DL-50 engine
10-15-2009, 07:13 PM
#5827
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RE: DL-50 engine
ORIGINAL: JoeAirPort
Actually it doesn't. Mine were bent way more than that....
Awesome idea BTW. [8D]
Aren't you going to heat that bolt up first?
Actually it doesn't. Mine were bent way more than that....
Awesome idea BTW. [8D]
Aren't you going to heat that bolt up first?
The bolt came off w/o issues. Now the most challenging part is to determine the cause of the wobbling. I think I need to get a dial indicator.
10-15-2009, 08:32 PM
#5829
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RE: DL-50 engine
ORIGINAL: PlaneKrazee
Good idea with the landing gear! Did you find any play in the propdriver? If not, it may be a bent crank.
Good idea with the landing gear! Did you find any play in the propdriver? If not, it may be a bent crank.
Crank is straight as an arrow as far as I can see and my eyes are pretty good 20/20 and 15/20.
It's the prop hub. If I put the backplate of the spinner on, take a reference point, and turn the shaft, I can see the plate going up/down. Just a tiny bit. I managed to correct most of it with a hammer
(by supporting the center of the shaft so w/o putting any load on the bearings). A possibility is that over time the center hole of the hub wears out a bit because of different bolt tensions, prop not drilled exactly 90 degrees and so on. So I need a new prop hub assembly.http://www.thunderboltrc.com/index.p...roducts_id=262 Jody please?
If I manage to get rid of the clicking sound which I think is just a matter of cleaning the cylinder head from any carbon, it'll be safe to fly until I get the new hub in? If I don't fly this bird tomorrow I get serious withdrawal symptoms.
10-15-2009, 08:57 PM
#5831
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RE: DL-50 engine
I have been wanting to ask you if the piston has only one direction it should be installed into the clyinder. I know that your ring land on some cly determines which way the piston should be installed and if you get it backwards the ring will pop in and out of the ports untill it breaks and then ouch. I have'nt been into my DL but have on others and I know it sometimes makes a difference.
10-15-2009, 08:58 PM
#5832
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RE: DL-50 engine
ORIGINAL: JoeAirPort
It just bugs me why you have that clicking sound now but not with the other piston (can't actually remember what's all new).
It just bugs me why you have that clicking sound now but not with the other piston (can't actually remember what's all new).
Jody thinks differently, I think it's the piston hitting the head and some carbon cleanup will do the trick. All bearings are fine and the only thing that can click is the piston ring and that's the click you usual hear. Don't forget we're still talking about a Chinese engine and margins might differ slightly amongst engines.
10-15-2009, 09:00 PM
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RE: DL-50 engine
ORIGINAL: FOOPED
I have been wanting to ask you if the piston has only one direction it should be installed into the clyinder. I know that your ring land on some cly determines which way the piston should be installed and if you get it backwards the ring will pop in and out of the ports untill it breaks and then ouch. I have'nt been into my DL but have on others and I know it sometimes makes a difference.
I have been wanting to ask you if the piston has only one direction it should be installed into the clyinder. I know that your ring land on some cly determines which way the piston should be installed and if you get it backwards the ring will pop in and out of the ports untill it breaks and then ouch. I have'nt been into my DL but have on others and I know it sometimes makes a difference.
There's an arrow on the piston that should face the exhaust and the piston has 2 intake ports on only just one side. The engine will run very poorly if the piston was turned 180 degrees.
10-15-2009, 09:05 PM
#5834
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RE: DL-50 engine
Thanks for the reply I will keep that in my head so when and if I ever tear into mine I will be ahead of the game. Watching close to see what you find out.
10-15-2009, 09:09 PM
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RE: DL-50 engine
My original DL prop hub had a layer of locktite type material almost as think as a fingernail on one side. Mine was an early engine. If they don't hold the tolerances tight enough they can reall stack up, ie; small shaft, large driver bore.
10-15-2009, 09:46 PM
#5838
RE: DL-50 engine
ORIGINAL: mstam1971
Thanks. I still have the prop hub assembly not running in the center so I'll disassemble it.
