RE: bad engines
 

I bought a new 2012 Tacoma 4x4 this summer with the 4.0l V6 and 6 spd manual xmission. It had 3 miles on it when I rolled off the lot. I got it in Georgia and thought it wouldn't get over 3000 rpm on the way home. I've never seen any engine that tight. It finally broke in right at the 5000 mile point. I was watching torque, rpms, instant fuel economy, etc with a Scan Gage.

I told my sister in law about the engine since she retired from the Kentucky plant and engines were her favorite thing. What I like about talking to her is how she tries to do everything by ear first. Anyway, she said that all engines got 90 minutes of run time on the turn tables.

That Scan Gage has paid for itself in fuel savings. I always average 3-5 mpg better when I'm watching what it says.

RE: bad engines
 

The last time I visited the Fox factory was way back in March 1978. I got to talk to Mr Fox himself and he gave me a little tour of his factory. CNC machines didn't exist much back then. But I am pretty sure they have CNC machines now though. But Fox does do a lot of government contracts too.
So they'd need them for some of the stuff they make.

I remember back in the 1960's when we all considered a engine with 69,000 miles on it as being worn out and needed to be rebuilt. Times have changed since the crappy quality control the car companies had back then. But that has changed a lot since then. Nowadays  going 200,000 miles on a car isn't a big deal anymore.

RE: bad engines
 

Yes they are.  So now they can set tolerances so that the low tolerance for the sleeve is higher and the high tolerance for the piston and ring lower.  So that no engines are as tight as many were, but no engines as loose as an OS either.</p>

RE: bad engines
 

This is interesting. Glenn Cox was able to set tolerances very precise on his engines, particularly the .049's. This is in the 1960's. Even though the piston and sleeve were steel on steel, they would break in quickly because of the precision. He could turn out engines much cheaper than the other manufacturers, leading him to have a near monopoly on .049's. It wasn't because of anti-competitive acts but simply producing a better product at a reasonable and lower price.

RE: bad engines
 

I know that this thread is supposed to be about "bad engines", but the point has been made that Cox produced some extraordinarly fine engines in the Fifties forward. I couldn't agree more. My comment about my hard starting Cox Medallion .15 reflected more on my inability to figure the Medallion .15's starting drill rather than it being a "bad engine".

In early 1960 or so, our local owners (hi, Mr. and Mrs. Bowen, R.I.P., found an old, but still NIP Cox Space Bug .049 engine in their store while taking inventory. They gave it to me.

What an engine! Our neighborhood flew a mixture of engines, mostly .049 sized and mostly Cox with a smattering of OK Cub, Wen Mac, Royal Spitfire and McCoy brands. My Cox Space Bug .049 out ran them all and did it for years on any kind of fuel it was given. One of my little brothers sold or traded it off while I was in the USAF. The little ba&*rd!


Ed Cregger

RE: bad engines
 

Ed... it must be a universal thing that once a guy leaves the nest... the belongings that stayed in the nest became the property of those remaining. I had many models hanging in our boys room, both plastic and balsa & tissue, which were gone in short order after I left.

RE: bad engines
 

If you dig around the Fox site, it says that government contracts are their big customers and have always been. Using contracts to get the machines to make their passion, which was the engines. Their use to be a club member that he had his wife worked for Fox for years under father and son. The son does not seem to have the passion for the engines but has the respect of the past. I think you would hear more from them if Duke was still around.

RE: bad engines
 

I think that years ago, many of kids of the people who worked for Fox Manufacturing had part time or summer jobs test running all of the engines made or repaired even. Like many things, if you turn your hobby into a job, that passion tends to get diminished, sometimes a lot. But I think that all of Mr Fox's kids did time on the engine test stands in the summer. But I think that anyone who was test running engines for something like 8 hours a day would tend to lose interest in them after a while. it is sort of like the auto repair mechanic who has the worst maintained car around.

RE: bad engines
 

I think there is more to it. The newer Japanese engines with fit and finish looked more polished and the engines were cheaper. Fox in contrast reflected the manufacturing philosophy from the second world war, which was to produce good enough but runs good to keep costs down. It was amazing how that liberty ships were produced in scads, faster than the enemy could sink them.

Back in the late 1980's, I bought a Fox cross scavenged .25 R/C with their newer MX carb. In contrast, its outer exterior looks rougher; one can see the swirls of the aluminum engine block caused by the pouring of aluminum. The sides of the head are not turned and polished. The engine block is not shot blasted to clean up the look like with the Enya's. The crankshaft prop threading is slightly off centered as the thread progresses further down from the start of thread. It will center a prop, but it is slightly off toward the base of the prop.

These imperfections may have been acceptable in the 1940's and 1950's, but the Japanese engines had better eye candy look to them.

Besides, isn't some of the complaints with the OS engines are caused chronic abuse through use of non-Castor oil content fuel with insufficient oil content and running too lean or with insufficient cooling (cowled engines and inadequate / poorly designed muffling devices?

RE: bad engines
 

When I started flying planes in the early 80's I bought 2 Como engines. Think they were Italian.
Got a .50 and .40. They both ran good. The sleeve and ring must have been made of pour material
because the ring and sleeve wore out very fast. I didn't even get one season of flying out of them.
I replace the ring and sleeve in one but the same thing happened in a short time.

RE: bad engines
 

That's interesting, I remember the Como's being advertised in the model mags around the 1970's until then.

