You don't want to turn the engine over to protect the piston! I have seen some verrrrry ugly stuff in some very expensive engines! The C/S-G&Z are no exception!!!! It doesen't take much of a skore in a piston to keep it from giving top performance!
Cleanliness is your engines best friend!!!!!!!!
Q/C seemes to be much improved on the G&Z! Most things can be corrected with the exception of the rear bearing bore. I have 1 of 9 that is to loose so that is a pig in a poke!
This is great news. I can stop slathering my engines in various snake oils and just use good old kerosene.
I had some correspondence last year with Pat Rose of the UK. He kept referring to parrafin, which I later found out was kerosene.
I like the way WD 40 makes engines feel, they instantly loosen up. I'm not comfortable with some of the possible long term protection characteristics, so kerosene is my new mantra. Thanks to all, please continue...
Either will work equally well. In talking with the Mgr. of the line dept. and the local airport, and having flown full scale aircraft for 15 years, their is a slight difference in the makeup of Jet A and K1. Basically for our purpose they are equal.
Though its use as an illuminant has greatly diminished, kerosene is still used extensively throughout the world in cooking and space heating and is the primary fuel for modern jet engines. When burned as a domestic fuel, kerosene must produce a flame free of smoke and odour. Standard laboratory procedures test these properties by burning the oil in special lamps. All kerosene fuels must satisfy minimum flash-point specifications (49º C, or 120º F) to limit fire hazards in storage and handling.
Jet fuels must burn cleanly and remain fluid and free from wax particles at the low temperatures experienced in high-altitude flight. The conventional freeze-point specification for commercial jet fuel is -50º C (-58º F). The fuel must also be free of any suspended water particles that might cause blockage of the fuel system with ice particles. Special-purpose military jet fuels have even more stringent specifications
John: There is a LOT of "hype" about oils out there, both after-run and lubricating (for fuels).
The worst operating conditions for model engines, are: 1) Model boats , 2) Model cars , 3) C/L speed & Racing ,R/C Helicopters & R/C Plyon racers (TIED!) The Boats STILL run Hi-Nitro, AND Full-wave Tuned Pipes. Run in Water (RUST), and have serious over-revving problems, not to mention sudden stoppage!!!! (Hydraulic lock). The cars don't run as much nitro, but are air cooled , run VERY-HIGH revs, (and Over-rev!), and are prone to dust & dirt ingestion. (Lapping compound!)
We used to run SERIOUS Nitro content, as did the R/C Pylon (F1) crowd, air cooled. but with the Nitro content we now run, you see lots fewer "LEAN- BURN DOWNS" Ditto the Pylon guys. Helicopters flyers are H-P Nuts like we are, and run as high as 30~40 % Nitro mixes, with generally poor cooling and Tuned Exhaust systems/ Mufflers. They, along with the Boat and Car guys, and the C/L Racers also run a lot longer at a time. (5~15 minutes)
I've tried WD-40, CRC, LPS, and numerous other products, but have generally used only the Marvel oils (See Clarence Lee's articles in RC Modeller) for the last 15+ years, with excellent results. The biggest corrosion problems are with the R/C crowd, with Boats being the worst, closely followed by the Helicopter & Sport R/C bunch. The MOST IMPORTANT THING is to LUBE THE ENGINE, THOUROUGHLY, AFTER RUNNING IT!!!!!!!!!!!!!!!!!
This should mean flushing it COMPLETELY, both internally, and externally! If you run the engine, AND FORGET TO RUN IT "DRY", you'll have PROBLEMS!!!! The Local Boat & Helicopter guys forget to do this and the resulting corrosion is not a pretty sight, not to mention Expen$ive!! Plus the Boats are running in a "witches Brew" they laughingly call "water", that plays HELL with any Non-Anodised aluminum and rusts the steel, bottom-end parts OVERNIGHT.
Use the following as a guideline: If you're getting corrosion on a REGULAR basis, You're NOT doing the right procedure! ASK someone who DOESN'T have the problem what they're doing differently. All of the previous suggestions in this forum will work properly, IF DONE REGULARLY & THOUROUGHLY!!!! IF YOU HAVE A PROBLEM, CORRECT IT!!
PS: there is a product known as De-odorized Kerosene available. WE used to use it in a Mfg. plant I worked in @ 30+ years ago for the same properties you're all looking for, CORROSION PROTECTION, Without the "Smell"! It should still be available, if elusive. Try your local Petroleum Distributor. I have to drive 30 miles, one way, to get "Stoddard Solvent" now. I use it as a general rinse for the hone & 1st stage cleaning. ALL of the above items, Plus fuels, paints,etc. should be used with a "Barrier Cream" to protect your skin, otherwise the repeated exposure will cause Contact Dermatitis, which starts out as "tiny water blisters" on the skin surface.
