4 Stroke Crankcase Vent
 

I have a Saito 150 that has the crankcase vent exiting under the cowl...i think i read in RCU that it is possible to route the crankcase vent tube and strap it to the muffler..... if i were to strap it with a plastic tie, would it hold up to the heat of the muffler?

RE: 4 Stroke Crankcase Vent
 

I would have more doubt about the plastic tie wrap around the muffler than the silicon rubber fuel tubing. It is after all the same stuff we use as header couplers for tuned pipes.

But I have a hard time visulizing the need to tie wrap the case drain to the muffler in the first place.

John

RE: 4 Stroke Crankcase Vent
 

why not route it back into the tank?

RE: 4 Stroke Crankcase Vent
 

i know it sounds like a weird idea, but the crank case vent is creating a mess to the belly of my plane when i come to cleaning...lots of debris to clean


you gave me an idea ... i think ill bend a piece of copper tubing and make a ring out of silicone fuel line

RE: 4 Stroke Crankcase Vent
 

id be scared that it would put more oil into my tank or mess with the tuning

RE: 4 Stroke Crankcase Vent
 

The vent line in your photo is way to long.
It should only be about 4" so it can vent.
It needs to breath in as well as out.
The way you have it it will fill up with that oily crud and move back and forth in the tube and never make it out.
Also it needs to vent to air, never run it back to the tank.

[link]http://saito-engines.info/new_engine_prep__.html[/link]

Tw

RE: 4 Stroke Crankcase Vent
 

I route my vent line back to the intake of the carb. All that is vented back is unburned oil, which is reused and blown out the muffler.
To me, it seems to improve milage on fuel and more lubrication.

RE: 4 Stroke Crankcase Vent
 

Zip tie is fine. All my Saito vents are zip tied to the muffler the same way. No problems yet. The muffler gets hot but it doesn't seem hot enough to melt my zip ties. I am usung a heavy duty zip tie not one of those dinky ones.

RE: 4 Stroke Crankcase Vent
 

i trimmed the vent line down to 5 inches and strapped it to muffler.....if it doesnt work out ill keep you all posted

RE: 4 Stroke Crankcase Vent
 

so you use a T fitting and run the vent line back into the same line that dilivers fuel to the engine?

RE: 4 Stroke Crankcase Vent
 

I have for many years tapped the intake pipe on both Saito and my OS ENGINES for a 6-32 nipple. then route the crankcase vent into the nipple. gets rid of the mess and does not have any ill effects on the motor operation.

Bruce

RE: 4 Stroke Crankcase Vent
 

No I do not use a T fitting. I take a piece of fuel line, cut it and cut a piece of tubing to fit into the vent line. Then I route that back to the carb inlet with a little bending etc, but just above the intake. It works great,, I strap that line to the motor mount with a couple of zip ties. I get a lot more fuel milage with a tank, about 3-4 minutes, and all the oil expelled is consumed back to the engine for lubrication. It works. If you just vent it out with a fuel line, it's wasted oil that can be used. The engines run perfect that I have done this on many engines, no needle valve mods or adjustments at all, except for frigid temps. I have not used a temp gauge on the head, but if they purrr, I don't need to. You know if it overheats.

RE: 4 Stroke Crankcase Vent
 

Tell that the the OS engineers! The surpass 2 models route the crankvent back into the intake manifold. The new FS-a reuse the crankcase oil through the valve head (internal). So maybe your statement is Satio only??? http://www.rcuniverse.com/forum/js/f...n/confused.gif

RE: 4 Stroke Crankcase Vent
 

This whole thing of reusing the oil from the crankcase vent makes no sense to me. Any oil that has already been through the engine and the cumbustion process is going to contain microscopic metal particles and other contaminents. Especially on a 4 stroke since it goes directly into the combustion chamber before lubing the bottom end. Once it is in that vent tube I don't want it anywhere near the inside of my engine.-BW

RE: 4 Stroke Crankcase Vent
 

I normally put a hole in the bottom of the cowl, or bottom of the fuselage, stick a rubber RATSHACK grommet in the hole to cushion the tubing and route the vent tube out this way.

You can easily put the tubing in via the grommet, and it holds the tubing in place during flights.