I've heard similar comments regarding the Testor McCoy's, which some have stated were of softer iron/steel piston/cylinder than others like the Foxes, and earlier Duromatic McCoy's etc. If engines weren't run on sufficient Castor oil content would lose their fit and compression in short order. Then still they wore out quicker. I guess that was the cost of considering first time costs instead of life cycle costs. :D

Been enjoying these discussions, a lot of practical knowledge and advice by those who had first experiences with these engines.

RE: bad engines
 

The Red Head Testor's McCoy's perhaps, but the series 21 was durable.

RE: bad engines
 

I have flown the living snot out of McCoy red and blue head engines without a single problem or premature wearing out. The secret was to keep it rich, use castor oil fuel and don't try to prop it for every last rpm. It was designed for control line stunt, which mostly operates in a lean four-stroke phase. Run it lean and it will die prematurely.

Oh, and don't expect much compression. None of my McCoy engines (all painted head) had really good compression when compared to other non stunt type engines.


Ed Cregger

RE: bad engines
 

Ed, thanks for clarification. It's been somewhat tough sorting out the wheat from the chafe. The Ringmaster's Brotherhood's advice has followed along with yours also. I've got 2 Testors engines, the .19 Red Head and .40 Black Head. I've targeted the .19 for a 33" span Midwest P-40 Profile CL, except to make up for the bit of extra power and weight, plan to extend the wing an additional 2 rib widths giving it a 38" span. There's enough material in the kit, the leading and trailing edges are long enough to do this so it is an easy mod.

Bought a used MVVS diesel engine from a man in Czechoslovakia. Paid $31 dollars for it. Throttle control is great. Has a real low idle at 3,620. At full throttle it turns 12,700 spinning a 7" by 4" A.P.C. prop. Am using Davis diesel fuel. I'm gonna start mixing my own fuel. This Davis fuel is great but it costs $13 dollars a quart ! Did some modifications to an O.S. Max .10 muffler. Mounted this muffler to my diesel. I now have a nice QUIET diesel I can run at the club flying field.

JP, a lot of guys would find this interesting in the Everything Diesel forum. Thanks, Dave

GHQs??

What I _do_ have experience with was CS engines. These were ROUGH, looks like they were put together by someone using a file, a hand drill and other hand tools. The prop nut is SUPPOSED to be 1/4-20 like most engines that size BUT the threads on the crank were cut with a weirdly-calibrated lathe so regular storebought nuts wouldn't fit. The port in the crank was ROUND so the induction timing was radical even though the intake was restricted.

Iskandar

You know, after reading this:

http://modelenginenews.org/ad/deezil.html

I've come to realize how LUCKY we are to have the excellent engines we have today.

Iskandar

Crankshaft thread size and pitch.
 

Hi:

I think that you meant the the crankshafts are threaded 1/4-28! If you are looking for a 1/4-20 thread, good luck! Lol

Be well,

Franchi

The last Fox motor I bought was a lemon. I grew up in the 60's running fox 15's and 35 CL motors. When I went to RC I used their 15s,25s, 40s and so forth. The last one was a 45 with the crappy flange mount carb. Lost 2 planes on constant flame outs. Over the years I have run just about all makes, including the infamouse GMS motors and could get all of them to transition well. So I sent it back to Fox, who said the carb was bad, replaced it, test ran it and set it up and even included a nice, signed test sheet with rpms and prop size recorded. Sure enough, constant flame outs. Sent it back again, at which point they said they did not have the parts to repair it and offered to give me 50% off on a new one, the same deal they would give someone who sent in a $5 swap meet used motor. Not great service on a motor that gave me a total of 2 flights without problems. So have to agree, not the same company as when Duke was alive. Especially when there are so many motors out there with great service records to choose from.

Now you have a collector's item that in all its roughness can make money on E-Bay! ;)

Barry, your Tokyoty example is like a lot of the engine examples stated here, many engines listed as bad here have served others well. My neighbor just got rid of a 2011 Toyota Tacoma because it had awful piston slap that would rival a Mack 711.. He took it to Toyota in Fredericksburg several times and they said it was normal. He traded it in on a 2013 Tacoma. MVVS happen to be one of the best you could buy.

At the control line contest in Dallas last week end, a friend and I were talking. He commented that when he heard someone at the flying field not happy with their engine, he would offer them $2.00 for it. He said he collected a few engines this way, and would fool with them until they worked to suit him.

I guess it just depended on what was truly wrong with them. Sometimes, it can be as simple as a gasketed surface or plug leaking. Sometimes just a good cleaning and sealing. I got what seemed to be a weak Testor McCoy .35 Red Head. With some prodding from Dennis in the Brotherhood of the Ring Forum, After further examination, was losing compression from the head joint. I took it apart, thoroughly cleaned. Found excessive vibration from a bent prop shaft on the crankshaft. After straightening with some pounding by strategic hammering with a pin punch, straightened it. Now it runs fine. ;)

But I have a few engines I picked up that were abused in their prior life by running overly lean and possibly with the wrong fuel. The piston's metallurgy was ruined, too loose from scraping the cylinder walls with insufficient lubrication. Those required replacement cylinder and piston or became donor engines with the other good parts. :p

Speaking of bad engines, how about bad engine mounts. I salvaged this one, A Dave Brown or Kraft 15-19 one, by filling the unneeded holes with a JB Weld generic equivalent, then filing off the excess, cleaned up with plastic cleaner/polish. This is for an Enya .09-III TV.