Will take the plug out and see if it blocks anywhere. What I noticed is that one half of the cylinder head is completely clear from carbon and I have a blank spot on the piston, see image.
I checked the cage roller really well by turning the crank slowly and couldn't find any irregularities. Also the front and rear bearing seem to be in perfect shape.
TBC...
And unit53, yes I could send it in but Jody would have to go through the same procedure and the last missing tool is the piece of metal to hold the prop hub. I always mount my hardware to outlast the frame of the plane and I can do this repair w/o taking the engine from the stands, and taking off the choke and throttle linkages, and I still have the header in place on the cylinder. Messing w/ the header too much can eventually cause it to start leaking, stripped threads etc. Now I only need to replace the cylinder gasket. And I think something is wrong with the prop bolt. I'll find out soon.
ORIGINAL: jedijody
Martin, the piston cannot hit the top of the head, it's probably hitting the piece of bearing cage or roller that got left in the engine after the initial repair. You should be able to feel this as you turn the engine over with out the spark plug installed, as the piston comes to TDC you will feel slight resistance then with a little more pressure it will go over TDC. If the crankshaft bearings feel tight, there is no end play in the crankshaft, and there is nothing leaking from the main bearings, you should not need to remove the prop hub or crankshaft. I would carefuly inspect the bearing on the big end of the rod by using some magnification and turning the bearing around the crank throw with a small screw driver through the oil slot in the rod. If anything looks marginal continue with the disassembly.
Martin, the piston cannot hit the top of the head, it's probably hitting the piece of bearing cage or roller that got left in the engine after the initial repair. You should be able to feel this as you turn the engine over with out the spark plug installed, as the piston comes to TDC you will feel slight resistance then with a little more pressure it will go over TDC. If the crankshaft bearings feel tight, there is no end play in the crankshaft, and there is nothing leaking from the main bearings, you should not need to remove the prop hub or crankshaft. I would carefuly inspect the bearing on the big end of the rod by using some magnification and turning the bearing around the crank throw with a small screw driver through the oil slot in the rod. If anything looks marginal continue with the disassembly.
Will take the plug out and see if it blocks anywhere. What I noticed is that one half of the cylinder head is completely clear from carbon and I have a blank spot on the piston, see image.
I checked the cage roller really well by turning the crank slowly and couldn't find any irregularities. Also the front and rear bearing seem to be in perfect shape.
TBC...
And unit53, yes I could send it in but Jody would have to go through the same procedure and the last missing tool is the piece of metal to hold the prop hub. I always mount my hardware to outlast the frame of the plane and I can do this repair w/o taking the engine from the stands, and taking off the choke and throttle linkages, and I still have the header in place on the cylinder. Messing w/ the header too much can eventually cause it to start leaking, stripped threads etc. Now I only need to replace the cylinder gasket. And I think something is wrong with the prop bolt. I'll find out soon.
You can't inspect the rod bearing by rotating the crankshaft, hold the crankshaft near TDC and lay the rod over to the side then use a very small srewdriver through the oil slot in the rod to rotate the bearing on the rod throw, use magnification to check the bearing for anomalies or for any foriegn matter in the rollers, unless you have binocular vision yours isn't good enough.
10-15-2009, 09:51 PM
#5839
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RE: DL-50 engine
there are several ways,to remove the hub, but ,i can see that mtsam is a mc guiver for sure and is a good improviser,im hoping he gets it repaired as well,besides a few beautiful women,,this is the kind of guy one would need on a deserted island,he would certainly get us home.
10-15-2009, 10:14 PM
#5840
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RE: DL-50 engine
Guys, here's a link to earlier posts in this thread that describes everything you need to know about disassembling and assembling this engine. I've done it twice now (to repair damaged bearings/case from crashes). I consider my self a DL50 expert now (but I'm probably not really).
http://www.rcuniverse.com/forum/fb.asp?m=7920688
Also, here are the same instructions written in my own words:
DL 50 Engine Assembly Instructions
(Originally written by dlenginesaustralia)
I. Preparation/Assembly Notes:
Loctite 620 Bearing Mount (High Temp) is required to securely mate the bearings to the crank shaft and to the crank case (and other parts as instructed). Bearing Mount can be purchased or ordered in small quantities (5ml – 15ml) for as little as $5.00 - $15.00 from ball bearing retailers.
