mike early

Yes, when the piston is going up, it creates a vacuum in the crank case. But the net result is pressure. Each stroke creates more pressure than vacuum.

linkadrip

i connected a pressure Gauge to the Crankcase nipple on my .72 GK Saito engine today, was curious about it and it does fluctuate. sucks and blows. turning it over buy hand the needle would go to negative pressure vaccum and then to Positive pressure. So connecting it to the muffler i would think is a bad idea. The muffler would be pressurizing the crank case and may blow seals out in the engine.

Now if you want a PCV Valve like on a car and your inventive and want to burn that excess oil you would Connect it to the intake manifold just like a car. That is what the pcv Valve in car is for reburning the crancase blowbuy vapors. But it would have to have a check valve just like a car. Look up PCV Valve for more information on this. the new OS 4 stroke Engines reburn the crancase vapors from what i have heard, havent read up on it.

Best thing to do is just vent it to a tank with a vent on the tank if you want to catch all the excess oil. or just vent it to the outside of the plane and after flying wipe the plane off like i do. Keeps my front wheel on my trainer nice and lubricated.

But connecting it the the muffler would be asking for trouble dont do it.

Michaelh

My Feedback: (4)

Yep good ball link lube also.

jb86

My Feedback: (8)

use saito, hangar 9 (four stroke), os type F or YS plug. i have ruined plugs from using too much ARO. pull the plug, stick an igniter on it, turns orange, but i guess not hot enough. new plug, runs fine. maybe clean w/denatured alcohol.
jon

jb86

My Feedback: (8)

while discussing fuel lines, how about the tank? i have heard it said, the brass tubes going into the tank can rot from alcohol fuel, requiring replacement every so often. even though the tank looks good, open it up, be sure it, the p/u and lines are all good. go thru all the lines.

orcrest

On the Magnum 1.20 they run a line from the crankcase vent back to a nipple on the carb manifold and it seems to run fine with this setup.

Cheers

Da Orc

w8ye

My Feedback: (16)

The brass fuel lines seem to become brittle from vibration as much as anything.

I've also used aluminum and copper. They didn't seem to fair any better. There are also rigid plastic fuel lines but I would be afraid to say they were any better than brass.

J.Paul Saure

Is it me or the single and twin sounds are mismatched here????
http://www.horizonhobby.com/Articles...ArticleID=1706

Saludos,
Paul

mike early

You make too many assumptions here and ignore events occuring when the engine is running vs turning it over by hand.

w8ye

My Feedback: (16)

Yes he mixed the engines all up. Use your ear and sort them out. I sent them a Email last fall but they never changed it.

SigMan

My Feedback: (21)

yep that prolly is a bad idea. mite try it on the test stand with one of my older engines just to see what happens. thanks linkadrip.(how did you come up with the name linkadrip?) just curious.

Michaelh

My Feedback: (4)

You could be safe and use the seperate check valve system for the breather. Just have to tap in another tap, like we discussed before and just simply hook up to the exhaust with no worries. Could even run a breather filter then

alpal

I am running a 300twin sigle carb in a Fw190 1:5 scale and it fits right in with the exhaust just where it should be! I bought the twin second hand and have always had a bit of a fight with the front cylinder. (it is slightly forward of the other (left) with carb facing up. The engine starts easily but often this cylinder does not fire at idle, just spits fuel. Latley this is worse and I found compression less in that cylinder so stripped it to find a fair amount of coke deposit with the result that the exhaust valve in particular, does not seat in a nice shiny ring.
Now I have searched this thread (very long thread!) and I came across the warning that the aluminium head is chrome plated and not to lapp the valve ....but how to get the coke off??
I soaked in petrol (gas to our friends in the US) overnight and it doesn't seem any easier to remove!! Bill, give me a hint old chap, ther's a good fellow!
I assume this was the reason I had trouble getting the motor to run properly, in that it idled fine and even ran 7500rpm 20x 10 but throttling up in the middle would die, with a sucking sound....
Please help, Alex

linkadrip

Well i have been an Automitive mechanic for over 20 years and When to Spartrtan Aeronautical School and have worked on lycomings and other aircraft engine's. this is a 4 stroke engine Just like a car or in a cessna. I don't see it operating any differnet. and if you connect the muffle up to that crankcase and put pressure into That crankcase you are going to blow the seals out in it period.
If the crankcase pressures were greater then the muffler pressure then i could see it working. You can connect a manifold pressure guage to that nipple when it is runnning and it still flucuates just alot faster basically . connect the same pressure gauge to the muffler and see the difference the muffler pressure is way higher then that crankcase.
The smog system on cars reburns the Crankcase blowbuy vapors through a valve called the PCV Valve witch is connected to the intake manifold. the PCV Valve has a check ball in it that ratttles back and forth basically a check valve. that gets carboned up from time to time and has to be cleaned periodiacly with carb cleaner when the valve stops rattling.
The older cars like my 57 thunderbird that has a 312 in it Has a Down draft tube that comes out of the crankcase and goes straight out and down toward the ground. Watch a tractor pull sometime. and you will see the crankcase venting happening under the engine From the the draft tube looks like steam coming out on the engine. Older cars just vented there crankcase vapor to the open air ther was no smog.
Only point i'm trying to make is i would hate to see someone take there perfectly good Saito that is working perfectly fine and hook the muffler up and blow the seals and gaskets out of it possably damage the engine. just to get rid of the little bit of excess waste oil coming out of the engine. So the plane gets a little oilly. Get an OS if you dont like the excess oil the new one reburn the crankcase vapors form what i have heard.
I dont like them i think there Ugly Engines may run good and be less messy but there Ugly I'll put up with the little oily mess but that my Personal prefrence others may vary.
The key thing is if it aint broke then why go and try and fix it.

