Older OS engine eating glow plugs
01-30-2021, 01:44 PM
#1
Thread Starter
Older OS engine eating glow plugs
Hi all. Long time coming back into hobby. I have a 16 year old hpi on road car with a 15 year old OS Max 18CV-r series engine it. Getting it restarted today and went through 4 glow plugs with the filament being bent up inside the plug.
I reset engine to factor specs. Used brand new 20% nitro but only 9% oil. Manual says to use nothing less than 18% lubricant. In the past, 2 years ago it was running fine but wasn’t sure what fuel I had at the time. Very little smoke coming out at factory startup settings. I’m wondering from those here is the oil content too low? What could cause 4 plugs to be bent and go bad? It would fire up and idle fine and run a bit, not at great power since seemed to be rich, but once it died I removed the plugs and they all had gone bad. Using prob 15 year old os8 plugs in it. Open to any help!
I reset engine to factor specs. Used brand new 20% nitro but only 9% oil. Manual says to use nothing less than 18% lubricant. In the past, 2 years ago it was running fine but wasn’t sure what fuel I had at the time. Very little smoke coming out at factory startup settings. I’m wondering from those here is the oil content too low? What could cause 4 plugs to be bent and go bad? It would fire up and idle fine and run a bit, not at great power since seemed to be rich, but once it died I removed the plugs and they all had gone bad. Using prob 15 year old os8 plugs in it. Open to any help!
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franchi (02-17-2021)
02-03-2021, 09:12 AM
#4
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Inspect the bearing cage on the rear bearing. They come apart gradually and introduce little pieces of shrapnel into the cylinder. I ignored the initial sign (mangled glow plug element) on one of my engines and continued running it with a new glow plug. A short time later the engine seized in flight. A larger chunk of the cage had wedged between the piston and one of the ports. The engine was ruined.
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franchi (02-17-2021)
02-04-2021, 08:06 AM
#7
A bit late here. Bent coil is usually too high compression. Vapourised coil is too lean. I would add a shim to the head and richen it a bit assuming bearings and other things mentioned are OK. Once the coil is vapourised a few times the powder on top of the piston and head will need to be cleaned off or it will blow more plugs too.
