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-   -   Super 8. Documenting an engine overhaul with JB Aircraft (https://vansairforce.net/community/showthread.php?t=106087)

Kahuna 01-02-2014 08:02 AM

Quote:

Originally Posted by turbo (Post 839128)
kahuna, that is one nice xmas present. happy new year and many safe flying hours. great education on engines. do you have a final tally on the entire project? has it gone upside down yet? :)

Thanks to our team partners, JB Aircraft:), ECI:), & TS FLightlines:), my out of pocket is mostly in accessories.
I spent ~$700 to overhaul AFP servo, spider and new injection lines.
~$400 on new ignition wires and plugs from Lightspeed.
A few hundred dollars in odds and ends like adel clamps and things.

donaziza 01-03-2014 08:13 PM

Hi Kahuna, Did I miss it? Was looking for what your mechanic thought about all the LOP hours

Kahuna 01-04-2014 04:51 AM

Quote:

Originally Posted by donaziza (Post 840407)
Hi Kahuna, Did I miss it? Was looking for what your mechanic thought about all the LOP hours

Ill get him on this. He has been recovering from a holiday of fishing with his boys. Thanks for reminding me.

Kahuna 01-24-2014 07:55 AM

Running strong
 
Update:
The engine is doing very well with about 6 hours now. Im fiddling with flow matching injectors, and even cht distribution. I also have one pesky mag cover bolt oil leak. One of the items that took some fiddling was the timing.
I run dual LSE ignitions with a direct crank pickup. As a result of increased compression, the timing needs to be adjusted a bit. The bad news it that in order to do this, its a complete prop pull. Which on a fixed pitched prop, no problem. But these c/s props, well, its a finger chore. Since the original 8.7:1 compression was a 25deg timing, and the new timing needs to be 20, this required either a set of computer swaps, or a board adjustment. I choose the later.
In the picture below, taken from above the engine, looking down and fwd on the case at the nose, crank flange is at the top of the picture, you can see item mark A is the case split. Normally you line up the case split with the arrow on the board marked B. These 2 were lined up in the original set up. To retard the timing from 25 to 20 (make it fire later in the stroke, Later equals retarded and earlier equals advanced. Why they make this verbiage so confusing is beyond me), simple move the board in its mount slots. Thats the good news. The bad news is that its not that easy to know exactly how much movement there needs to be to capture the timing you want. Its a swag. And the only way to know exactly what timing you have is with a timing light. Thats a prop off, board move, prop on, test, prop off, board move until done activity.
In this picture I went from 25 to 18. Rats. Went to far. I settled in on half the distance.


NOTE: measuring the timing with a timing light is rather difficult on a tail dragger. Your up on a step stool behind the prop with the engine running pointing your timing light fwd to the aft side of the ring gear, looking for the case split and the ring gear marks you marked with white paint, doing the best you can trying to eyeball a line up. Praying that you don't slip and fall and kill yourself. I ended up making a pointing device out of scrap aluminum that bolts to the case and gives me a physical pointer right up to the ring gear face markers so that I know EXACTLY what the timing is. I should have made one of these long ago. It makes the entire effort safer, and more accurate. With this I can stand along side of the engine with the timing light and get very accurate readings. Remember, with these electronic ignitions, there is only ONE way to know that the timing really is, and thats with a timing light on the ring gear.

dealfair 01-24-2014 08:52 AM

Quote:

Originally Posted by Kahuna (Post 840481)
Ill get him on this. He has been recovering from a holiday of fishing with his boys. Thanks for reminding me.

Mike, I've really enjoyed following your story here. By chance, have you been able to chat with Jim B about his present opinion of running LOP???

Thank you and best regards,

Kahuna 01-24-2014 08:54 AM

Yes I have talked to him and he has expressed that he is not a LOP fan. Getting him to come here to discuss it has been difficult.

dealfair 01-24-2014 08:59 AM

OK, Thanks mucho Mike!

jthocker 01-24-2014 10:07 AM

Quote:

Originally Posted by Kahuna (Post 846800)
Yes I have talked to him and he has expressed that he is not a LOP fan. Getting him to come here to discuss it has been difficult.

Not to mention the fact, that Jimmy has a business to run, and getting into an internet discussion here would be a no win situation and would gobble up a huge amount of time!

hgerhardt 01-26-2014 01:02 PM

Don't pull the prop
 
Quote:

Originally Posted by Kahuna (Post 846772)
...the timing needs to be adjusted a bit. The bad news it that in order to do this, it's a complete prop pull...

No, it's not necessary to pull the prop to re-time the LSE crank trigger. I've done it on mine, with that same "REV 1" trigger board as Mike has. I'm not saying it's easy, but it is doable with less work than pulling the prop.

I use a right angle screwdriver to hold a 1/4" socket that I modified by bonding in a piece of 1/4" round stock (a sawed-off AN bolt works). I roughed up the end of the bolt to be bonded within the socket to keep it from spinning within the glue, but you don't want much torque for those small screws and the glue works well. Since the locking mechanism in the handle is a sprag clutch, it takes almost no movement of the handle to get useful rotation.

To see what you're doing, use a 2" dia inspection mirror.
Heinrich




Walt 01-26-2014 04:56 PM

If I remember correctly those LSI boards do not have any locking device for the board screws so a dab of loctite would be prudent. I added a locknut on the other side of the screw to ensure it couldn't come loose.


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