0-290-D2 oil out Case Beather

[Homer Landreth]

I know that this has been done on an individual basis, but any recommendations like this (IMHO) should be delivered with much discretion. I actually have experience that this attempted remedy is not always effective, and is not "the answer", and should not be presented as such. There are threads on this site for this subject that show there are other factors in oil blowover.

Lou

I knew that. I just thought that would be a "kind and gentle" way to smoke someone out of the bushes to say that fix is really not for all but a small hand full of people here to even know about let alone try to do it.

[Pacerfgoe]

I knew that. I just thought that would be a "kind and gentle" way to smoke someone out of the bushes to say that fix is really not for all but a small hand full of people here to even know about let alone try to do it.

I'm not saying he should attempt this himself, but I'm just putting it out there that this is a fairly well known problem, and it's something to look for.....His engine with only 200 since OH should be broken in, and not be blowing oil out the breather.

Maybe Homer isn't comfortable doing this, but I would be.....after covering all the other bases.

[750-Miller]

Jim, All;

Thanks for the shot / mark-up of the Whistle slot. Took a deeper look into the cowl and found that there is one there now. Its just above an attach point , on the fire wall, about 6" up from the belly and faces forward , ( in this neutral pressure area should not make any difference which way it faces .... as long as it is there and open). If you weren't looking for it world never see it without the cowl off.

So, no need to make that mod. But since the vent Pipe ends down about 3" below the cowl, ( and is cut at a 90 ), will turn that into a 45.

Once I rotate the Rt. angle Case Vent fitting up,( 180 degrees from where it is currently pointing ), and attach the Airflow Systems oil separator, ( close to the case fitting to get the 15 degree down angle to the case that Airflow calls for) , and reroute the vent line across and over the top of the motor to connect to the hard line vent pipe at it's present location; ( and log some Hrs ), will get back with the results....

Will be holding off on more aggressive measures for now.

John

[wyandot jim]

John,
Let me say this one more time about our breather on or Champion 7GC with a O-290-D2.
After looking at it this weekend. It is stock. It goes down hill from the front of the case. It is cut off square and sticks down into the slip stream by about 2-3 inches. The belly has not been cleaned for 15-20 hours ( That is Grandson job) and does not need it now. The engine might use a QT. ever 15+ hours and has 450 hrs on it with chrome cylinders.
So IMHO if yours is using 1QT every 3 hrs. You have a problem other than a breather. The pressure is coming into the case by the rings. Maybe glazed cylinders or something.
All I know is our engine doesn't do all of the crap an O-290 is supposed to do.

[Homer Landreth]

I'm not saying he should attempt this himself, but I'm just putting it out there that this is a fairly well known problem, and it's something to look for.....His engine with only 200 since OH should be broken in, and not be blowing oil out the breather.

Maybe Homer isn't comfortable doing this, but I would be.....after covering all the other bases.

Homer would not be "not comfortable " with doing it, he would not touch it with a 10 foot pole. What do you use for "Approved Data" for the amount you cut off ?

[Pacerfgoe]

Homer would not be "not comfortable " with doing it, he would not touch it with a 10 foot pole. What do you use for "Approved Data" for the amount you cut off ?

It's on a Zenith Homebuilt....no approval required

[Homer Landreth]

It's on a Zenith Homebuilt....no approval required

. The fact that this discussion morphed to only be about experimental planes wasn't clear. Registered plane types were mentioned. At any rate I think that just chopping off part of an engine part to stop oil consumption should have a little more investigation behind it to preclude unintended consequences.

[gliderman]

I just went through this camshaft conundrum last year.....

as you know 0-290 parts are becoming hard to find. you can't get new pistons, piston pins, cylinders anymore; Just to name a few things.....

the camshaft for a 0-290 d2 ( integral gear) is part no 76094- it is no longer available- and the price at Aviall is $4800 USD if you could get one- holy moley

the 0-320 camshaft- 76097 is practically the same-they both have the same grind, lift etc. the only difference is that the 76097 cam is just a little longer.

so as you probably surmised 0-320 cams are making their way into 0-290's. but if the cam is not machined down it will stick into the cavity below the breather happily flinging oil out the breather

I'm not condoning in any way shape or form that folks happily interchange these two cams on certified A/C, But on a Homebuilt- absolutely no problem as I see it

a lot of 0-290 crankcases are being machined out to accept 0-320 cylinders- strictly experimental/ homebuilt- i'm gonna check to see if it is allowed under the Owner Maintenance category we have up here in the Great White North

Shane-o

P.S. I found a two piece cam that was the right part no- so I'm still legal

[Steve Pierce]

. The fact that this discussion morphed to only be about experimental planes wasn't clear. Registered plane types were mentioned. At any rate I think that just chopping off part of an engine part to stop oil consumption should have a little more investigation behind it to preclude unintended consequences.

Call Lycoming or many engine rebuilders. They will tell you the same thing. It is not chopped off. An 1/8" or maybe a tad more is turned down in a lathe after the cam is laid in the case to see if you have one of the offending cams. And the one I saw was the O-290 cam not an O-320.