zuhnc
Member
- Location
- Macks Creek, MO
I recently purchased an oil filter conversion kit - cartridge type as originally installed to a spin-on type. Ran it for a while with 10W30 dino oil, as I had recently also re-ringed the engine, seal replacement, etc. Oil pressure hot at 1850 RPM was about 15 PSI, and hot idle was down near zero. After running this oil for about 20 hours, I wanted to change it and install the 20W50 synthetic I normally use in this engine. Oil pressure before the engine work, with the 20W50, was 25 PSI cold or hot, idle or operating speed.
I changed the oil and filter. On startup, oil cold, pressure was 20 PSI. I found this odd, especially with the thicker weight oil and being cold. The only change from before engine work to after was the conversion kit. I decided to investigate. The oil path is through the original canister filter, through the tiny hole in the center of the canister filter tube, and thence to the governor. I measured that hole and found it to be 0.060" in diameter. I removed the conversion kit, and removed the center adapter the filter attaches to. That adapter does have an orifice in it, but that orifice was 0.090" in diameter, 50% larger than the original canister filter hole. That translates into 4 times the area, and will allow quite a bit more oil through, especially when hot.
I drilled that orifice out so a piece of 3/16" brass rod could be pressed it it, and then drilled that brass rod for a 0.065" diameter orifice (closest drill bit to 0.060" I had). I reassembled all the components and reinstalled the adapter to the engine. Now I have 25 PSI oil pressure, cold at idle, and 45 PSI pressure at 1850 RPM.
I have yet to operate the tractor, under a load (brush cutter), to get everything hot enough and up to temperature. A lot of rain here, and too wet to mow.
So, low oil pressure issues might be related to that orifice in the original oil filter canister, if the engine is otherwise in good condition. Or, if a conversion from canister-type to spin-on has been done, the orifice in the conversion adapter might be incorrect.
I will further update this post when the ground becomes dry enough to mow some pastures. zuhnc
I changed the oil and filter. On startup, oil cold, pressure was 20 PSI. I found this odd, especially with the thicker weight oil and being cold. The only change from before engine work to after was the conversion kit. I decided to investigate. The oil path is through the original canister filter, through the tiny hole in the center of the canister filter tube, and thence to the governor. I measured that hole and found it to be 0.060" in diameter. I removed the conversion kit, and removed the center adapter the filter attaches to. That adapter does have an orifice in it, but that orifice was 0.090" in diameter, 50% larger than the original canister filter hole. That translates into 4 times the area, and will allow quite a bit more oil through, especially when hot.
I drilled that orifice out so a piece of 3/16" brass rod could be pressed it it, and then drilled that brass rod for a 0.065" diameter orifice (closest drill bit to 0.060" I had). I reassembled all the components and reinstalled the adapter to the engine. Now I have 25 PSI oil pressure, cold at idle, and 45 PSI pressure at 1850 RPM.
I have yet to operate the tractor, under a load (brush cutter), to get everything hot enough and up to temperature. A lot of rain here, and too wet to mow.
So, low oil pressure issues might be related to that orifice in the original oil filter canister, if the engine is otherwise in good condition. Or, if a conversion from canister-type to spin-on has been done, the orifice in the conversion adapter might be incorrect.
I will further update this post when the ground becomes dry enough to mow some pastures. zuhnc