Protect your workbench and engine parts by working over a sheet of cardboard or other barrier.
Clean all parts thoroughly for easier assembly and best adhesion of Bearing Mount.
Do not use excessive Bearing Mount. Do not apply until ready to fit the parts. As you proceed, remove excess Bearing Mount with cloth.
Keep all tools within reach so you can work quickly while parts are still hot.
Wear leather gardening gloves when handling heated parts.
II. Crank Installation
1. Place front crank case half, rear bearing and propeller hub into oven heated to 280F.
2. After about ten minutes, working quickly, remove case from oven, apply Bearing Mount to case and outer race of front bearing. Install front bearing into case.
3. Replace front case/bearing assembly in oven to re heat for installation of crank shaft/rear bearing assy.
4. Working quickly again, remove rear bearing from oven, apply Bearing Mount to inner race of rear bearing and crank shaft. Tap bearing onto crank shaft with 15 – 16mm I.D. pipe applying pressure only to inner race of bearing—do not apply pressure to bearings, seal or outer race.
5. Install aluminum bearing spacer onto crankshaft.
6. Working quickly once more, remove front case/front bearing assy. from oven. Apply Bearing Mount to outer race of rear bearing and in case for rear bearing. Install crank/rear bearing assy. into case. Allow everything to cool.
III. Hub Installation
1. Apply Bearing Mount to woodruff key and crank shaft. Install key into crank shaft.
2. Remove propeller hub from oven. Turn off oven. Proceed immediately to the next step.
3. Working quickly and supporting center of crank assy. with hardwood dowel or similar (so as to keep force centered on crank shaft—not on con rod/counterbalance), lightly tap heated hub onto crank assy. just far enough to expose crank threads so prop shaft can be fitted.
4. If necessary, apply more heat to hub (using heat gun), then use a tool to hold hub while tightening prop shaft drawing hub the rest of the way down.
IV. Final Assembly
1. Install piston, wristpin, bearing and wristpin clips to con. rod. Be certain wrist pin clips are fully seated and the “tails†of the clips do not have any nicks in them which could cause them to break off inside the engine.
Note: The arrow stamped into the top of the piston points toward the exhaust. The anti-rotation pin in the ring groove is located opposite the exhaust.
2. Join the case halves using a thin film of gasket sealer or the Loctite Bearing Mount used for bearing installation (which is thin, fuel proof and normally sufficient—if desired, Loctite 518 or 573/4 could also be used, but usually not necessary due to the good fit of the case halves).
3. Apply a drop of blue Loctite to the case bolts. Tighten evenly in a standard chris-cross pattern.
4. Lightly oil all parts including the piston ring and cylinder walls—the two-cycle premix oil you have been running your engine with is suitable.
5. Compress the piston ring with your fingers while sliding the piston into the cylinder.
6. Tighten the cylinder to the case halves with blue Loctite on the bolts.
http://www.rcuniverse.com/forum/fb.asp?m=7920688
Also, here are the same instructions written in my own words:
DL 50 Engine Assembly Instructions
(Originally written by dlenginesaustralia)
I. Preparation/Assembly Notes:
Loctite 620 Bearing Mount (High Temp) is required to securely mate the bearings to the crank shaft and to the crank case (and other parts as instructed). Bearing Mount can be purchased or ordered in small quantities (5ml – 15ml) for as little as $5.00 - $15.00 from ball bearing retailers.
Protect your workbench and engine parts by working over a sheet of cardboard or other barrier.
Clean all parts thoroughly for easier assembly and best adhesion of Bearing Mount.
Do not use excessive Bearing Mount. Do not apply until ready to fit the parts. As you proceed, remove excess Bearing Mount with cloth.
Keep all tools within reach so you can work quickly while parts are still hot.
Wear leather gardening gloves when handling heated parts.
