It's coming along good. I got the 1.25 inch shaft turned town about 0.88'' (originally it was 7/8'') and press fit it into the cutter head. For the cutter drive pulley I found a solid cast iron 200mm or 8inch 3belt cast iron 2012 taper lock pulley someone wanted gone shipped for $22. A 1.25 inch 2012 taper lock is like $30. 2012 and 1610 are my preferred taper lock sizes. For the engine I'll do a 7 inch pulley. That will make the cutter speed about 3,100rpm.
I turned down and press fit a 1.25 inch 4130 shaft into the old cutter head and welded it on. Did tig then stick weld over top of it. Yeah its not coming off. It can chip dry firewood now barely slowing down. The cutter is driven about 80% of engine speed. It can easily have 2 people feeding it. Twigs and leaves into the shredder and small sticks like I normally wood chip into the chipper. With the 6.5hp engine it was chip or shred, not both. I think I'll mod the single cutter head to make it a 2 cutter head and put a predator 459cc on there. The old Honda gx390 really isn't lacking much if any power. I bought the motor moint plate that will fit big block 1cyl and most V-twins. I need to put a guard on it.
The old gx390 is burning a lot of oil. So I retired it, for now and replaced it with a predator 459cc. I installed the 6,000 to 8,000 feet above sea level jet (I'm at 4,000ft). The stock/sea level jet is a size 100. The 3,000 to 6,000ft jet is a 97 and the 6 to 8 thousand ft high jet is a 95. With the 95 it wants to sputter and die at first, till it warms up a bit maybe 10 seconds of half choke and another 20 seconds of at least fast idle (using ethanol free gas). I cranked the engine over with my DC amp clamp, it was reading 55 amps.
I got the 75 inch long straight pipe on the wood chipper, it actually sounds good. Me and another person can feed it no problem, one of us wood chipping and the other throwing twigs and weeds in the shredder. It just doesn't care. Made a big pile of chips yesterday. Running the "6,000 to 8,000ft elevation jet" at 4,000ft, with ethanol free gas and the straight pipe seems to do the trick. The spark plug is still white after burning 3 gallons of gas. The engine sputters on start up a little bit more with the straight pipe but hot starts fine. I jammed a big ass tree in it and could have stalled it if I didn't let up, other than that it never lacked power. It runs for a long time on 1 gallon of gas, definitely longer than the gx390. I'm pretty sure I'm getting more wood chips out of a gallon of gas running that gallon of gas in the 459cc than when it had the 208cc engine. A gallon of gas in the 208cc would make a nice pile, a gallon of gas with the 459cc makes a small hill.
New mod, I put a 8 to 9 degree timing advance key in my predator 459cc. Next mods are to replace the thicc 0.045 head gasket with a 0.007 inch thick one, that will bump the compression about a half number. And add a bypass oil filter. Just a regular 20 to 30 micron oil filter. It should at least double to quadruple oil life and at least double engine life.
I pulled an oil sample, no gas smell, appears to have some metal dust in the oil. Going to do before and after oil samples for the filter install.
I got the oil filter installed. I'm doing a syentyfic test. I ran it for 3 to 4 hours with no filter, pulled a sample and now I'm going to run it 3 or 4 more hours with the filter pull another sample and get it tested. Once shtf happens I won't be able to buy another engine for $500.
Centrifuge will work nicely on that oil as it spins out particles but you must be aware it possibly can spin out additives in the long run.
It's just a regular oil filter that bypasses some of the oil from the oil pump through a filter and back to one of the drain plug holes.
I sent the oil sample. off to be tested and got the results back, 3hrs of total run time and 3hrs total on the oil the oil has 30ppm of iron and 13ppm of aluminum, with out the filter. Which is more than I have ever seen on an oil test. The lab says to run it, like that for 10 to 15 more hours... Well it's got the filter on it now. There's already been a substantial reduction of metal flakes in the oil. Just running it for 20 minutes at idle with the oil bypass going wide open. Going wide open the oil was being filtered about 4 times per minute. I added a valve to the return side of the filter to slow the flow and keep the pressure up. I start it, open it up and allow 3 to 5psi of oil pressure to bleed off to the filter. With the oil restrictor valve bleeding off that 3 to 5 psi the oil is being filtered about once a minute. The manual says to change the oil every 20hours. The idea behind adding the filter is to increase oil change time from 20hrs to 100 to 200hrs and have the engine last a lot longer.
I added a oil temperature gauge to the oil filter, it's only hitting 160f so don't need an oil cooler. The way wood chipper engines run they're usually not running 3,800rpm at wide open throttle. More like 3,000-2,500rpm with plenty of unloaded and light load time. I'm up to 7hrs total on this engine.
It looks like adding an oil filter can increase engine life up to 8x according to ACdelco. How to Choose the Right Oil Filter for Your Car Searching around on the internet it looks like cheap consumer grade lawn mowers with out an oil filter last 400 to 800hrs and commercial grade with an oil filter and good air cleaner last 5,000 to 7,000hrs depending on how much tapping noises and oil burning you're willing to tolerate.
The best way to light up woodchips is toss about 2oz of kerosene/diesel mix on them and light with an open flame. It burns fast without much smoke.
Running an engine with a wire mesh oil filter which is pretty much a trash screen, closer to no filter at all vs a boring very typical 25 micron paper oil filter. When the engine had the wire mesh rock catcher with dirty oil it lost 10hp after running for 1 hour. With the paper filter there was no noticable loss in power.
