M18 Oil Pressure issue

[J-Mech]

Originally Posted by ol'George

The vertical jugs have an oil drain back hole drilled in the spigot, or mounting base if you prefer.
Since the horizontal block is not drilled for a matching hole, there will be no problem.
But if horizontal jugs are used on a vertical engine,(no hole)
the drain back holes will need be drilled in the spigot, or the oil will pool in the valve spring chamber causing too much lube oil remaining in there.

Good info George, but if I understand him correctly..... he pulled the used bearings out of the MV14 and put them into the M18. Swears the crank was good.

I love the H motors.... but I hate to fix them. Such a poor design.

[ol'George]

Originally Posted by J-Mech

Good info George, but if I understand him correctly..... he pulled the used bearings out of the MV14 and put them into the M18. Swears the crank was good.

I love the H motors.... but I hate to fix them. Such a poor design.

If his main bearings were worn, and the inner and outer rotor of the oil pump
was found with a lot of clearance,
I can see the low pressure condition.
Those cranks are hardened, been my experience they are pretty tough.
The main bearings are costly, but I think they are still available.
I'm optimistic, if he assembled it properly.

[J-Mech]

Never seen a crank that wasn't hardened. Never seen a crank so loose you could wiggle it in the bearings that was still good. By the time they get that loose.... everything is done. If it ran low on oil that much, it had to hurt the rods. I give it less than 50 hours. I would never go to the trouble of tearing down a split block and putting it back together with used parts. Talk about a waste of time.

[mobermiller]

I'd like to say something J-Mech. I have no reason to lie about anything I post here. You can believe me or not. I am a disabled person who lives life from a wheelchair. I spent my last dime on getting this super and saved to buy one for quite a while. I not a dumb-ass as you seem to be implying. I have to be frugal with my money. I broke every rule of engine rebuilding by using used bearings. I didn't have $140 for a pair of new bearings but I had these from a low time vertical Magnum engine I had robbed the jugs off of. I must have done something right to get the oil pressure back up to 25 psi at hot idle from almost zero.

Before I opened the case I checked the cam to see if I could wobble it though the opening under the closure plate. It was tight. I opened the case and checked the crank. It did not have scratch one. PERIOD! I removed the old worn sleeve bearings and put on the used bearings. Hmmm! No play in them. Checked rods. No play. Reassembled engine. Ran it 3 hours today. 47 to go.

I can't explain it. From the side play I had on these bearings you would think the engine was shot and I expected it to be shot. Both bearings were extremely worn. There was no indication that these bearing had ever been starved for oil. They were just worn out! I can't explain it.

I will take a picture of the hour gauge tomorrow. I doubt I'll be able to put 50 hours on it the remainder of this season, but like I said before, 3 down 47 to go.

[J-Mech]

I've seen so many cranks that "didn't have a scratch" on them that were wore beyond spec I can't count. Unless an engine had a catastrophic failure, that's usually how they wear. Evenly. I'm sure a set of used bearings and oil pump did tighten it up. No doubt in my mind. You say you couldn't "feel" any play in the rods. Great. You understand that the rod should only have like .003" clearance right? (Likely more like .002", but I'm not going to go look up the spec.) Even if they had twice that you wouldn't be able to "feel" it. Unless you used a mic on the main journals of the crank, took the rods off and mic'd the journals, inspected the rod bearing area, then plasti-gauged them to see what the clearance was, you have no clue on earth how much wear there was on any of those parts. So.... after all the time you spent doing that work, let's say it runs 40 hours and let's go. Now what? Now you are time and money behind when you could have checked those parts while you had it apart, saved your pennies and fixed it right. Then you might get 500 hours out of it instead of 50. Even if you do get more than 50, you are only running on luck and hope. Neither of which is a good plan. How do I know you didn't just mistake the end play as side play? Did you put a dial indicator on the flywheel or PTO and measure it??) Unless you did the checks that I listed, you are only guessing. Unless you have a whole lot of mechanical experience, and even if you do, guessing is never accurate. Grabbing internal parts like rods and jerking them around to see if they have play is not "checking" them. Looking at parts and running your fingers across them is not a good indicator of wear. I don't want anyone reading this for the first time and wanting to do a rebuild on an engine thinking this is how you do it.... that's why I make these posts.
Good luck with your engine. That's really all I can say.

[mobermiller]

I agree with everything you said. I want to thank you for all your help and the help from others in this forum. Thank You!

[farmall fred]

I just wanted to wish you good luck on your low cost repair job. When the money is low and you have the time to do the labor there is nothing wrong with a patch job with used parts. I hope it runs for a good long time for you. Back when I was first married and money was tight I was able to buy very cheap three KT-17 warranty engines from a local JD dealer who replaced them when they threw a rod. I was working at a parts store with a machine shop and the machinist and I straightened the best crank, he turned it down just enough to get the rod journals round and then took the two best rods and cut the caps and honed the bores to fit the crank. We honed the cylinders, used the best two pistons and main bearings from the three engines ground the valves and seats surfaced the heads and re rung it. The only new parts I had to buy were two sets of rings and a gasket set. This patched up KT-17 ran for many years mowing and when I traded off the 109 I had installed it in I traded engines with my brother who had a tired Kt-17 in his Simplicity and he used it for another six years before it finally gave up. So you never know your engine may last 50 hrs or could go 500. Good luck.