12LikesStrange black goop forming in my new Picco engine
03-25-2020, 09:34 PM
#1
Strange black goop forming in my new Picco engine
I've been running the same fuel for years (Byron's Gen2 30% nitro / 11% oil, spiked with 50mL of extra castor oil per gallon), and my engines generally develop a faint brownish-gold color on the top of the piston and the underside of the cylinder-head after a few months of use. But my new Picco P12 engine has these weird black droplets of hardened goop forming on the top of the piston. What might be causing this?
03-26-2020, 02:00 AM
#2
You should have cleaned the engine. It was an old model so the oil inside was also old. Take off the backplate and inspect it is just dryed up oil or rust.
03-26-2020, 03:41 AM
#3
I always completely disassemble new engines so I can remove burrs on the edges of sleeve ports, or loose metal shavings, or fix any other problems that might exist. Then I wash the parts and re-oil everything with after-run oil before assembly. There was no old oil left inside this engine.
I also open the engine after the first run, and I wipe the sides of the sleeve with a cotton swab to remove any chrome flakes that came loose during the first run. I check again after each of the first 5 runs, just to be sure. That's why I had the engine open and saw this black goop forming on the top of the piston.
I also open the engine after the first run, and I wipe the sides of the sleeve with a cotton swab to remove any chrome flakes that came loose during the first run. I check again after each of the first 5 runs, just to be sure. That's why I had the engine open and saw this black goop forming on the top of the piston.
03-26-2020, 07:18 AM
#5
03-26-2020, 08:14 AM
#6
As I di mention, must be old oil from assembling. Probably from the main bearing.
03-26-2020, 01:04 PM
#7
I have a quart bottle of Cool Power degummed castor oil that I've been slowly using-up for years. It's pretty old, but it's been old for a while, and I haven't seen these deposits forming before. Also they're only forming in this one engine, so it must be something about the construction or configuration of this engine that's causing it.
Now that I think a bit more about what Roelof said: This is the only engine I own that has the pullstart bearing inside the crankcase. I oiled the pullstart bearing during my initial inspection, but I didn't check if there was old grease in the bearing, because all my other engines have the pullstart bearings outside the crankcase so it doesn't matter if those pullstart bearings have old grease in them. I bet there was old grease in the pullstart bearing and it's slowly dissolving and being burned in the combustion chamber. It would be a strange oversight by Picco to assemble an engine with an internal pullstart bearing that wasn't degreased prior to installation, but...oh well.
Now that I think a bit more about what Roelof said: This is the only engine I own that has the pullstart bearing inside the crankcase. I oiled the pullstart bearing during my initial inspection, but I didn't check if there was old grease in the bearing, because all my other engines have the pullstart bearings outside the crankcase so it doesn't matter if those pullstart bearings have old grease in them. I bet there was old grease in the pullstart bearing and it's slowly dissolving and being burned in the combustion chamber. It would be a strange oversight by Picco to assemble an engine with an internal pullstart bearing that wasn't degreased prior to installation, but...oh well.
03-30-2020, 01:18 AM
#8
Could also be too much oil in the fuel. 11% is enough so not sure why you are then adding more.... but then again Picco engines are pretty poor quality and so perhaps it needs that extra oil to stay together.
03-30-2020, 02:37 AM
#9
I can't say I've ever heard someone dis Picco before. My first nitro engine was a Picco and it survived my nitro-noob "lean it out until I get the power I want, regardless of consequences" phase quite well. But your list of vehicles makes it pretty clear you're a brand loyalist, so I'm guessing you would think Picco engines are garbage simply because they aren't Novarossis even if you'd never used one before.
I add a little bit of castor oil to my fuel partly because a tiny amount of castor varnish improves the sealing and lubricity of the piston and cylinder walls, partly because higher oil content increases engine lifespan, partly because I like tinkering with things, and partly because why the hell not.
I add a little bit of castor oil to my fuel partly because a tiny amount of castor varnish improves the sealing and lubricity of the piston and cylinder walls, partly because higher oil content increases engine lifespan, partly because I like tinkering with things, and partly because why the hell not.
