PDA

View Full Version : RE: Oil Consumption


fstringham7a
10-06-2009, 06:47 PM
I didn't want to place this on Chris's thread, (didn't want to high jack the tread)

http://www.vansairforce.com/community/showthread.php?t=48754

which I have found very interesting and informative.

But my question is germaine to his topic.

Once an engine....IO360, 0360... is broken in what is the normal oil consumption over a ten hour period of flight time?

Frank @ 1L8 and SGU ...RV7A... Phase 1 @ 30 hours

Geico266
10-06-2009, 06:57 PM
Lycoming has a range of oil consumption. 1/2-2 QTs in 10 hrs is not uncommon.

PCHunt
10-06-2009, 07:59 PM
From Lycoming Service Instruction SI-1427B:

"NOTE
The maximum allowable oil consumption limits for all Textron Lycoming aircraft engines
can be determined by using the following formula:
.006 x BHP x 4 divided by 7.4 = Qt./Hr."

.006 x 160 x 4 divided by 7.4 = .5189 Qt per hour. That is MAX ALLOWABLE.

180 hp engine is .5838 qt/hr.
FWIW

mdredmond
10-06-2009, 08:15 PM
From Lycoming Service Instruction SI-1427B:

"NOTE
The maximum allowable oil consumption limits for all Textron Lycoming aircraft engines
can be determined by using the following formula:
.006 x BHP x 4 divided by 7.4 = Qt./Hr."

.006 x 160 x 4 divided by 7.4 = .5189 Qt per hour. That is MAX ALLOWABLE.

180 hp engine is .5838 qt/hr.
FWIW


I'm no fan of auto engines, but why can't Lycoming make their engines not burn/spew oil? It can't be rocket science if Detroit does it. What am I missing?

ChiefPilot
10-06-2009, 08:23 PM
I'm no fan of auto engines, but why can't Lycoming make their engines not burn/spew oil? It can't be rocket science if Detroit does it. What am I missing?

I would *guess* it is because of the much broader temperature range the Lycs run at vs. auto engines.

N131RV
10-06-2009, 08:25 PM
I'm no fan of auto engines, but why can't Lycoming make their engines not burn/spew oil? It can't be rocket science if Detroit does it. What am I missing?

Lycosauri use ashless dispersant oil to suspend all contaminants within the oil.

In addition, the tolerances on an air-cooled engine are a LOT looser than a watercooled automobile engine, especially when cold. As the engine warms, it comes "together" by design.

A well cared for Lycoming will not "spew" oil. It will consume some through the normal process of combustion, IE, any oil that makes it past the oil rings into the combustion chamber will be burned. That's were the major portion of it goes.

Also, many Lycosaurus do not have oil separators, rebreathers, egr valves, etc. Oil vapor from the crankcase is simply vented overboard. In a tight engine, it's not a large amount. As the engines age, the amounts burned and vented grow as blow-by increases.

It's simply part of the cost of maintenance, I typically use a quart every 4 to 10 hours (yes it varies). A quart every two hours is just a smidgen too much. :)

Finally, if you top your Lyco to the brim, the first quart is often "vented" in short order. I typically run my baby about 1/2 quart from the top for just that reason.

YMMV,

LifeofReiley
10-06-2009, 08:49 PM
engines do not need to leak or consume a lot of oil. I've got 80 hours now on my latest Home Built 320, oil change #1 at 25 hours on mineral, used one quart. Second oil change at 55 hours on mineral, 1/2 quart. I've been on 100W Plus and now have 80 hours, still about 1/2 quart or less. It's all in how you build them. There's a lot of update mods out there for the cases etc... that have resolved most of the issues.

gasman
10-06-2009, 08:52 PM
250 hours on ECI top end. 3/4 of a quart used in the past 26 hours. Phillips multi-grade used for break-in and full time use.