blkbird68

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I am not holding you accountable for anything the guy told you...just trying to point out that he may not have given you correct info.

In my experience H1R doesn't burn any cleaner than MC1

Slyder

rc bugman

My Feedback: (30)

Capt,

air temperature:

I tried to load the engine to force the engine temperature into the 200-220 degree range. The 3W manual states that bad things start to happen once the engine temperature exceeds 230 degrees (oil breaks down and does not lubricate, engine components start stretching ect). I accomplished this by running a prop which was too large, engine was anchored so the prop never unloaded and the engine ran full throttle for 6 straight hours. If I ran these tests when it was 70 degrees, I would have to adjust the prop load to maintain the temperatures at 200-220 so I don't think the outside temperature affected the carbon buildup. However, I was unable to completely duplicate the same temperature range between oils. This injects some level of variability in the comparison between oils.

Since I am extremely busy once spring arrives and that level of activity does not drop until September, this test would not have been run at any other time of the year. If neighbors' windows were open during these engine runs, I would have had complaints on day 1.

Marine oils:

I included this oil as a comparison. These oils are suppose to carbon up air cooled engines because the engine temperatures are too high. This oil did produce a lot of carbon but it deposited it in the muffler rather than in the engine.

Gasoline:

I used Mobil 93 octane, modified for sale in upstate NY during the winter months. Gasoline is blended different depending on season and location in the country

Elson

Flypaper 2

I wonder where 3W is measuring their temp. Aircooled engines run at 300 to350 F under the plug, for optimum temp. Temp makes a big difference on carbon buildup. When I ran a Small engine shop, a customer with a Lawnboy would run at half throttle with little load,aka, short grass for the summer season. Ex ports would be plugged solid with an 1/8 hole in the centre for the ex. to get out. Ran nice and quiet! Next guy would have the same mower running full throttle, cutting long grass, in other words , fully loaded. Tan brown carbon on piston and top of cyl, and circumference of ex port, in other words, proper temp. The lines across where the int comes in is where the raw fuel, and air velocity washes the carbon from the piston, somewhat like a pressure washer.

pe reivers

I have been lurking around both threads al along, and very much appreciate what has been done.
Great work Elson and Ken.

I believe, that in the presence of hydrocarbons, carbon build up originates from twe sources. Engine surface heat, and condensation of combustion by-products, in various ratios to one another. These two sources interact, so maybe it boils down to there being only one: combustion by-products.

An incomplete combustion process, as near to the metal surfaces or in a partly loaded engine produces a lot of soot, that eventually clings to all surfaces it contacts. Hence the port and exhaust blocking in lightly loaded garden appliances. Using mineral Castrol TT oil, I also experienced quite heavy deposits in a Motocross engine, which are not so highly loaded as one might think.
Carbon also builds up on the inside top surface of the piston, more so with a hotter piston. Here the more volatile hydrocarbons evaporate, leaving the heavier non-volatile high carbon fractions behind. This same process also applies in the oil aerosol present in the combustion gas masses.
A combination of these two processes produce the carbon deposits we notice, and try to interpret. This intention may be a dead end.

Whilst low carbon deposit operation is very nice, IMHO, it has nothing to do with one of the main functions of oil, being slippery and prevent wear. In that respect, I found all oils tested OK, except Amsoil at 1:100, where piston scuffing became evident. This oil content definitely was too low.
For very low carbon formation, my choice would be the Bellray. However, I feel uneasy about the lack of specification reference. It seems a very clever concoction develloped for a couple of racing engines, probably by a long series of trial and error, so there was no budget left to perform the tedious task of oil classification testing.
In regard to the leaner mixture: I vaguely remember a Bellray publication some time ago, where they warned for a viscosity increase which required jetting to higher orifice values. For a racing mechanic this different jetting is no big deal. I remember jetting our MX engines for moisture content and ambient temperatures. The jet difference being up to three points between cold and damp, and hot and brooding. One glance for the presence of jets in the box of the competition's mechanic would tell me if they were serious contenders that would make it to the checquered flag.

rc bugman

My Feedback: (30)

Pe,

Thanks for the explanation. It sheds a lot of light on the pictures and data.