If you need to remove the tank, cowl, etc. the tubing slides right out.

No mess nor fuss.

RE: 4 Stroke Crankcase Vent
 

This was always my thinking too when OS started doing it. I always wanted the nasty stuff to get blown out of the engine. Guess my thinking was wrong because OS is still doing it.

RE: 4 Stroke Crankcase Vent
 

Everybody has their opinon. I agreed with the last post by GrayBeard. OS enginneers recurculate the crank vent oil back into the engine on the newer model engines. My thought was , why not do the same thing, a friend of mine at our club turned me on to this idea, and it works. I have done it, and other pilots also have been doing it. We have also installed Velocity stacks on the carbs, I make my own with tubing and a slight longer than the standard velocity stack. Most smaller 4 strokes don't even have a stack.
The opinion of metal being particles beinging mixed into the fuel again? I don't know about that, all I see is unburnt oil out of the vent. No metal particles at all. Everybody can choose whatever they feel is right for them.
The engines run perfect, sooo. Do what ya want to do.

RE: 4 Stroke Crankcase Vent
 

I have seen people try to use the pressure vent to help add pressure to there fuel tank, yes, it was by mistake but they did it!! As an engine wears weather in or out they do blow a nice gray mater and it is micor metal being worn down by the engine, really can see it well if it is going into your fuel tank!!:eek: Anyway, this is why I questioned the new system on the OS engines?? I have never asked anyone like Bill Baxter about it but it just didn't seem right to me. My new engines all have the new system and I don't have any problems with it. I have opened up engines for rebuild and not seen any signs of a problem so I figure it must be OK?? Even so, I still question having old nasty crap flowing back through my engines?? Sort of like the nasty smog control systems they put on our car engines in the early 70s, talk about gunking things up!!!

RE: 4 Stroke Crankcase Vent
 

Not true, I run my vent line through the body of the plane and have it exit at the tail. It vents fine and all the goo stays off the plane. Also OS runs their vent right back into the carb

RE: 4 Stroke Crankcase Vent
 

I think I read somwhere here an idea of adding a small 1-2 oz tank and letting the vent line run into it. I haven't tried it but it sounds like a winner to me.-BW

RE: 4 Stroke Crankcase Vent
 

Could put a filter on it *shrugs*. Microscopic debris cant be too bad if automobile engines reuse oil for 3,000 miles (or more with synthetics).

RE: 4 Stroke Crankcase Vent
 

They only run it back through the engine because they have to, it's the law. Up until the early 70s all auto engines had a breather on the rocker arm covers venting into the great beyond. If they could get away from the smog systems today you wouldn't see it going back into the engine.

RE: 4 Stroke Crankcase Vent
 

I tend to agree with greybeard, why cycle any impurities and wear particles back through the engine again to create more wear and tear. Any microscopic particles from piston,rod,cylinder etc. will just create and/or accelerate further wear. I know most of the newer designs on 4 strokes do that but; if I were selling engines, I'd like to see the old ones wear out faster too. Now most of that goop coming back out through that breather tube is oil and byproducts from the burning of the fuel, no real value or increase in mileage as the oil does not burn, only the alcohol/methanol is burned unless you are running lean and then; you will have more serious problems as the temperature will be excessive.

RE: 4 Stroke Crankcase Vent
 

I would just drill and tap and put in another nipple to the muffler, and have the breather go out that way. I guess that's the easiest and neat way to do it from my research.


Pete

RE: 4 Stroke Crankcase Vent
 

This brings up another little thing I had discovered when I was building racing engines for sand rails. These were closed system engines and the breather from the rockers went into a K&N air filter. Once we decided to run the breathers through some nice braided stainless steel hose and screw onto some cool looking nipples that went into the stinger/ exhaust pipe. It tended to suck up the oil mist and blow it out so the engine used up a lot of oil fast. Looked really cool though. I know there is no oil in the case on a glow engine but I do wonder if that pressure draw would be doing any harm to the engine??? I have no idea, it's just one of those wonder things?? If it was the thing to do I wonder if OS or saito has ever tried it?? If so why did OS go with the system they use today? Just a thinker! Maybe I have too much time on my hands and shouldn't be doing all this thinking crap??[&o] It hurts my head anyway!!!!;)