RC150 Nitro Engine Help

[morrisey0]

Make sure the sleeve and piston go back in the proper orientation

I can all but guarantee it will all go in backwards!

[morrisey0]

And down to the last piece; the inner bearing. Can't grab it on the outside, can't grab it on the inside. Heat?

[GoMachV]

I use a heat gun, and slam it on a piece of wood a couple times. They rarely come out easily

[morrisey0]

I use a heat gun, and slam it on a piece of wood a couple times. They rarely come out easily

Worked like a champ!

So, I am sitting down and looking at bearings. With this being a static engine, I could stick anything in there, but again, I would like to do it somewhat right. Apparently there is a such thing as engine bearings for nitros. Is it common practice to only stick to these bearings for these engines? Or do people deviate from this without issue? My bearings are non-shielded, should I stick with this, or has bearing technology in the past 40+ years made it so that there are shielded bearings that will work? I am seeing bearings labeled as engine bearings that are both shielded and non. Avid doesn't carry my inner / back bearing, and I can find it elsewhere as an "engine bearing," but I am also seeing them at $40+, which I would like to avoid.

[GoMachV]

the front bearing will usually be shielded, only the side up against the flywheel. The rest should be open, as the oil in the fuel will lubricate them. Back when these engines were made, we didnt have cheap Chinese bearings, so every bearing was an engine bearing. These days if you did plan to run it id buy a proper quality bearing made for an engine. For a light run or just a start to verify it runs you could use cheap ones. If you buy shileded bearings you can always just pop the seals out for all but the outer front.

Also, id try to clean those stock bearings up if they look decent. The quality is probably better than what you will get in a cheap modern bearing anyway. I cleaned up a set of NMB that were gritty not long ago and they spin like mad now and are just amazing compared to the china stuff.

[morrisey0]

I cleaned up the bearings as well as I could with the ultrasonic, but both of them had a little crunchy spot to them. The inner one also had a bit too much play. I found that Boca had a set specific to the engine, so I didn't have to buy extras or anything, and those are on the way.

I then found out that there is a slightly different version of this engine, one modified by K&B for cars. On this one, they rotated the head 90* so the fins are in the correct orientation, and this would be a different bolt pattern on the block. This engine doesn't have a flat piston, so I am assuming the piston is also different, maybe the piston and head. I know where one of these is NIB, and at a great price, but it is on a plane forum, and I am having issues with making a transaction work as a newbie on the forum. There is also a locked up one on ebay that I am watching.

Edit: I just realized that this is the version shown in the early K&B ad I posted at the beginning. I didn't pay attention the head rotation. That would make sense because they are advertising a car exhaust.

[morrisey0]

So, I ended up making the deal on the dual engine combo. There is a guy that I trade with often, and he is a plane guy, and he ended up being a member of the site where they were being sold, so going through him, money is off and these should be on their way tomorrow. I ended up with both of these shipped for about the low end of purchase price of what a new one shows up on ebay for. Super excited about this!!

I still plan to pseudo-build the one that this thread has been about, and I think the final condition of the car will dictate which motor it gets. If the car comes out close to mint, it will get the new engine. If it comes out looking like a nicely cleaned up old car, then it will get a nicely cleaned up old engine.



Same engine, just the head is rotated 90*, which isn't as easy as rotating the head 90*.

[morrisey0]

I scored the locked up one, with pipe, for $10. I took it apart, and I had overcomplicated the differences between the normal one and car one in my head. All they did was change the head bolt pattern and the cut out in it for the piston. Not sure why I thought it would have been more complicated than that. Oh well, I broke it down just like the last one, and dropped her in the carb cleaner. Give it a few hours and see if the magic works.

[morrisey0]

Quick question ......... what should I use for an assembly lube, mainly being something I would already have sitting around? I have 1:1 engine and trans assembly lubes, and all the other garage greases and oils.

[GoMachV]

im probably going to get called out on this but I have always used a little marvel mystery oil. Back in the day I heard old timers would add it to their fuel, so I considered it safe. Is it? Its a mystery

[morrisey0]

MMO it is!