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Message |
    
Tomk
Visitor
| | Posted on Tuesday, May 20, 2008 - 03:34 pm: | 
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I have a P60 it runs good but the oil pressure stays somewhat low,15 to 25 and its full throtle is no more than 1600 rpm in gear.Is this normal. |
Richard Shapiro
Senior Member
Username: mainesails
Post Number: 62
Registered: 09-2005
| | Posted on Tuesday, May 20, 2008 - 03:47 pm: |
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In a word, yes, assuming you have a typical direct drive P60 installation (no v-drive and Right Hand rotation propeller). Your oil pressure is also typical. |
Richard Shapiro
Senior Member
Username: mainesails
Post Number: 63
Registered: 09-2005
| | Posted on Tuesday, May 20, 2008 - 03:48 pm: |
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I'll explain why in detail when I get some time (unless someone beats me to it). |
Eddie Ross
Senior Member
Username: eddie
Post Number: 212
Registered: 04-2003
| | Posted on Tuesday, May 20, 2008 - 04:52 pm: |
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Not low enough to be of concern. There might be some loss due to normal wear of the bearings but nothing that you could not live with for years to come. You could virtually continue indefinetly the current state of your engine by being meticulous about changing the oil and oil filter element. I trust that you are running straight 30 weight oil. |
Tomk
Visitor
| | Posted on Tuesday, May 20, 2008 - 04:54 pm: |
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Re:Low RPM The P60 in in a Coronado 30,would a different prop improve performance? |
Eddie Ross
Senior Member
Username: eddie
Post Number: 213
Registered: 04-2003
| | Posted on Tuesday, May 20, 2008 - 06:35 pm: |
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The RPMs are basically ballpark for that kind of engine. Remember the basic engine is for a 1940s era tractor. A simple, durable, lugging type engine. |
Richard Shapiro
Senior Member
Username: mainesails
Post Number: 64
Registered: 09-2005
| | Posted on Tuesday, May 20, 2008 - 08:03 pm: |
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The redline is 3000 rpm, BUT unlike a diesel, a P60 can run indefinitely lugging at low revs.
These engines were generally installed direct drive - so that the prop turns 1 turn in forward for every turn of the engine. If the prop were sized to allow the engine to rev to the redline, it would be the size of CD-ROM - and would be hideously inefficient.
The decision was made to install these fairly large engines and consciously use them to 1/2 their rated horsepower - in other words at around 1500 rpm. I assume this decision was made because of the simplicity, reliability and low cost of the engine.
By the way, many prop-shops, if asked to diagnose a P60 (and possibly even an A4) will not know of the above situation and will recommend a rediculously small prop.
You might also note that the engine revs much higher in reverse than in forward. This is due to the fact that the engine IS geared 1.3:1 in reverse! Generally, this means that, with the stock prop, thrust in reverse is minimal at best.
New technology props from Indigo and CDI intended for the Atomic 4 also work on the P60, which has the same torque curve to its redline of 3000 (the A4 continues to 3600, giving it a higher HP rating - but the engines produce the same power as generally installed). |
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