Elson

rmh

After looking at all the pictures -one thing appers as evident --at least to me -
The heat soak -in the pistons is too high on most of the test setups .
This problem will change from engine to engine - simply because the UNDER PISTON HEAD flow is differet in different brands.
Doubt it?
look at the pictures-
carbon forms hard on hot spots.
My own use of gas engines is not anything like the long test cycles noted by Elson .
The engines run at lower rpms for most of the flight -then are bumped to full power ONLY as required.
This cyclic power use- allows the piston to cool .
My own oil tests stopped , when I found a combo which produced no carbon -None- plus no scuffing - none- operated in this fashion.
Prior to the 32-1 all syn setups -I got some hard carbon and some scuffing - and we have a number of engines all flown in same fashion- (IMAC Unlimited and Advanced class flyers -using tuned systems and or can mufflers .)by me as well as others in the area.
I rev my engines from static loaded 6500 -7800 on ZDZ to well into 9000 on the ROTOS - on full power bursts .
My idea of best oil is one which works best under this type use.
If I was running an engine fully loaded for long periods -I would rethink the entire thing .
When we drag raced ( Chev V8 engines )- our interest was for best performance at full bore for only a few seconds -
This is totally different than running flat out on a oval track -
So make your own tests and choices based on your own use .
I once adapted a 265 Chev from a Crackerbox race boat -into a Austin Healey- for a killer street racer setup. (2100 lbs)
The clearances for the flat out boat race setup plus cam/carbs (6)- etc--was all wrong for the street - tho that setup was really quick - it was a classic case of "the wrong setup for the job".

RTK

My Feedback: (1)

If anybody has some free time they can read this article. You only really need to look at the first 2 tables and read a couple of paragraphs.

http://www.ultralighthomepage.com/OIL/oil.html

lsnover

My Feedback: (19)

Dick:

Maybe you've answered this already, but I'll ask anyway.

What oil and mixture are you currently having the most success with?

Regards,
Lee Snover

captinjohn

RTK Thanks for the link....it is very imformitive. I sure want to use good oil in my engines. What do you think of oil additives like Slick 50 to the crankcase of our model 4 stroke engines? It may (I think) give more RPM and give more logevity to our engines. I have a Kavan twin I am going to add slick 50 into it. Oher engines may include.... any small 4 stroke like the small 30cc Honda , Ryobi , Sthil, Fuji, and there are a few others. Even the OS MAX , YS, ThunderTiger and Magnum 4 strokes may benifit. I am going to try some. that is my next experiment. Thanks to aLL for any and all good ideas. Sharing is GOOD Capt,n

Big_Bird

My Feedback: (1)

captainjohn, Slick 50 contains PTFE. When I was many years younger and a lot dumber a guy at a flyin suggested that I run a little of this stuff through my engine (G-38) and I would be amazed at the improvement in rpm. So I added probably about 1/2 oz to 15 oz of fuel. The engine didn't make it through the tank before it died. This stuff clogged the carb so bad that I had to buy a new one. You might could add it to the air intake with an eye dropper while the engine is running. I really doubt that you will see any improvement in the 4 stroke engines that you are talking about.

Look at this link on this subject:

http://skepdic.com/slick50.html

Ken

pe reivers

Elson, I saw your mail, but prefer to respond here.
I also have read the Ultralight story, and a lot more on different oils for different engines.
Being an MVVS distributer, I do not in standard practice deviate from factory advice, which is Mobil mx2t.
I lubricate 1:33, and am quite happy with it, though some carbon is evident. The engine feels good however, cold engines are not sticky, and the wear signature is excellent. Other TC+ class synthetics do as well or maybe better I think, and in fact, the factory approved of some.
As Dick already pointed out, the piston in our application is allowed to cool down before it gets too hot, which is much like motocross, or oval racing where each lap throttle is reduced a couple of times. Lately, these engines are all watercooled, to keep liner and head temperatures down. In Imac the use is the ather way 'round with full throttle every now and then.
I like to haul sailplanes using props that moderately load the engine. Because I need pull, I use the largest prop that allows the engine to spin well above the high torque peak, and well below max power output rpm. The longest full power application is about 1'30" after which the engine idles in glide down and waiting times.
When pulling the net, Elson on the other hand will need to apply full power for extended periods, much like a boat engine, but without the watercooling facility. My best guess would be to baffle the engine for best cooling, and still select all synthetic aero oil to top specification like Rotax suggests. The added corrosion protection of outboard oil is not needed and might generate additional ash that we can do without.
I find 1 : 50 quite lean though, and prefer 1:33 to 1: 40. Having said that, the extended 30 minutes full power runs of course also provide a continuous full flow of fresh oil, so 1:50 might not be so bad after all in Elson's application. More oil will flow through his engine in 30 minutes, than through mine in a day's work. It also happens to be the normal mix that Mobil advocates for their oil when running in is completed. Not advertising here, just repeating what is stated on the can.