Sigman
Well the name linkadrip was made up along time ago. I used to play alot of MMORPG games. Friends and i would sit around and make up names to use in the games. Linkadrip was just one that was thought up and seems unique.

Hobbsy

My Feedback: (102)

Link, in this case concerning Saitos, you could say, don't break it if it ain't broke. They work perfectly they way they are and they're designed to work that way, as you just said.

NM2K

My Feedback: (14)

Another misconception to nip in the bud here and now is the idea that our glow engines, whether two or four-stroke, "burn" their oil. If you are burning oil in a glow engine, you are destroying the engine by operating it too lean/hot. You can run that expelled oil through the engine until hell freezes over and it will not burn if the engine is properly adjusted.

It is very easy to confuse our glow engines with conventional spark ignition engines that burn petroleum fuels. They operate similarly, but the fuels used and the attendant oils require a rethinking of many of the old automotive cliches.


Ed Cregger

rlmcnii

My Feedback: (3)

EC,

I think you are correct in asserting that our glow engines do not burn their lubricating oil. If they did, there would not be much lubricating going on. And, more importantly, this fact renders all this talk of recirculating the exhaust rather moot. In these engines the oil must get out (some place) as quickly as it goes in. Does not matter if it goes around the seals, out the crankcase vent, or out the exhaust. It must come out.

So, just what is the benefit of sending the crankcase effluent back through the engine??

Hobbsy, w8ye, Linkadrip, and others seem to be correct also. As Hobbsy said, "if it ain't broke, don't break it."

My personal experience (just one person's[not an expert] experience)is that when properly tuned, Saitos are not overly messy engines. I have never seen any glow engine run without putting out oil (as they don't consume it) and the Saitos are much cleaner-running than many of th

mbrennan1

I need some advise. I recently bought a used Dave Patrick Ultimate with a Saito 180. Beautiful plane. My problem is that my starter won't start the motor. I have a Magnum Torque drive starter that starts all my other Saito's with no problem. My collection consists of 2-82's, a 91S, a 125, a 150, and now the 180. The 180 is well broken in. There are a lot of starters on the market and don't know which would be a good selection. I would rather stay with a 12v and stay away from a 24v. My shoulders have a hard time carrying around the extra battery weight.
I have been following this forum for quite a while now and have learned a lot. Thanks!!!!!!!!

Mike

w8ye

My Feedback: (16)

A bigger battery may be what you need though

There is only so much power available from a battery no matter what starter you have attached to it.

Michaelh

My Feedback: (4)

I have a little cheap Tower 180 starter that when hooked up to my big battery turns the 180 over very good.

w8ye

My Feedback: (16)

I was at the flying field and a friend had a Zenoah G38 gas engine he was trying to start with the same 180 starter mentioned above. The guy had two small 12 volt motorcycle batteries hooked in series for 24 volts. The starter would not turn the G38 over.

Finally he positioned his new Ford F150 truck close to the plane and hooked the starter to the 12 volt truck battery with the truck engine running.

The starter whipped the G38 around perfectly and started it right up. The battery was a big one like 75 amp hr and with the truck engine running the voltage was close to 13.8 volts.

mike early

Unlike car engines, Saitos do not have an oil pump and reservoirs.
Unlike your car engine, Saitos are designed with more ring gap than needed....for 1 reason: To allow oil into the bottom engine. How? Blow-by by design. The blowby in your car engine is an undesired effect. If you could avoid it completely you most certainly would.

How much pressure do you think is needed to blow all these seals you keep mentioning?
How much pressure do you think is created by blowby?
How much pressure do you think is created with a nipple on the exhaust?

mike early

The worst thing about the internet is someone preaching gospel and is quite incorrect.

and then someone reading it, believing it, and then preaching it themselves.

Why does it have to be this way?

w8ye

My Feedback: (16)

There's a lot of print in books, TV, and magazines that is not correct either.

You should collect all the information you can and then decide for yourself.

Michaelh

My Feedback: (4)

I will admit the battery I use is not kind on my back, 90ah .