pistons for these things, does anyone sell better replacements that will last?
I also picked up a shiny case one recently that feels really good when you turn it over. I haven't had a chance to run it yet though. From what I'm hearing here and elsewhere, even if it is a good runner, I'm nervous about the compression going away in short order. I'm prepared to mix up some 10% nitro fuel with whatever castor amount would be safe. Right now I'm figuring to mix it to around 25-28% oil.
Without having any previous McCoy experience, I'm just trying to gain some confidence here. I keep thinking I want to stick to my original plan and use a period engine in my Super Combat Streak project, which I plan to start on soon. It just seems to me like a Redhead would look perfect hanging on the nose.
Wayne,
I'm finishing up a Combat streak for old times sake and using a Red head. Probably the first one I've used in 40 years. Why, you ask, simply because I have a few and I want to hear the sound of a McCoy again.As to wearing out quickly, we all bought them as kids and got a summer out of all of them. Kids aren't friendly with stuff and we really gave those engines the acid test and by the end of the summer they were pretty rough. But they all would start and run. We all used Fox super fuel and didn't worry about 4/2/4 runs. When they got lose on compression we used a shot of 40 wt oil, a prime and hit it fast and it would run the flight out.
I'm sure that you can lose compression in one run but you would have to be using some low oil,synthetic blend and get a lean run to do it.
Dennis
P.s. They never got the meticulous break in that others swear thet you have to do or it will die. We simply ran them rich for about a dozen flights.
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I agree with Dennis L., in that the McCoys were most often "used and abused" when we were young"er". I flew mine richer than everyone else, which meant I didn't get them as screaming lean as I could. And I used the highest amount of oil I could get. Fortunately, I have the very first McCoy Red Head I ever owned (a .19!) and it is still in a model that I could take out tomorrow and fly. My friend went through his in one summer. He DID run some Missle Mist in it every now and then, and used 9X8 Power Props. LL~ At $5.95 they were the closest thing we ever had to "expendable". Save all year and get a new one for the summer! LOL!!
It all depends on how you want to run it, and such. They DO have a beautiful 4-2 run, better than any other IMHO. George Aldrich DID buy out all the spare parts he could get and make a series of "McGAS" engines that are excellent. He improved everything that wore out on the originals. He also sold out of the .40s as soon as he made them! LOL!!
Big Bear