II. Crank Installation
1. Place front crank case half, rear bearing and propeller hub into oven heated to 280F.
2. After about ten minutes, working quickly, remove case from oven, apply Bearing Mount to case and outer race of front bearing. Install front bearing into case.
3. Replace front case/bearing assembly in oven to re heat for installation of crank shaft/rear bearing assy.
4. Working quickly again, remove rear bearing from oven, apply Bearing Mount to inner race of rear bearing and crank shaft. Tap bearing onto crank shaft with 15 – 16mm I.D. pipe applying pressure only to inner race of bearing—do not apply pressure to bearings, seal or outer race.
5. Install aluminum bearing spacer onto crankshaft.
6. Working quickly once more, remove front case/front bearing assy. from oven. Apply Bearing Mount to outer race of rear bearing and in case for rear bearing. Install crank/rear bearing assy. into case. Allow everything to cool.
III. Hub Installation
1. Apply Bearing Mount to woodruff key and crank shaft. Install key into crank shaft.
2. Remove propeller hub from oven. Turn off oven. Proceed immediately to the next step.
3. Working quickly and supporting center of crank assy. with hardwood dowel or similar (so as to keep force centered on crank shaft—not on con rod/counterbalance), lightly tap heated hub onto crank assy. just far enough to expose crank threads so prop shaft can be fitted.
4. If necessary, apply more heat to hub (using heat gun), then use a tool to hold hub while tightening prop shaft drawing hub the rest of the way down.
IV. Final Assembly
1. Install piston, wristpin, bearing and wristpin clips to con. rod. Be certain wrist pin clips are fully seated and the “tails†of the clips do not have any nicks in them which could cause them to break off inside the engine.
Note: The arrow stamped into the top of the piston points toward the exhaust. The anti-rotation pin in the ring groove is located opposite the exhaust.
2. Join the case halves using a thin film of gasket sealer or the Loctite Bearing Mount used for bearing installation (which is thin, fuel proof and normally sufficient—if desired, Loctite 518 or 573/4 could also be used, but usually not necessary due to the good fit of the case halves).
3. Apply a drop of blue Loctite to the case bolts. Tighten evenly in a standard chris-cross pattern.
4. Lightly oil all parts including the piston ring and cylinder walls—the two-cycle premix oil you have been running your engine with is suitable.
5. Compress the piston ring with your fingers while sliding the piston into the cylinder.
6. Tighten the cylinder to the case halves with blue Loctite on the bolts.
10-15-2009, 11:00 PM
#5841
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RE: DL-50 engine
ORIGINAL: jedijody
The picture of the piston has a bunch of tiny silver dots on the top of the intake side near the area that is circled, these look like small dents from FOD. Look at them very closely.
You can't inspect the rod bearing by rotating the crankshaft, hold the crankshaft near TDC and lay the rod over to the side then use a very small srewdriver through the oil slot in the rod to rotate the bearing on the rod throw, use magnification to check the bearing for anomalies or for any foriegn matter in the rollers, unless you have binocular vision yours isn't good enough.
The picture of the piston has a bunch of tiny silver dots on the top of the intake side near the area that is circled, these look like small dents from FOD. Look at them very closely.
You can't inspect the rod bearing by rotating the crankshaft, hold the crankshaft near TDC and lay the rod over to the side then use a very small srewdriver through the oil slot in the rod to rotate the bearing on the rod throw, use magnification to check the bearing for anomalies or for any foriegn matter in the rollers, unless you have binocular vision yours isn't good enough.
10-15-2009, 11:34 PM
#5842
RE: DL-50 engine
ORIGINAL: mstam1971
Think you are right. Looks like little dents to me. See image.
ORIGINAL: jedijody
The picture of the piston has a bunch of tiny silver dots on the top of the intake side near the area that is circled, these look like small dents from FOD. Look at them very closely.
You can't inspect the rod bearing by rotating the crankshaft, hold the crankshaft near TDC and lay the rod over to the side then use a very small srewdriver through the oil slot in the rod to rotate the bearing on the rod throw, use magnification to check the bearing for anomalies or for any foriegn matter in the rollers, unless you have binocular vision yours isn't good enough.
