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  #1  
Old 08-15-2019, 11:18 AM
witek witek is offline
 
Join Date: Jan 2013
Location: Poland
Posts: 88
Default RV7A IO360, detonation ?

Hi All,
Have you had similar case?
This happened while tryied to start a hot engine on the ground (after the first flight).
Photos here:
https://drive.google.com/open?id=153...pz6kV918bpwcdK

Many thanks for ideas and solutions.

Witold
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  #2  
Old 08-15-2019, 11:26 AM
BobTurner BobTurner is offline
 
Join Date: Dec 2011
Location: Livermore, CA
Posts: 5,863
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These photos look more like during the hot start you flooded the intake and had a fire there. Detonation occurs within the cylinder, under certain (hot, high MP, high compression, low octane) conditions.
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  #3  
Old 08-15-2019, 12:14 PM
wnplt wnplt is offline
 
Join Date: Feb 2013
Location: Idaho
Posts: 124
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I had that happen once on a hot start. I no longer hot start with the throttle wide open. It was a backfire that blew mine. I hot start by throttle open 1/2 inch, mixture out and as I crank slowly push in mixture. That seems to work fine and havenít damaged the air filter since.
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  #4  
Old 08-15-2019, 01:35 PM
airguy's Avatar
airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 4,704
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Yes, that was a backfire/airbox fuel ignition event, not a detonation event.
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  #5  
Old 08-16-2019, 01:36 AM
witek witek is offline
 
Join Date: Jan 2013
Location: Poland
Posts: 88
Default RV7A IO360, detonation ?

Many thanks for all replayes.
Have to find a better method for hot start.
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  #6  
Old 08-16-2019, 06:47 AM
Southern Pete Southern Pete is offline
 
Join Date: Jul 2015
Location: England
Posts: 33
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Lots of advice on the internet - some fuel, but not too much is required. The skill is knowing how to achieve that.

You will develop your own technique that works on your airplane.
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  #7  
Old 08-16-2019, 06:49 AM
Monkey Monkey is offline
 
Join Date: Jun 2006
Location: Roanoke, Texas
Posts: 69
Default Backfire

Just a tad too lean. Run the boost pump 1-2 more seconds.
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  #8  
Old 08-16-2019, 08:31 AM
Boyd Birchler Boyd Birchler is offline
 
Join Date: Sep 2014
Location: IN
Posts: 202
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First re-start? I would look at the timing and hook ups to the mags. It looks like it fired advanced.

That could be because the mag switch is grounding the mag with the impulse coupler instead of the non-impulse mag.

The impulse mag may have been timed without releasing the impulse coupling.

If your engine is a "shower of sparks"you could be starting on the advanced points instead of the retard breaker.
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  #9  
Old 08-16-2019, 09:06 PM
pr1malr8ge pr1malr8ge is offline
 
Join Date: Oct 2014
Location: NW Indiana
Posts: 14
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Seems some people are trying to correct the OP....

Detonation means a multitude of things in the English language.. Since the OP is from Poland my guess English is not his primary language there for it's easy to reason he meant back-fire..

Last edited by pr1malr8ge : 08-16-2019 at 09:14 PM.
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  #10  
Old 08-17-2019, 06:15 AM
2Big2Ride 2Big2Ride is offline
 
Join Date: Sep 2015
Location: Fort Worth, TX
Posts: 18
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Quote:
Originally Posted by pr1malr8ge View Post
Seems some people are trying to correct the OP....

Detonation means a multitude of things in the English language.. Since the OP is from Poland my guess English is not his primary language there for it's easy to reason he meant back-fire..
Reminds me of a situation long ago with a Japanese motorcycle manufacture. Dealers claimed a particular newly released motorcycle had a slight running problem and was back-firing. The OE spent many hours researching and could not replicate the problem. Turned out it was a difference in terminology commonly used in our two different base languages. We should have reported the problem as an after-fire, not a back-fire. One was considered a problem through the exhaust, the other was through the intake.
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