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Engine basics => Engine set up tips => Topic started by: Chris Fretz on April 27, 2016, 07:53:08 PM
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I picked up this LA46 an it looks a bit burnt, is this normal? By the looks of it to me it got pretty hot, still has great compression. I also noticed compared to my NIB LA46 the head look raised up significantly. I took the head off an it had 2 head gaskets on it but even with just one gasket it still looks raised up compared to the others. Any thoughts?
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I have one that looks about like that. Runs fine. You can consider cleaning it up (it'll cool better), or just run what you brung.
They had a long production run, and I suspect that many running changes were made along the way - that may account for the extra gap.
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If there is an extra shim in place, it looks sorta "tilted".......
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If there is an extra shim in place, it looks sorta "tilted".......
I noticed that too. I'd give you $10 for it, if you'll pay the postage and insurance. ;)
Seriously, I'd take it all apart and put it in the antifreeze/crockpot for at least 24 hours. Much of the paint will come off (a plus), all the varnish will come off the piston, and everything will be spiffy. NO PLASTIC goes in the antifreeze! Now that I think of it, I am wondering if that throttle is a stock one...I thought the stock LA ones are black plastic. It may be from an FP? Some NW Profile Sportsman Navy Carrier (is that enough adjectives?) flier may give you a pile of $ for it! If the removal of the varnish from the piston causes a reduction in compression, just run it a bit with some castor oil fuel and a big prop load for a few flights or bench runs. Or, send it to me! H^^ Steve
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One of my 46LAs came with a carb just like that. I think it's in the instruction manual, too.
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This is a sweet one. It has flown in several contests looking like this and going to another one tomorrow.
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Are the stock head gaskets .015 thick?
If there is an extra shim in place, it looks sorta "tilted".......
I think it's just the angle of the picture, looks even all the way around.
I noticed that too. I'd give you $10 for it, if you'll pay the postage and insurance. ;)
Seriously, I'd take it all apart and put it in the antifreeze/crockpot for at least 24 hours. Much of the paint will come off (a plus), all the varnish will come off the piston, and everything will be spiffy. NO PLASTIC goes in the antifreeze! Now that I think of it, I am wondering if that throttle is a stock one...I thought the stock LA ones are black plastic. It may be from an FP? Some NW Profile Sportsman Navy Carrier (is that enough adjectives?) flier may give you a pile of $ for it! If the removal of the varnish from the piston causes a reduction in compression, just run it a bit with some castor oil fuel and a big prop load for a few flights or bench runs. Or, send it to me! H^^ Steve
How about I'll just send you the motor an use your $10 to get you a gasket kit too <=
But I like the blue Steve... I'll end up kicking that carb to the curb an putting a venturi on it.
I have one that looks about like that. Runs fine. You can consider cleaning it up (it'll cool better), or just run what you brung.
They had a long production run, and I suspect that many running changes were made along the way - that may account for the extra gap.
I noticed different kind of plastic backplates on these.
This is a sweet one. It has flown in several contests looking like this and going to another one tomorrow.
That looks just like mine! #^
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This is a sweet one. It has flown in several contests looking like this and going to another one tomorrow.
I like your adjustable tank slide on that. I need to make one of those for my stupid Fox 35. Does it make a big difference on that LA46?
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I noticed that too. I'd give you $10 for it, if you'll pay the postage and insurance. ;)
Seriously, I'd take it all apart and put it in the antifreeze/crockpot for at least 24 hours. Much of the paint will come off (a plus), all the varnish will come off the piston, and everything will be spiffy. NO PLASTIC goes in the antifreeze! Now that I think of it, I am wondering if that throttle is a stock one...I thought the stock LA ones are black plastic. It may be from an FP? Some NW Profile Sportsman Navy Carrier (is that enough adjectives?) flier may give you a pile of $ for it! If the removal of the varnish from the piston causes a reduction in compression, just run it a bit with some castor oil fuel and a big prop load for a few flights or bench runs. Or, send it to me! H^^ Steve
It will look so much better as bare metal too!
Do you know if this paint responds to hot laundry detergent like most other paint does?
Phil
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I like your adjustable tank slide on that. I need to make one of those for my stupid Fox 35. Does it make a big difference on that LA46?
Absolutely, but make it with ply thicker than 1/16". As you can see in the picture, mine is bowed. I use a straight edge to align the edge of the tank between the first fins above the plug that aren't obstructed with the bolts. That was the magic position.
