0-320 overheating on first take off

[hoyden]

Originally Posted by lr172

That is WAY more fuel than necessary for a 320. There are many other options to keep an engine cool other than throwing excessive fuel at it.

A couple weeks ago I was up to Aero Sport Power to build my IO-320. I witnessed the engine test where they ran my engine for a total of 1 hour 20 minutes in 3 test runs at 2620 rpm and 27". Fuel flow was 16.4 to 16.6 gph. CHT was 310-330F. My RV-6 IO-360 flows 17.5-18.2 gph WOT. Ballpark fuel flow of HP / 10. I'm happy burning some extra fuel to keep CHTs below 400.

[lr172]

Originally Posted by hoyden

A couple weeks ago I was up to Aero Sport Power to build my IO-320. I witnessed the engine test where they ran my engine for a total of 1 hour 20 minutes in 3 test runs at 2620 rpm and 27". Fuel flow was 16.4 to 16.6 gph. CHT was 310-330F. My RV-6 IO-360 flows 17.5-18.2 gph WOT. Ballpark fuel flow of HP / 10. I'm happy burning some extra fuel to keep CHTs below 400.

That seems like a lot. My 540 only takes 24-25 GPH 29/2700 and relatively that would be 16 or so for a 360 and 14.5 for a 320. I guess I wasn't thiking of a CS prop that turns 2700. I don't get much over 2500 down low with my FP and why I see mid 13's.

[RV8JD]

Originally Posted by hoyden

A couple weeks ago I was up to Aero Sport Power to build my IO-320. I witnessed the engine test where they ran my engine for a total of 1 hour 20 minutes in 3 test runs at 2620 rpm and 27". Fuel flow was 16.4 to 16.6 gph. CHT was 310-330F. My RV-6 IO-360 flows 17.5-18.2 gph WOT. Ballpark fuel flow of HP / 10. I'm happy burning some extra fuel to keep CHTs below 400.

Originally Posted by lr172

That seems like a lot. My 540 only takes 24-25 GPH 29/2700 and relatively that would be 16 or so for a 360 and 14.5 for a 320. I guess I wasn't thiking of a CS prop that turns 2700. I don't get much over 2500 down low with my FP and why I see mid 13's.

Here is my 180 HP Lyc IO-360-M1B with the AvStar FI, Hartzell BA CS prop, DA=248', full rich, just after TO. Flows 17.1 GPH +/-. Seems about right per the Lyc charts.

The 160 HP Lyc IO-320 operator's manual states rated power, full rich limits as 13.8 to 15.2 GPH.

[MacCool]

Originally Posted by hoyden

When I finish my RV-9 with an IO-320 I will be expecting to see fuel flows no less than 15 GPH.

Yikes! I’ve never seen fuel flow that high on my IO320D1A in any circumstance, nor can I recall seeing CHTs higher than 400 degrees.

[lr172]

Originally Posted by MacCool

Yikes! I’ve never seen fuel flow that high on my IO320D1A in any circumstance, nor can I recall seeing CHTs higher than 400 degrees.

Me either. That is why I was so surprised when he posted it. Chart in Lyc operators manual for 320 (160 HP) says 14.5 GPH at 29/2700 at SL; Pretty much what I estimated in my post above. They tend to be pretty conservative so not sure why you would throw more fuel at it. THey also say 10 GPH at 75% power and from my experience ROP at 75% power is a closer to 9. I tend to be only 150 ROP on the rich side and never see 400 CHTs down low. Above 8K is a different story, as the ignition keeps advancing and raises CHTs.

Larry