I looked at the main bearings before I sent the rods out. They look good. About a 4 inch journal.
Attachments
-
75.7 KB Views: 466
-
85 KB Views: 458
Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
madsam said:I do have 2 problems with the design of this engine.
1. There is no air filter. The intake runs over to the exhaust for warm air then out the top holes. I know it is supposed to be run when it is snowing, but I would feel better if it had even a simple cloth filter. I cant change it to much without re adjusting carbs. (I did that on an old Honda motorcycle. Put a better filter and had to adjust all the carbs again. )
2. There is no oil filter. There is just a strainer with 1/32 inch holes. Especially with this engine meltdown, I think it needs a filter.. Don't know what that means.
quote]
This is the same situation as the 22hp 4 cyl in my Model T. Really its perfectly fine in this setup. You have to think about the air and what it does when it gets heated by the exhaust manifild. Once it gets hot it expands and thins out, rising and whatever is in it drops out. This is how it was explained to me and theoretically that is how its supposed to work. Dirty air as a contributor to engine wear was not overlooked back in those days, this was supposed to be the way to go. My little car has an accessory heater exhaust manifold on it and the standard air tube does not hook into my exhaust manifold like regular T's but instead gets ducted in from another tube which I have eliminated. You should not have to replace or even adjust much on your carb to compensate for a little restriction. If it does make some little difference to your idle then back the fuel screw out a little more till it catches up. I assume this is a governor controlled engine and if it is working properly it should compensate. For an air cleaner, if you can graft an old tractor oil bath cleaner on there then that is the numero uno way to go. If not then you can make one with some pipe, steel wool, and a jar. You can also make a cotton gauze one by just forming a basket out of brass screening (fine screen like screen door screen) and wrapping it with gauze.
For the oil filter, if this engine is a splash lube setup then all is cool and its not really a problem AS LONG AS YOU DO NOT USE A DETERGERENT OIL Repeat, do not use an oil with a detergerent in these engines. If you do the sludge will clog up your oil ports.
If the engine has a pump and is force lubricated (I just saw the ports in the crank so I assume it is) then you need to tie into one of the oil galleys and find out how much pressure is being delivered to the bearings. I would wager it is low like maybe 10 psi. In such a case just clean the screen when you do an oil change.
There is a way to add a filteration system but it is slow and must be bypassed. The tolerances in these old engines are not tight and do not require to be pressure fed absolutely clean oil. Best thing to do is check around on the Model T and A forums and look at how folks are doing this with their outside oil lines. Basically the oik gets splashed up to the top of the hogs head by the flywheel and the oil is fed via outside line to the front main bearing where the flow of lubricating oil delivered by the inside oil line is at its least. We tap into this line, add a spin on oil filter and then redirect the clean oil to the pan. The outside oil line functions as normal but part of the flow is fed to the spin on filter and that oil is gravity filtered to the pan.
The biggest killer on your engine is the cast iron pistons. That is where these old engines suffer. With T's and A's we chunk the original pistons and replace them with aluminum pistons which all parts suppliers to this hobby carry. This gives the engine a little more snap by lightening it up and gets the load off the bearings. You never have to take the bearings up again after that and it makes it just as efficient as a modern engine.