Since that picture was taken I have switched to a 6 oz. Sullivan clunk tank because I needed an extra 1/2 ounce for my heavy Cardinal. It was sucking air in the first loop of the Clover. I gave up trying to make a uniflow follower for the clunk in these, and just vent it like in the picture below, with the broad side against the profile. Muffler pressure to one of the vents and a cap on the other, which is used for fueling. And the engine runs right on song until the last lap. 5 oz. gets me the pattern and a few extra laps. I also switched to a an Eric Rule tongue muffler, added extra holes and a pressure tap. That OS-762 muffler(thanks Steve) in the first pic, with the stinger opened up wide is a nice little muffler too. I had a featherweight one that was ground eggshell thin all over, but it blew the back end off into the woods.
Rusty
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Well she ran fine on the bench.
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Absolutely, but make it with ply thicker than 1/16". As you can see in the picture, mine is bowed. I use a straight edge to align the edge of the tank between the first fins above the plug that aren't obstructed with the bolts. That was the magic position.
Since that picture was taken I have switched to a 6 oz. Sullivan clunk tank because I needed an extra 1/2 ounce for my heavy Cardinal. It was sucking air in the first loop of the Clover. I gave up trying to make a uniflow follower for the clunk in these, and just vent it like in the picture below, with the broad side against the profile. Muffler pressure to one of the vents and a cap on the other, which is used for fueling. And the engine runs right on song until the last lap. 5 oz. gets me the pattern and a few extra laps. I also switched to a an Eric Rule tongue muffler, added extra holes and a pressure tap. That OS-762 muffler(thanks Steve) in the first pic, with the stinger opened up wide is a nice little muffler too. I had a featherweight one that was ground eggshell thin all over, but it blew the back end off into the woods.
Rusty
Could you explain uniflow to me? Is that just one line feeding the engine and a vent line? What are the metal tanks with a feed line an a fill tube with a over flow tube called? An what's a uniflow follower? I've been making clunk tanks with a fill line that bent to the bottom of the tank and a vent line bent to the top of the tank along with the clunk feed line, is this wrong? I've also made clunk tanks lazily an just used a vent line bent to the top an filled it with the feed line. I see a lot of tank talk but don't understand what they are making or trying to achieve.
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Absolutely, but make it with ply thicker than 1/16". As you can see in the picture, mine is bowed. I use a straight edge to align the edge of the tank between the first fins above the plug that aren't obstructed with the bolts. That was the magic position.
Since that picture was taken I have switched to a 6 oz. Sullivan clunk tank because I needed an extra 1/2 ounce for my heavy Cardinal. It was sucking air in the first loop of the Clover. I gave up trying to make a uniflow follower for the clunk in these, and just vent it like in the picture below, with the broad side against the profile. Muffler pressure to one of the vents and a cap on the other, which is used for fueling. And the engine runs right on song until the last lap. 5 oz. gets me the pattern and a few extra laps. I also switched to a an Eric Rule tongue muffler, added extra holes and a pressure tap. That OS-762 muffler(thanks Steve) in the first pic, with the stinger opened up wide is a nice little muffler too. I had a featherweight one that was ground eggshell thin all over, but it blew the back end off into the woods.
Rusty
What is going on with the tank you took a picture of, why do you have what looks like 2 vent tube tubes soldered together? Do you use one to fill an one to vent?
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Could you explain uniflow to me? Is that just one line feeding the engine and a vent line? What are the metal tanks with a feed line an a fill tube with a over flow tube called? An what's a uniflow follower? I've been making clunk tanks with a fill line that bent to the bottom of the tank and a vent line bent to the top of the tank along with the clunk feed line, is this wrong? I've also made clunk tanks lazily an just used a vent line bent to the top an filled it with the feed line. I see a lot of tank talk but don't understand what they are making or trying to achieve.
Chris, please do yourself a favor, do a search on here for Uniflow,,, read especially anything from Brett, but there are some really good descriptions available.
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+1 what Mark said. I'd dive in, but I've been contest prepping and packing all day, and I'm shot.
Rolling out tomorrow and will post pics of the scoreboards, pretty planes and such as the weekend develops.
Rusty
What is going on with the tank you took a picture of, why do you have what looks like 2 vent tube tubes soldered together? Do you use one to fill an one to vent?
That's exactly what it is and how it works. One is muffler pressure(optional because I like a closed loop on the dry winter grass an open vent would inhale where I fly), the other is a fill tube, capped when running. Quick and simple. Rather than uniflow, it is what you could call standard vented or normally vented. For the way I run the LA, in a steady wet 2-stroke, it gets an even run throughout. A traditional 4-2 breaking stunt engine needs a steady head at the fuel feed to maintain a consistent run as the fuel level drops, and uniflow helps that happen. With your LA, a simple vent setup like mine will serve you well until you learn and choose your preferences as you advance. Don't try to emulate everything we tell you on the forums, just fly stunt and see what you like, and watch, listen and learn. At a point you'll know enough to cherry pick from all the advice that you begin to recognize as consistent. There are too many ways to get to the same place, and all the methods don't necessarily mix cooperatively.
See y'all after Stuntersville.
Rusty