03-30-2020, 03:54 AM
#10
For sure the onroad racing engines have a short lifespan, within a few liters of use many people experience a worn out P/S set. One of the reasons is the very low pinch in new condition which Picco use. The break in can be done with 1 or 2 tanks and with that it will not build a wide contact spot on the side of the piston. The wider that contact spot (the shown blank ring when runned some tanks) the longer the life of the set.
Last edited by Roelof; 03-30-2020 at 08:22 AM.
03-30-2020, 12:43 PM
#11
I can't say I've ever heard someone dis Picco before. My first nitro engine was a Picco and it survived my nitro-noob "lean it out until I get the power I want, regardless of consequences" phase quite well. But your list of vehicles makes it pretty clear you're a brand loyalist, so I'm guessing you would think Picco engines are garbage simply because they aren't Novarossis even if you'd never used one before.
I add a little bit of castor oil to my fuel partly because a tiny amount of castor varnish improves the sealing and lubricity of the piston and cylinder walls, partly because higher oil content increases engine lifespan, partly because I like tinkering with things, and partly because why the hell not.
I add a little bit of castor oil to my fuel partly because a tiny amount of castor varnish improves the sealing and lubricity of the piston and cylinder walls, partly because higher oil content increases engine lifespan, partly because I like tinkering with things, and partly because why the hell not.
03-30-2020, 07:32 PM
#12
I have noticed that Picco engines have very weak pinch, but I always assumed that was because they machined the piston closer to its final broken-in shape to begin with, so less break-in is necessary. I wonder if the weak pinch causes people to treat Picco engines differently during break-in, which might affect their lifespan. Certainly the more carefully an engine is broken-in the longer it will last before needing a rebuild, so if people assume Picco engines require shorter break-in periods because the pinch is weaker, that could cause Picco engines to wear-out faster. I've driven this engine for at least 10 tanks now and I'm still slowly leaning-out the fuel mixture to bring the engine up above 200°F; I get the impression it will always be a cold-running engine, because it's already producing excellent power (for a side-exhaust engine) at this point.
Anyway, it was really obvious that Dan was being a fanboy and was primarily interested in scoring a cheap shot with his comment, hence the terseness of my reply.
Anyway, it was really obvious that Dan was being a fanboy and was primarily interested in scoring a cheap shot with his comment, hence the terseness of my reply.
Last edited by fyrstormer; 03-30-2020 at 07:47 PM.
03-31-2020, 01:24 AM
#13
I have runned Picco twice because I did like the price and performance and quickly stayed away of them. A much more carefull break in does not help because the microscopic rough surface of the piston is not compleetly polished flat and so still remains weak
03-31-2020, 07:34 AM
#14
I have noticed that Picco engines have very weak pinch, but I always assumed that was because they machined the piston closer to its final broken-in shape to begin with, so less break-in is necessary. I wonder if the weak pinch causes people to treat Picco engines differently during break-in, which might affect their lifespan. Certainly the more carefully an engine is broken-in the longer it will last before needing a rebuild, so if people assume Picco engines require shorter break-in periods because the pinch is weaker, that could cause Picco engines to wear-out faster. I've driven this engine for at least 10 tanks now and I'm still slowly leaning-out the fuel mixture to bring the engine up above 200°F; I get the impression it will always be a cold-running engine, because it's already producing excellent power (for a side-exhaust engine) at this point.
Anyway, it was really obvious that Dan was being a fanboy and was primarily interested in scoring a cheap shot with his comment, hence the terseness of my reply.
Anyway, it was really obvious that Dan was being a fanboy and was primarily interested in scoring a cheap shot with his comment, hence the terseness of my reply.
03-31-2020, 08:00 PM
#15
No it wasn't obvious, he was providing accurate information, you just think you know better than people that have been racing for decades. Racing is so far removed from bashing, it would surprised you. In racing every motor is tuned for maximum performance, which exposes the weaknesses and one of Piccos weakness is longevity. I've run Picco, Nova, Max, and O.S.. I used to run the Picco JL .12, the thing was ballistic, but it would be worn out by the time it needed a new rod, price was really good though. You've been told before, don't make comparisons between your running and racing, they don't compare.
And this part was a cheap shot:
And it doesn't even make sense. Oil doesn't hold engines together.
[impolite comments deleted] Anyway, I'm pretty sure the mystery has been solved, so let's all walk away now.