The picture of the piston has a bunch of tiny silver dots on the top of the intake side near the area that is circled, these look like small dents from FOD. Look at them very closely.
You can't inspect the rod bearing by rotating the crankshaft, hold the crankshaft near TDC and lay the rod over to the side then use a very small srewdriver through the oil slot in the rod to rotate the bearing on the rod throw, use magnification to check the bearing for anomalies or for any foriegn matter in the rollers, unless you have binocular vision yours isn't good enough.
10-15-2009, 11:41 PM
#5844
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RE: DL-50 engine
ORIGINAL: jedijody
Ah ha! So I do know my ***** from a hole in the ground.
Ah ha! So I do know my ***** from a hole in the ground.
W/o your help my engine would have been converted into a meat grinder any time soon.When you wake up, please call me for my CC info, see ismiami dot com for phone number, or I'll call you at around 10 AM your time.
For the following:
crankshaft kit
bearing kit
propeller hub kit
cylinder gasket
Does someone know a local store that carries Loctite 620? Else I'll order online.
Thank you all for your help!
10-16-2009, 06:58 AM
#5847
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RE: DL-50 engine
Regarding VELOCITY STACKS. Some engine manufacturers put them on, others do not. What is the verdict? Are they of any benefit? Should I bother to get one?
10-16-2009, 08:05 AM
#5848
RE: DL-50 engine
After having one solve mixture problems at changing attitudes on my DL-50 I put one on my DLE-55 right out of the box. They both run the same, identical...and that's awesome. No more fuel spraying all over the engine box. That was a nice surprise. Now would I say to everyone they need one? No. I just found that they clean up the air stream coming into the carb and I feel they make for a very efficient mixture. I like how clean the engine box is, bone dry. And they cost only a few bucks. I have room for them on my two planes (go through the hole in the firewall). For me it's a standard part on my engines. I just can't believe how inexpensive they are and how easy to install. The easiest mod I have done to any gasser. The carb plate vent mod might be a little easier....both easy. They both makes for some very consistant running engines. When you're doing 3D stuff inches off the deck you need all the help you can to keep the engine running. So far neither of these engines has let me down in a year of flying like this. Can you tell I like my DL/DLE engines? (Thanks to Jody @ ValleyviewRC.com who helped me quite a bit).
Edit: These mod's do not solve the problem of an engine that just needs tuning. Tune it first then decide if you need the mod's.
Edit: These mod's do not solve the problem of an engine that just needs tuning. Tune it first then decide if you need the mod's.
10-16-2009, 08:19 AM
#5849
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RE: DL-50 engine
Ok, so is the velocity stack the mod you guys have been talking about where you drill a hole in the carb plate, mount a copper tube and run a fuel line tinto the fuse to help stabilize the air? if so , how do i solder the tube onto the plate without distorting the plate ?
10-16-2009, 08:39 AM
#5850
RE: DL-50 engine
ORIGINAL: hillbillyexpress
Ok, so is the velocity stack the mod you guys have been talking about where you drill a hole in the carb plate, mount a copper tube and run a fuel line tinto the fuse to help stabilize the air? if so , how do i solder the tube onto the plate without distorting the plate ?
Ok, so is the velocity stack the mod you guys have been talking about where you drill a hole in the carb plate, mount a copper tube and run a fuel line tinto the fuse to help stabilize the air? if so , how do i solder the tube onto the plate without distorting the plate ?
You can thread that vent hole with an 8-32 tap and put a barb fitting on with red lock tite (or anything permanent). You can also solder it on. Grind off the threads sticking out on the inside. Or you can also just solder a brass tube onto the plate. It won't distort anything. Take the plate off the carb of course. Just electronic soldering is fine. Never done it myself as I wasn't confident in my soldering. I like the threads holding the fitting with the lock tite. Next time I'll probably do the 8-32 barb fitting and try soldering it on.
These pic's show both mod's. The v-stack just uses the same two bolts that hold the carb and reed block on.
PS: Notice the NGK CM-6 plug in one of those engine pic's? heh heh...right out of the box they get 'em.