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larrynimmo

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Wasn't clear on one point...I consider it a hot start up to an hour or so after shutdown...but I have to amend my post, if I shut down for a few minutes, like dropping off a passenger, it'll start right back up using the hot start method...if I have lunch and do the hot start procedure that's when it dies after starting up just fine. So, Jetdriven's comment makes perfect sense about what happens to the fuel  shortly after engine shut down.

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On 9/30/2019 at 1:50 PM, Sandman993 said:

So lemme get this straight...and by the way, what you say makes sense. Often with this new engine, my hot starts want to die after start up...doesn't matter how good it works, it usually runs for a couple seconds then runs out of gas...by the time I get back on the key, it starts right up. The old engine never did that, a hot start was easy and it didn't seem to ever falter. So, where does the fuel pinch point occur? I'm always afraid of the boost pump because I don't want to flood the engine when hot. I don't have to tell you how embarrassing that can get.

You can crank it with the electric fuel pump on.  When it fires, give it the mixture lever. The electric pump will keep fuel pressure steady.  After 10-15 seconds the hot air blows from the cowling, you can turn off the electric pump. 

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On 9/8/2019 at 6:09 PM, PT20J said:

Begin with throttle set for 1000 rpm, mixture ICO and crank. If it doesn’t fire in a couple of revolutions, slowly richen mixture until it fires, the go to full rich and adjust rpm with throttle. 

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Agree that this often works. But, I’m quick to go at least half throttle or more with mixture idle cut off to begin with. This is my go to 100% success for hot and warm Lycoming engine starts whether or not you hit the boost pump for a couple of seconds. I like the KISS (keep it simple stupid) warm/hot Lycoming start. Throttle in significantly, mixture ICO, crank starter, mixture in, throttle back as engine starts and adjust mixture and throttle smoothly. This is the only method that has consistently worked for me on every warm/hot Lycoming start. 

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2 hours ago, HXG said:

Agree that this often works. But, I’m quick to go at least half throttle or more with mixture idle cut off to begin with. This is my go to 100% success for hot and warm Lycoming engine starts whether or not you hit the boost pump for a couple of seconds. I like the KISS (keep it simple stupid) warm/hot Lycoming start. Throttle in significantly, mixture ICO, crank starter, mixture in, throttle back as engine starts and adjust mixture and throttle smoothly. This is the only method that has consistently worked for me on every warm/hot Lycoming start. 

Just not a big fan of waking up an engine at high rpm. A lot of bare metal rubbing going on until the oil gets flowing. 
 

installed fine wires I’ve been looking at for a month today... hopefully that will help, but I’ll definitely play with what jetdriven suggested.

btw, we did the leak down check for annual today... at 160hrs smoh... Horse power plus stc’d 10:1 pistons were 3) 79’s/80 and one 78. Gami’s go in tomorrow.

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10 hours ago, carusoam said:

Gamis, fine wires, and 10:1 compression...

Sandman, what ignition timing are you using?  20 or 25° BTDC?

Got any JPI data to share with that?

That will make an interesting set of data.

Best regards,

-a-

A quick preliminary report on what I have so far...

Been thinking this ship was at max potential up to this point, or close to it. New plugs at overhaul along with new wires and fresh mags (dual). I'm about 155 smoh and wanted gami's because the #3 on this A3B6D engine runs 30 degrees hotter. Gami say's that's typical. Simply wanted it to be more inline with the others.

So, yesterday afternoon and everything back together, did the traditional leak check and mag check. Feeling emboldened, I took her to the runway for a takeoff run (at our little country airport) with a plan to abort of course. With the new setup, I saw a 50 rpm over redline.  I'll have to re adjust the prop gov, but think I'm gonna like this.

Hopefully, I'll get her in the air today so I can look at the temps across the board as I'm sure there will be some changes. More power, more heat to manage. Only wish the components were changed one at a time so I'd know where the wholesale change came from.

Ps...I lost a mag back at 75hrs because of lock tight on the cap threads...there's an SB on that. It states using thread locking substance can cause loss of grounding to the distributor cap...that can cause the condensers to fail (one or both) which causes the points to get hot and melt the plastic follower. So, I had one side fail and now have another mag overhaul at the princely sum of 1300 bones. Yay! It came back from overhaul at 28 btdc...I have it at 25 now because that's legal and easier to start.

My plan is to cowl her up and fly today, if I can escape my normal duties. Will report in when I see what's changed aloft.

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On 10/9/2019 at 12:05 AM, carusoam said:

Gamis, fine wires, and 10:1 compression...

Sandman, what ignition timing are you using?  20 or 25° BTDC?

Got any JPI data to share with that?

That will make an interesting set of data.

Best regards,

-a

Ok, after two short flights yesterday, I didn’t see any major differences in performance except as I mentioned before, it starts easier with the fine wires. It’s running good... the gami’s made a nice difference in that the hottest #3 is now a few degrees below the new hottest #2 and the coolest cylinders 1&4 are all much closer. What really has me confused is, while the chts are closer now and hottest down to better match the others, the egts are dramatically lower... in the mid to high 12’s. I’m normally in the mid 13’s.
 

I tried jetdriven’s hot start process after a thirty minute shutdown... happy to report, it’s works better than the usual run for three seconds and die. Thanks jetdriven for your insight.

my son in law has a nice j that just had a top overhaul... after he gets to break in, I’m hopeful that he will humor me and allow us to have a matched flight to see how the high compression pistons and the power flow muffler perform next to a stock, fresh, good running j. 
 

 

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