captinjohn

BIG BIRD: In my post I talked about adding Slick 50 into 4 stroke in crankcase,s. I would never add it to fuel. In reading about it I never read that it was to put in fuel mix. But added to a crankcase is still a good idea in my opinion. I think the engine should be broken in first. This additive is slippery and adding it to soon will add too much time for break in I presume. This was one of the few additives ever aproved for Full scale engine use. I will let you know what happens this summer when I try it. I am guessing the engine is going to idle faster after i add Slick 50. I will have the idle stop set to a certain RPM and not touch the mix needles....add slick 50 and re-check RPM. Best regards Capt,n

Big_Bird

My Feedback: (1)

My mistake captainjohn, I didn't realize that some of the engines you mentioned (OS Max, YS, ThunderTiger and Magnum 4 strokes) had separate crank case oil. I thought the bearings were lubricated by oil in the fuel.

This is so far off the topic that we probably should not hi-jack this thread by discussing the merits of Slick 50. Let us know how much improvement you get on a new thread this summer.

Ken

captinjohn

Big Bird...I argree with you...a thread for Slick 50 would make some interesting reading. Here is my 4 Stroke engine Capt,n

rmh

You guys have GOT to be kiddin---
Slick 50 should be added only --to the anthology of Urban Legends
Put it next to the guy who got a new Chev -which got 75 mpg - and called GM to thank them .
Next morning he found the carburetor gone from his car!
Insurance bought him a replacement - but strangly -it was not the same as the earlier one .
no one at GM knew anything about what he was saying when he called them - the new carb only got 20 mpg.
It must be true, Dan Rather told the story---------

Antique

My Feedback: (4)

About 40 years ago the story was a Buick that got 55 mpg...
ALL model airplane 4 strokes are lubricated by oil in the fuel with the exception of the Kavan 50 that captinjohn has.....It has a crankcase with about 3 oz of oil in it...Another additive is Metalon, sold by B&B and Quadra..Approved for full size..Tried some in our K&B .40s about 30 years ago, made no difference at all...
There was some other stuff on RC Online (?) years ago too, forgot what it was called..You dripped it in the intake while the engine was running..It didn't work either...
Ranks right up there with putting mothballs in your gas tank

rmh

Ol Duke Fox sold a mix called "Lustrox"-(Ithink) whichyou put -just a dab in the intake to break in one of his precision fit engines --One of the locals back in Cincinnati, had a OS30 which was way too tight - I told him to get the stuff - add one tiny dab -once - to the intake .
Next time I saw him -the engine had almost zero dry compression.
He said he coldn't see how one tiny dab could do anything so he fed about a spoonful thru it --

Every time I think obout "secret & miracle" additives -This one pops back in my head.

BBW Walt

My Feedback: (11)

The old time "real mechanics" were able to add baking soda to the crankcase which offered enough abrasive to reseat the rings on you ole" oil burner, and polish the crank at the same time. Where did all these wizzards go. JC whittneys of course.

pe reivers

yep, and we also added sulphur flour as additive to prevent scoring and binding.
These are times long gone, but not forgotten.

rmh

JC Whitney-- seat covers 19.95 - exhaust cut out -wolf whistle horn - etc..
I poured over those catalogues

BBW Walt

My Feedback: (11)

It was quite an experience to visit this place. It was actually Warshawski's on one door and JC whitney's through the other. Ripley's believe it or not had to come from this place...

Antique

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Bon Ami through the carb to seat the rings fast

pe reivers

is this thread going pots?[&:]

RTK

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Also re-seats old worn out rings in old worn out tractors.