thrashin

Checked that... inlet manifold is rock solid in the head, no movement. Any other ides? Does the highspeed needle effecting idle indicate anything you know of?

This is a fairly new .72 and has the reinforced backplate. Does it sounds like an air leak?

w8ye

My Feedback: (16)

It is less than 18% by volume of the total fuel volume consumed.

The Saito's with two bosses in the back plate can utilize the Saito in-out check valve system.

you may be able to use a small fuel tank as a catch trap to accumulate the expelled oil when using the check valves

w8ye

My Feedback: (16)

I never had a Saito where the idle mixture was materially affected by the high speed needle.

My initial impulse would have been to open up the low speed to be even with the outside of the throttle arm. Throttle the engine up to full throttle and adjust the HS needle for peak, then go back and adjust the LS needle for best compromise between smooth idle and transition to high speed.

In the end, the HS is re-adjusted 500-600 rpm rich

RPMcK

My Feedback: (1)

Mike, the blow by oil is what I'd like to find a way to deal with. Just wondered how much is emittred and if it could be contained in small enough contairner to make it practical to catch it or just let it eject overboard. I haven't even ran my 180 yet so I have no idea what to expect. That's why I'm asking questions.

RPMcK

My Feedback: (1)

w8ye - sorry about the -w8y3 thing - typo

w8ye

My Feedback: (16)

No Problem

mike early

I will be using a long fuel line routing the crankcase vent out of the bottom of the cowl. Not very pretty. My engine is still new, but I was amazed at the amount of oil coming out of there when running on the bench. I am sure it will decrease with time. My fuel has 20% synthetic oil. I presume that lower oil content would result in less mess. Less lubrication too, of course.

I wonder if castor oil creates a better seal with the piston, resulting in less blowby?

RPMcK

My Feedback: (1)

Mike, Appreciate your input. Thanks. Ron

RPMcK

My Feedback: (1)

w8ye, I hadn't thought about the small fuel tank thing. Good idea, thanks.

Hobbsy

My Feedback: (102)

Mike, I have on several occasions ran Saitos for 10 minutes then immediately pulled the backplates to see how much oil is in them. I have done this with 16%, 18% and 20% lube oil and there is always the same amount in the crankcase, so one has to conclude that the higher %s flow through the engine faster than the lower %s. RCV recommends against more than 16% lube and if you watch my .58CD you can see why, it really spews oil when 18% is used although it has never hurt the engine. In the case of the RCV the caution is due to the small combustion chamber but the flow difference is visible.

Capt Lou

Guys:

Regarding the vent tubing, I have read (altough I can't remember where I saw it) that the vent tubing should be no longer than 4-41/2 inches and you should use a large diameter tube. My recollection is that you need to be concerned about the tube bend creating back pressure and that this would also occur with too long of a tube. I wish I could tell you more about this but I don't recall the source. Maybe someone can jump in on this matter.

linkadrip

So this means that the tube i have on my crankcase vent is to long and is going to create to much back pressure on my crank case. I seen no other option then to run the tube from the engine and route it to the bottom of the cowl and the tube is probably over 4 1/2 inches.

So buy looking at these pictures of the plane i have my saito in does this mean i'm going to have to route the vent tube out the top of the cowl. would hate to have all the blow buy going all over the cockpit and the top of the plane.

the tube has no kinks in it and the engine Seems to run fine with the tube routed over the top of the engine and looped around to come out the bottom.

blw

My Feedback: (3)

Your vent tube installation looks fine and I wouldn't change it. I think the 4 1/2 inch length was an observation by someone and not a factual limitation. A large diameter wouldn't hurt anything if you can keep it attached to the vent nipple.

RC Specialties

Link,

I run my case vent out the bottom of my cowls on all my planes. They are all more than 4 1/2 inches. I have not had any problems with excess back pressure. On my test bench the vent line is run to a tank and is about 18 inches long. The oil has no problem getting to the tank. I can see a problem if it kinks. Has anyone else had a problem with a long tube?

Jim

w8ye

My Feedback: (16)

The vent tube should be looped and run out the bottom of the cowl

linkadrip

Thanks everyone i worried there for a minute.

RPMcK

My Feedback: (1)

Jim,

What's the story on the muffler on your beautiful blue bi-plane? Doesn't look like one of your's!

Ron

SigMan

My Feedback: (21)

i was thinking of running a line from the breather nipple up to muffler to help burn some of the oil off, instead of having a oily mess on the bottom side of my plane. has anyone ever tried this?

mike early

The 4 1/2" max number probably came from the max suggested length of line from the crankcase to a Perry Pump.


If you have 2 pressure fittings on your exhaust, or are not pressuring your fuel tank with exhaust, I don't see how the crankcase blowby oil would hurt anything by going to the exhaust. Actually I like the idea. What say the moderators?

w8ye

My Feedback: (16)

I often pipe the crankcase vent to a point along side the exhaust outlet so they both come out the same place

mike early

Another great idea from the Saito Club! Thanks!

mike early

Ah, after re-reading your post, w8ye, I see that I misunderstood. You are not tapping your exhaust. I think I will add another pressure fitting to my flex pipe and route the blowby out the exhaust, in the manner SigMan has suggested. Any possible problem with that?

w8ye

My Feedback: (16)

However there is some resistive back pressure inside the muffler.

Anything is worth a try.

In my escapades, I never piped the crankcase into the exhaust. I just put the crankcase vent beside the exhaust outlet. I used a short piece of K-S brass tubing fastened to the muffler with a small hose clamp. I used a piece of fuel tubing between the crankcase vent and the piece of tubing fastened beside the muffler.

Michaelh

My Feedback: (4)

Going on the idea that the breather is sucking and blowing I guess it would be sucking in exhaust gasses into the crankcase now.

N1EDM

My Feedback: (2)

Hi Thrashin,

Your problem still sounds like an air leak issue to me. When checking that backplate, did you notice if all the screws on the backplate were tight? I presume that you did. The first thing that I would recommend is to put in a fresh plug of the type that you were using before and had success with - you said you had tried a variety of plugs, so I want to suggest putting in a new one. Then, read the manual and reset the needle valve and the LSN to the factory specs, then try it again.

Is anything different from when the engine had been running before? Is it in a new plane with a different fuel tank location? Where it remains side mounted, I'm guessing that the answer is 'no', that it is still in the same plane.

How about the fuel lines? Could they have a small puncture in them, whether it be the fuel line or the pressure line from the muffler? I'd be curious to find out what the solution is.

Bob