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Engine basics => Engine set up tips => Topic started by: dave siegler on January 07, 2018, 06:36:34 AM
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I go my hands on a big art fp40 from a good guy that quit flying.
However, it looked bad inside. Not the brown castor bad, but the red rusty bad.
It inst all full of carbon.
Some air tool oil and a little WD for got it freed up nicely, and it has a real tight pinch at the top, so I am hopeful
I flushed it a few times and it is still red coming out.
I am tempted to just pull the back plate, head and flush it out and then run it. Real rich to clean it out.
There is no evince of dirt in it.
but think i need to strip it down.
What should my approach be here?
if it were a BB engine, for sure I would replace the bearings. but a bushing engine, I cant do much other than to see it is ruined already.
Also what was his rework? The venturi is HUGE. is is a 2-4-2 or a fast 4 cycle or what?
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If it has RUST in it, you should take it apart so you can get as much rust off of everything as possible, then clean really well lube and put it back together.
The rust that you do not get off or can't see can go thru the motor , when you run it and ruin things, as it is quite abrasive
Randy
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Thanks Randy...
By remove the rust. How? A little steel wool, or 1000 grit paper? or just get as much off as you can with a tooth brush and penetrating oil?
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Thanks Randy...
By remove the rust. How? A little steel wool, or 1000 grit paper? or just get as much off as you can with a tooth brush and penetrating oil?
Naval Jelly first.
Brett
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Rust is not as good an abrasive powder as carborundum, but it can be pretty effective. If you don't want to fill your engine with rubbing compound and run it, then don't run it with rust in it.
Before I read this thread I'd have taken it down completely (i.e. every screw unscrewed, liner out, piston pin out, etc. -- basically anything that can be done with hand tools), crock-potted it, then cleaned it with a toothbrush, soap & water, and maybe a toothbrush-sized wire brush before putting it back into service. Now that I've read the thread, I'd hit it with Naval Jelly, too.
If there's rust on any of the crank bearing surfaces I'd do two more things: one, I'd think about getting a new crank, depending on how much good material is left, and two, I'd worry about rust having embedded itself into the bearings in the case and the con rod. My one and only attempt at engine building wore out in the same run where it became broken in, because I didn't wash the lapping compound off of the piston well enough. So I'm kinda freaked out about stray abrasives left in an engine.
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If it is an early FP-40, then it has a steel liner and iron piston, correct? Rust can build up on those parts. The crank is also steel. If it is a later FP-40, the only steel component that will have rust is the crank. This engine is simple to dis-assemble and clean the crank with some tranny fluid and fine steel wool. If it's a iron version and you are a bit lazy, soak the whole thing in white vinegar for a day or two. White vinegar hates rust but won't bother steel. I learned this trick from a friend that hunts civil war relics. I clean steel tanks of rust on the inside with white vinegar and aquarium rocks and it works great. Doesn't work real fast but I don't think you want to be too aggressive.After it soaks, flush with some kind of solvent and bench run rich for a few tank fulls. Anything you can't flush out should at least be softened and will run through. A crock pot treatment in antifreeze will do the same thing. The anti rust additives in the antifreeze will soften the surface rust. I think the red stuff you saw flush out may have been congealed after run oil. I can't see one of those rusting that bad unless it was under water the whole time! I have taken McCoy .35 red heads with some slight surface rust, crock potted them and then flushed with fuel and flown with no problems.
Good luck and have fun!
Type at you later,
Dan McEntee
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the date on the rework is 1983. it looks like the late model one though, it has the bump on the bypass.
I will toss this in the crock pot. I have a few engines to dip.
it might be run after oil, but it is rely red.
I have received some real ugly engines, but never this color red, most are more brown and black.
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This is one of the cases where taking it apart completely seems warranted, derust each part, remove any trace of particles, crock-pot the rest, re-assemble using 0W40 synthetic motor oil, and then run it. It's pretty darn simple as engines go.
Brett
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Dave The crank is not the only thing you have to worry about, the wrist pin is steel, and will rust and lock up, so pay attention to this, the crank needs all the rust off of it, and then what I do is spin it on a lathe, or drill, and polish the surface with 1000 grit paper and oil. Just take a few seconds to do that
You will also find many times the aluminum oxidizes , sometime badly, so get that off too , Aluminum OXIDE is BAD for the motor, They make sandpaper out of it.
Let me know if you need replacement parts, but hopefully you can clean it all up and it will run well.
I am skeptical about the hard pinch at the top, that sound like rust and alum debris , as OS did NOT make any of these with a hard pinch, embedded rust an oxide debris in the piston can make the pinch tighter, but will instantly kill the liner when ran
Randy
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The one detail that needs to be watched for on re-assembly is the cylinder alignment pin. Also, I believe Big Art FP's had blocked boost ports, but I've never seen one. If he used JB Weld to do that, it will probably come out in the crockpot. y1 Steve
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I digested a FP 40 from just some oxidation on the crank web .
You should dismantle , clean , and send to ME . ;D
Or Photograph & measure ' all the tricks ' and put HERE for posterity .
Found the spay Brake Cleaner I had broke down the carbon buildup up inside the piston , tho still took a bit of scrapeing .
1200 Wt Wet & Dry on flat surface polished crank , big end & gudgeon ( wrist ) pin . Nicely . Bit time consumeing .
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The Piston and Cylinder are toast.
I just got it apart and there is a big chunk of the plating on the liner that flaked off.
This appears to t be a preexisting condition, as it corroded where the plating used to be.
I think I can clean up the rest of it and use it as a parts engine.
I can see try the plugged boost port and the bushed rod drilled for oil holes. but I don't know what else he did to the engine.
I have a couple of NIB FP and LA 40's so the needle valve, venturi and the metal back plate, case, head drive washer, crank will be nice.
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Dave,
Get a Tower 40 and use the P/L in your FP 40. They are ABC and fairly cheap on eBay.
Cheers, Jerry
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Hi all.
I go with Gerald recommendations. I wore out a retimed by me P/L of a Magnum 40GP (OS 40 FP clone) in Only a season. Bought in Tower a Tower 40 PL (true ABC), retimed for stunt and after three times the use of the GP, is still going....... good investment.
Regards.
Manuel.
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:DBe intresting to know the differance in the hight of the top of the ports in the sleeve . Tho the trans is probably tapered upward ..
Your saying it has a bunged center / boost port ??
they recon the plateing dematerialises with the wrong oil. Can remeber wott they said was the right oil , think it was they need some castor,
particularly with the plain bush crank set up .
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So other than rob this for parts, what can I do with this engine?
Can I get measurements off the sleeve and transfer this to a new engine?
I don't have a lot of money in it. So it's ok.