FlyerInOKC

My Feedback: (6)

Petromat® | Nilex | Geotextile Materials, Erosion Control & Retaining Walls for Construction Projects

Glowgeek

Thanks, I'll try some spearment'n with a 14% oil instead of the 17.5% I've been running.

Bruce, your needling comment seems backwards to me. With less oil and more combustible fuel available it seems to me that would make the needles more sensitive per click ie courser.

Jesse Open

Fabric:
Do shop around! I advised our fabric runway contingency to get a few more prices and check with local excavators. We saved quite a bit of cash and actually found a local source and saved shipping.

https://www.bing.com/search?q=fabric...ZI&form=MOZTSB

Regarding the oil, much as Acdii described. Additionally, I would not be doing 14% oil with straight synthetic. I still intend to try out 12% oil but the portion of castor will go up to compensate. IE: 4% castor and 8% refer slime oil.

The added oil is non-compressible so it does affect the functional C/R by raising it proportionally as oil goes up. The less viscous fuel also draws more easily.

Glowgeek

Yes, I intend to keep the castor content at 2.5% in the 14% total oil package.

Good point about the lower viscosity with less oil. Another reason why needling would be more sensitive.

acdii

I thought that is what I said, finer tuning, IE More sensitive. Just like a 6 pack carb setup without the vacuum gauge.

Jesse Open

Glowgeek

Pete, Gary, can either of you quanitify the performance gains you saw when moving down to 14% oil? I'm curious.

What if a fella opened up the ring end gap .0005"-.001" to allow for more blowby? Certainly more oil would be present in the case. If the power gain from running less oil exceeded the power loss from the wider end gap we would have a win-win. Of course there's always the option to raise the c/r to compensate for losses too. Might even allow the use of 10% oil with no negative side affects?

acdii

Now that I think about it, I think the main reason glow fuel has more oil content is due to the Methanol having cleaning properties verse gas having lubricating properties. Pump gas has lubrication in it for fuel injectors, and Methanol is good for degreasing. It is also well known for absorbing moisture, so more oil may be to compensate for those factors.

Glowgeek

Yes, but primarily the lack of roller bearings on the con rod ends.

acdii

The FG engines don't have needle bearings either. They are basically a glow engine with a Walbro and spark plug.

Glowgeek

The FG 21 uses a 20:1 gas to oil mix, what the heck? Is there that much lubricity in gas?

acdii

Gasoline is a complicated substance. I don't know off hand what the actual "gas" content is, but what comes out of the pump today is nothing like what was used a long time ago. There are so many different additives, and mixes to Gasoline today that it really can't be called that. You know those Coleman lanterns that use White Gas? That is what real gasoline is, AKA Naptha. Lead was added to it to prevent knocking, and that is pretty much what was used in cars. Today it is blended with benzine, toluene, and a host of other distillates along with lubricants and detergents to clean and protect the fuel injectors. Gas is produced from oil, so it naturally has some lubrication to it.

OTOH Methanol if produced from natural gas or fermentation and distilled like Everclear, which makes a great cleaning agent. It is also hygroscopic and absorbs moisture, which is not good for engines. This more than likely is the main reason for the high oil content.

Glowgeek

Thanks Bruce.

acdii

Who's Bruce?

FlyerInOKC

My Feedback: (6)

The former owner of my LHS did some experimenting and he found several 2 cycle glow engines that would run on a gas/oil mixture with a OS gasoline plug.

FlyerInOKC

My Feedback: (6)

You forgot the cold weather additive to maintain the octane level when the temperature dropped.

acdii

In today's gas, the winter blend is actually higher benzine content and other volatiles that evaporate too quickly in warm weather, basically junk that has no other purpose other than to be burned. Additive packages vary by where the fuel is being delivered to. Top Tier gas uses the same base as all the rest, it is the additive packages that make or break the fuel. As long as it meets the minimum octane levels, they can add whatever the want, or not want to add. I can always tell when the fuel has been switched to winter blend, the smell of benzine is quite apparent. What's interesting is that BP, Mobil, Shell all have he same base stock as Costco, Sams, and Walmart, but the additive packages are what sets them apart from each other. What is in Mobil Supreme+ is not the same as what is in BP Ultimate, or Shell V-Power Nitro+. In some cases you actually do get what you pay for. I try to use Ethanol free Premium in my RC engines when I can. It stores longer, and runs better, and I don't have to worry if I don't drain the tank.

Jesse Open

Glowgeek

Interesting, srtelemaster (Dan) has a thread on ring gaps and lubriction where he found stock Saito ring gaps as wide as .012". That seems excessive to me and that engine must have shot a lot of oil out the case vent tube. When he replaced that ring with a bowman gapped at .002" there was still plenty of oil left in the case after a run. Good to know but it's not an indicator of the total amount of oil run through the case per ounce of fuel used.

I have an extra ring for my 82. I'm considering catching the oil from the vent with a standard gapped ring (.0015) and one file gapped to .004" to see the difference in oiling and performance.

the Wasp

My Feedback: (1)

don't forget the rod to pin oiling, and rod to wrist pin oiling.
when ever I take an engine apart I hit the rod with the old trick we did with our glow boat racing engines. that is to take a drill with about twice the diameter of the oiling hole in the rod and put a short taper on the hole, this to help drive more oil to the bearing. but of course Saitos do not have rod bearings, but never the less it will work on Saito rods too. I would think this would be helpful to the Saitos if you mix with a lower oil percentage

Jim

Rudolph Hart

Bruce...that's YOU do you remember a few years ago we were all using first names here except YOU. I found your ACDII a bit to roman numeralish for me so i shortened you to ACDC, good old aussie rock and roll band and no harm in that i thought. Then a mate down here said that could also refer to someone who may be a bit light on the loafers, so then i just started calling you bruce cos down here that's what you do when you can't remember a persons name, and as i said back then if you don't come up with your real name your stuck with it.

Lonnie i did'nt record rpm when playing with the oil ratio. Eventually settled on 12% klotz syn and 3% degummed virgin castor oil. I got a slightly nicer idle.

Rudolph Hart

Since we've been talking props...here's one i've always wanted to make

FlyerInOKC

My Feedback: (6)

That would drive someone batty!

acdii

Well, if you insist

Took a selfie for you

FlyerInOKC

My Feedback: (6)

You wish!