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Engine basics => Engine set up tips => Topic started by: Paul Taylor on November 03, 2006, 08:02:31 PM
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I am in the process of breaking in a Veco .19.
When I run the engine fuel seems to flow from the front bearing. Not a lot but you can see it drip from the front of the engine.
I let it run about 1oz of fuel then shut it down to cool.
Using 5/29 Lou's Brew fuel.
Is this fuel leaking a bad thing?
Thanks
Paul
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I don't remember seeing a reply when you were asked if it was a ball bearing engine or not. If it is a ball bearing engine you should be able to fix the dripping by replacing the front bearing. If it has a bronze bearing then it is normally lubed by pressure from the crank pushing the fuel toward the front of the shaft. If the engine runs well and the dripping is not too severe I wouldn't much worry about it. I would however use a fuel with a lot of castor oil.
AP^
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Remember, the lube for the front bearing is suppplied by this leakage. The amount of leakage depends on the fit between the crankshaft and the crankcase housing (between the two bearings). Some engines have a grooves which try to pump the oil back towards the venturi, but I have no idea if the Veco 19 has that.
Honestly, you shouldn't worry so much about a little leaking (especially if it is mounted on a profile)?. A lot more gunk is blowing out the exhaust. The only bad thing is if it compromises the crankase pressurization that pumps the fuel mixture up into the cylinder.
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Paul,
I have seen several engines with front bearings that leak a little fuel. Most of my R/C engines use bearings with rubber seals for the front--this stops the leak. On some, the seal is removed on one side of the bearing and the bearing is installed with the rubber seal towards the prop.
If the leakage on your engine is only an occasional drop or so, I wouldn't worry about it. You can install a sealed front bearing when you replace the present bearings.
On the YS 61 Long Stroke engines I have, some came with a sealed front bearing, however when I got replacement bearings from YS, the front bearings were not sealed.
A fix which the YS factory used to stop the leak with unsealed bearings was to drill a small (.020 to .030 in.) hole from the front of the bearing seat back into the air intake passage. This allowed the venturi suction to draw the excess fuel back into the engine intake. This became a standard mod for YS 61 engines of the early production runs.
I don't know enough about the Veco 19 to recommend drilling this hole in your engine but some one else may be able to comment.
Jim Oliver
PS--I am at my daughter's home in LA at the moment, hence, the Regina Kelly name.
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Hi Paul,
Like the others have said, the leak, if just a few drops, is ok.
I remember the picture you posted as being a ball bearing engine. I would eventually put replacements from Boca Bearings in it and cure the problem all together. I got their standard replacements for an OLD one of mine (bought it in '72) which I had never run. No leakage since their bearings have a front seal. I had to remove the rear seal onthe front bearing according to their instructions and it took all of about 10 seconds to get it off. The front seal stayed in place.
Like I've said before, I think they are great .19 size engines, and when I get my plans built Stering Yak 9 finished, I will be using the Veco .19 BB in OTS.
I have some old wood 10-4s that I am going to start with, and depitch (to 4") some George Aldrich 9" wood props..
Bill <><