I use an Ultra-Sonic cleaner for final cleaning. You have to remember to DRY the parts, AND Lube them afterwards. If you don't have one, I STRONGLY RECOMMEND ONE!!! You should look for one with a Stainless-Steel tank. Some of them are sold in stores as " Denture or Jewelery Cleaners". DO NOT use the solution they sell, as it will darken the aluminum parts, severely! Prices are @ $30~50. Industrial ones are about a pint size and up, and cost @ $200 or more depending on the size and power. The one I have used for the last 25 years is a 1/2 Gal. Branson unit @ 100 watts power.
If you're seriously considering doing your own sleeves and pistons, A Ultra-Sonic cleaner IS A "MUST", along with a Sunnen or Superior hone, with the appropriate mandrels and stones, AND APPROIATE MEASURING DEVICE(S)!!!! I'll cover this subject on a later posting, if anyone's interested. PISTON AND CYLINDER FIT IS "THE MOST IMPORTANT THING TO GET RIGHT", in an engine!!!! All for now, Cheers, Glen
I have an engine that would be difficult to tap the crankcase in order to provide pressure for the fuel tank. The engine, a Rossi 21 (Not Novarossi) came with a tuned pipe and I was thinking about tapping the pipe to provide fuel pressure. The question is where on the pipe is the best/correct place to tap it? I want adequate pressure to pump fuel from the engine but I also think that if tapped in the wrong place you could end up creating a venturi that would actually apply negative pressure to the tank. Any suggestions? Also, I know the RC guys use muffler pressure all the time but has anyone heard of an explosion/fire caused by tapping the pipe and routing the pressure to the fuel tank?
Pilt, On my Novarossi .21 I take the pipe pressure from the maximum diameter point on the pipe. Dont use any restriction in the pressure fitting. It has always worked great in the boat (full out A hydro), better in fact than any of the other domestic engines however I attribute that to the small prop the Nova uses compared to the slower turning domestic designs. Do not be concerned about heating the fuel. Without the pressure the engine will not suck fuel sufficietly to work in the rough enviornment on the water. Arn't .21s fun! JB
Thanks for the info. I think the graph says it all - It appears that I have at least two options; Number 1 would be to put the pressure tap on the cast header/manifold directly behind the engine. The reason for this is that the header/manifold is made of cast aluminum and is thick enough to drill and tap. Number two would be to put the pressure tap at the seam that is located at the junction of the divergent and convergent sections of the pipe (the pipe material is thicker here, too). To answer the last question - Yes, 21's are fun!
Pilt, I have never seen anyone put the pressure tap on the head pipe. You are on your own there. I know it works at the conv/diver point. I glue the fitting in with filled epoxy just in front of the seam. JB
Everyone is using the press. at the major Dia. now. Rossi Bros used a press tape at the headerpipe in the '70's and then went to the major diameter I believe. On R/C engines we use muffler press. but no press is at the fitting or tank until you are at full thottle. The carb works on suction at sloww speeds and this is why the R/C carbs have such a small hole. Jon De Fries
As to the Pipe versus crankcase pressure, the difference is that the pipe pressure works and the crank pressure doesn't! On pipes only, but that was the only way we could make them work where the engine had to change speed and load. I never made crank pressure on a real piped engine work in anything. JB
How do you tune them? Do you? Do you set up the engine without it first, then add it? How do you arrive at the optimum? Do you have more than one per airplane? John S.
John: The correct (starting) lengths for a 7/8ths" Dia. Minipipe for an F-40 are: 3.4~3.6" Overall PIPE length only. The stub will add @ 5/8~1.0" to this. A 1.0" Dia. will be .2 or .3 shorter. This works well IF the Exh. timing is within reason.(ie: NOT pipe timed) I don't have any lengths for other classes at present. .21's should have 3/4~13/16" Dia. pipes. D @1.0~1-1/4" Dia. If you use a smaller Dia., it will be longer. Same for higher exhaust port. Shorter for bigger Dia. and higher rpm.
Do some test running with "unload props" that equal your "in-air" rpms, to find a starting point. Run the engine with the Exh. stub only, then with the mini pipe. This will give a starting point. Then test fly on different props/mini-pipes to find the fastest combination. The current F-40 record is with a Taipan style 8d. x 8-1/4 p." (Eichenberger?) CF prop and @ 3.3" x 1.0 dia. mini-pipe. at a relatively LOW RPM, and Cold weather. The Nelson FR engine is "stock except for boring the crank ID to .500+, and a 1.0 exhaust stub/mini-pipe.(Mine, NOT Henry,s) The only other change is to "D" mill the cyl./ fins to @ 1.5" dia. to fit in the model. This is essentially the way Bill Nusz built it. He got the engine(s) from Doug Galbreath with a "loose" fit on the AAC set-up. This gives a lot less break-in time before the engines reaches peak. A "standard" fit will need @ 15~30 minutes of flying time to reach peak. Too long a mini-pipe can hold your speed down. Too short makes it hard to get a needle setting, or the engine will "fall-off" at the end of the run. Remember, a good run lasts @ 22.5~23.5 seconds. More later, Glen
