O-290D to O-290-D2

[Steve Pierce]

How come they maintain hp at higher altitude better than the O-320?

[wyandot jim]

Petez, and Others
We have an O-290-2B with about 500 SMOH in our 7GC Champion with a 74-58 prop. As you know to get the 140HP it needs to turn 2800RPM. No way that will happen around 2600-2650 is max in level flight. It is a little low in Max. RPM during static ck.The 74-58 is what it left the factory with and this prop was new at OH. Our O-320 in the Pacer will turn 2700 with the same prop no problem.
I'm curious to know what RPMs you get with what prop.
For that mater I would like to hear what some of the others with O-290s are getting with what prop

[51-pa22]

.....I have converted the 0290 by having the case reworked to accept the hydraulic. ...

Other than replacing the cam and lifters, what case modifications?

[nimdave]

Here is a quote from the 0-290 operations manual;
Hydraulic tappets which automatically keep the valve clearance at zero are employed on the
O-290-D2 series engines while solid tappets are employed on the O-235 and O-290-D series.
Proper valve clearance on the latter models is maintained by means of an adjusting screw
located in the valve rocker.

[51-pa22]

Thank you nimdave
But I am looking for a little more detailed info here. As in is the diameter of the cross drilled oil holes in the tapped bores different. You know? The oil used to pump up the hydraulic lifters one only used as a lug for solid lifter bodies and the little splash lube for the rocker arms for both the -D and the -D2
Or the location in the front breather port drilled different, is the front cam bearing surface longer on a ?

Or what is the technical difference between LW-10070 and LW-10071

[Steve Pierce]

Thank you nimdave
But I am looking for a little more detailed info here. As in is the diameter of the cross drilled oil holes in the tapped bores different. You know? The oil used to pump up the hydraulic lifters one only used as a lug for solid lifter bodies and the little splash lube for the rocker arms for both the -D and the -D2
Or the location in the front breather port drilled different, is the front cam bearing surface longer on a ?

Or what is the technical difference between LW-10070 and LW-10071

Call Divco, that is what they do.

Sent from my SM-N900V using ShortWingPipers.Org mobile app

[51-pa22]

Steve, I like that answer....

[nimdave]

Sorry 51-pa22 but my post was not meant for you but a correction to another post.

[51-pa22]

No prob, always like info.
Never know when you may learn something and

most of the time I’d really doesn’t hurt.





Much

[petez]

If you look at lycoming performance charts, fuel burn charts, and lycoming specs you will see all this information. I have a set of lycoming manuals that go back to the late 50s. This where I got my information. Bore , stroke, compression, etc all play a part in engine efficiency. Why do cars, planes , trucks, engines, that are same make model year etc, get better mileage, make more power, last longer, run smoother, than others ? All I am saying is a lot of folks bad mouth the 0290 engines, have never owned 1, flown behind 1? Any time you buy parts from lycoming you pay top dollar. When we have the option to buy certified parts from other manufacturers we get a better cut on price. There are a few of the 0290 parts that are only made buy lycoming or are such demand that prices are high. As far as props lycoming tests their engines with what they think is appropriate.