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  #11  
Old 11-24-2017, 01:40 PM
fbrewer fbrewer is offline
 
Join Date: Sep 2017
Location: Leander
Posts: 20
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Well dang, I was less than clear in my original post.

We have an IO360 - it is fuel injected -- so NO carburetor. So back to the original question

Our starting checklist has the following step:

Prime with Throttle - Prime!

I think I know what is happening, but would like your comments.

What does this mean?

How do I Prime?

What happens when I Prime?
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  #12  
Old 11-24-2017, 02:01 PM
mbauer mbauer is offline
 
Join Date: Nov 2015
Location: Nikiski, AK
Posts: 107
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Quote:
Originally Posted by Ironflight View Post
Here's a little video I shot of the accelerator pump in action:

https://youtu.be/VtMB-3U6sc8


For a description, you can see my blog post from a few months back on Kitplanes.com:


https://newsline.kitplanes.com/2017/...mp/#more-10964
Just checked out the blog. I do not have a prime system. Temps have been below +30 deg F for some time now.

My RV 0320 has been starting ok, usually 2-3 turns, however I've been pre-heating using 4-each hair dryers. Two in the intakes and two in the bottom of the cowl through the exhaust openings. Cylinder head temp show above 100 deg by the time the preheat is done. Removing ice/frost takes 1-hour: whole time preheat is on-going.

Have not been using the "prime" method of pumping throttle. Just cracking open the throttle about 1/4".

Will try the "prime" method later today.

Thank you for the blog!

Understand the OP has modified his question explaining "IO 360". But wanted to say thanks, learned something from the answers provided for the "carb prime method".

Best regards,
Mike Bauer
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  #13  
Old 11-24-2017, 04:18 PM
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humptybump humptybump is online now
 
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Location: Eastern Shore of Virginia
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Caveats: #1, it does not apply to the OP because he clarified he is asking about FI; caveat #2, for the life of me I can not find the original material.

OK, short of the above, sometime in the past two weeks I’ve read an article, seen an authoritative video, or attended a webinar where the topic was:

Using the throttle’s accelerator pump during engine start

The critical point of the presented material was “hit the starter and THEN quickly jab the throttle to activate the accelerator pump AND QUICKLY pull the throttle back.”

The presented material went on to say, “pumping the throttle without the starter activated means the fuel will quickly pour back out of the carburetor into the airbox. If the engine should backfire, the airbox is a volatile chamber and fire is a real potential.”

UPDATE: the source I was looking for was the EAA webinar “Fly the Easy Way”
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Last edited by humptybump : 11-24-2017 at 04:24 PM.
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  #14  
Old 11-24-2017, 04:53 PM
Michael Burbidge Michael Burbidge is offline
 
Join Date: May 2006
Location: Sammamish, WA
Posts: 552
Default Transition training

I did transition training with Mike Seager in N666RV. (O-320) The standard procedure he taught for N666RV was 5 pumps on the throttle, then hit the starter key.

I've used that same procedure for my airplane, except that I only use 3 pumps on the throttle.

I'm always puzzled as to the diversity of opinions about these kinds of things. But Paul's video certainly convinces me that I should change my procedure.

Michael-
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Last edited by Michael Burbidge : 11-24-2017 at 05:22 PM.
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  #15  
Old 11-24-2017, 06:22 PM
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sirlegin sirlegin is offline
 
Join Date: Feb 2006
Location: Keller, Texas
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My 0320 fuel injected takes 6 seconds, WOT and full rich, of boost pump then turn it off and crank. Starts on first swing of prop every time.
I learnt about the amount of time with boost pump for prime when I overdid it and had fuel pouring out and lost my K&N filter red oil.
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  #16  
Old 11-24-2017, 06:35 PM
rv7charlie rv7charlie is offline
 
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Location: Pocahontas MS
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Just to add a little more clarity...

Somebody mentioned priming 'into the head'. I've seen posts in the past (other threads) where people thought that the primer (or injection nozzles) injected into the combustion chamber. That is not the case. Both the carb'd engines with primer lines, and injected engines using fuel pump for priming, are squirting fuel into the intake path, short of the intake valve. Since Lycs have their intake tubes on the bottom, the fuel will still run downhill, toward the intake. So....any of the three techniques can end up with fuel pooled in the bottom of the intake system, if priming is done incorrectly.

As an aside, I don't often feel old, but when the majority of males in a conversation about internal combustion engines don't know how a carb (with accelerator pump) works, I start to wonder if I'm past my sell date. :-)

Charlie
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  #17  
Old 11-24-2017, 06:37 PM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by rv7charlie View Post
... I start to wonder if I'm past my sell date. :-)

Charlie
Or worse, "use date"!
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  #18  
Old 11-24-2017, 07:01 PM
OkieDave OkieDave is offline
 
Join Date: Mar 2017
Location: Oklahoma
Posts: 52
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I suppose the real question is why we haven't moved to direct injection like the rest of the technological world. It seems to solve a lot of problems, and improve efficiency (and emissions) significantly.

If my tractor can manage it--at less total cost than an aircraft engine alone--why can't we get with the times?

(Serious question, BTW--what am I missing here?)
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  #19  
Old 11-24-2017, 07:16 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Location: Hubbard Oregon
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Quote:
Originally Posted by OkieDave View Post
I suppose the real question is why we haven't moved to direct injection like the rest of the technological world. It seems to solve a lot of problems, and improve efficiency (and emissions) significantly.

If my tractor can manage it--at less total cost than an aircraft engine alone--why can't we get with the times?

(Serious question, BTW--what am I missing here?)
To a large degree it is design/development costs

When the cost of a new design is going to be spread among a sales volume in the 10's of thousands (in the case of cars, 100s of thousands), it doesn't have nearly the impact on selling price that it would if the sales #'s are only a fraction of that (as they would be with an aircraft engine).
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  #20  
Old 11-24-2017, 07:23 PM
rv7charlie rv7charlie is offline
 
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Depends on what you mean by 'we'. :-)

Regular electronic injection isn't too big a hill for a 'cottage industry' vendor to climb, but direct injection is a whole other mountain. A lot more complicated than just figuring out how much fuel to squirt. A primitive diesel just does a metered squirt, but newer computer controlled diesels (I'm told) vary timing of the injection, both start timing and rate. Same for gasoline direct injection. Software is complex, and hardware even more so, with injection pressures measured in thousands of psi. Pretty tough to manage in a low volume industry.

Now if you're willing to use an actual alternative engine, instead of just alternative fuel delivery....
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