Search results

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

  1. Engine maker

    O Ring for piston rings

    I don't know about short run times, my engines at the shows run between 8 and 9 hours straight, only stopping to refuel, and then start right up again. Although there is a lot of coasting going on. JimG
  2. Engine maker

    O Ring for piston rings

    The only time I saw the Buma "O" ring swell was when the person that was running it was running it on gasoline. Coleman fuel doesn't seem to attack the Buna. Jim G
  3. Engine maker

    O Ring for piston rings

    I've also done some unofficial test on the different "O" ring types Vitron, Silicon and Buna. I used the same hit and miss engine for all the tests. Put new "O" ring on each time and let the engine run for 20 minutes to warm up each ring. This is what I found Silicon - engine ran the hottest...
  4. Engine maker

    O Ring for piston rings

    I've built a lot of engines with "O" rings for piston rings. Any where from 5/8" to over 2" and use the same proportions. On a 3/32"(.093") "O" ring I make the groove .105" wide and .110" deep. For a 2" "O" ring I use .210" wide and .220" deep. I also reduce the piston diameter in front of the...
  5. Engine maker

    Sight glass for fuel tanks etc

    If you need Glass for fuel tanks I always use this site. Been using it since 2009. They have Flat Mineral Glass watch crystals in many sizes. This is just one page. You may want to bookmark this page as it's quite a large site and easy to get lost. They have thicknesses from 1mm to 3mm and...
  6. Engine maker

    Viton o-ring Headgasket

    I do it all the time but prefer to use either 3/32 or 1/8 inch"O" rings. Works great. I even have one engine that has no recess for the "O" ring, just put it on instead of a gasket. But if you don't have a groove and compression is high it may blow out after a while. If you look at the build...
  7. Engine maker

    Jerry Howells hit and miss

    I get mine at the local hardware store. Off the shelf "O" rings work just fine. I know some people say you need to use Vitron, but I've never seen a difference. I've got several engines from 3/4" bore up to 2" bore and all run just fine on standard "Buna" "O" rings from the hardware store. I...
  8. Engine maker

    New Member and need info

    Don't go jumping and assuming it's the "O" ring right off the bat. These engines often have a "Dirt" problem with swarf in the intake and exhaust that get stuck in the valves. The few I've fixed for people all had chips from machining under the valves. Try blowing out the intake and exhaust and...
  9. Engine maker

    Farm Boy running

    As for the cam roller, I've used a small ball bearing from the hobby shop or something that I've junked. The hole will be bigger but that fine, just turn a small bushing that looks like a"top hat". Then counter bore the bushing so that the cap head screw (I use allens) is inside the bearing and...
  10. Engine maker

    Cylinder head gasket

    The Farm Boy uses an o-ring as a cylinder head seal, works just fine. It's 1 3/16" od and fits in the groove that's made between the 1.200" od of the cylinder and the 1.340" id of the cylinder end of the wate rhopper. It just sets in the groove. A 1/16" cross section works but if your sizes...
  11. Engine maker

    Mideast Model Engineering Show 2021

    I'll be there. It will be good to see everyone again! Jim G
  12. Engine maker

    Farm Boy running

    Nice work, I built SN# 003and the double size one SN3003-X2. Denatured alcohol or Coleman Lantern fuel (white gas) both work fine, but with alcohol you have to lube after running so it won't get surface rust. As an added point, with Coleman you can run it in the house with almost no odor. Easy...
  13. Engine maker

    Farm Boy Milestones

    I built SN# 003 and SN# 003-x2 (twice as big). On the weights they are correct. Since it near impossible to solder the pins into the barrel distance with accuracy, it was made to solder the pins in then and then screw the brass balls down till you get the size you need. Then either solder or...
  14. Engine maker

    How to Scale Up An Engine

    I built Bob Shores Little Angel double sized. The original Little Angel is about the same size as the Kerzel. I just doubled all the sizes. There were no problems and it runs great. I actually built the double sized one first! Jim G
  15. Engine maker

    FarmBoy SN# 003-x2

    Finally got FarmBoy SN 003-x2 on its sled. Enjoy the picture of SN 003 and SN 003-x2.
  16. Engine maker

    J.E.H. Farmboy

    Sorry, can't type for **&*(. Meant to cay CAM. If you listen when the engine fires you can hear the cam hitting the roller on the exhaust rod. Count the clicks till it fires again. Since the cam turns at 1/2 the crank speed multiply by 2 to get revolutions coasting. Just cause ti turns free it...
  17. Engine maker

    J.E.H. Farmboy

    I built SN# 003 in 2009 and have never put water in it and it runs 9+ hours straight, no stopping at the engine shows. I've never seen it any hotter than 96 degrees ( outside air temp). You may not be coasting between firings long enough. Listen to the cam "clicking" between firings and...
  18. Engine maker

    hauling a small mill

    You can save yourself a lot of time, hassle and worry by calling a Rigger. They picked up my new/used 14 x 40 lathe out of a shop, moved it 40 miles, and moved it through my garage, a man door, into my shop, and put it exactly where I wanted it. All for $300. Didn't get my hands dirty and no...
  19. Engine maker

    O-ring for piston ring

    I have many engines running with just off the shelf black Bunan "O" rings. From 3/4 inch up to a 2 " bore FarmBoy I just built. No problem with the "O" rings. Last forever. Most people try to make it too tight and it binds and doesn't float. I use the sizing that Jerry Howell uses on his regular...
  20. Engine maker

    TIM 6 ignition

    I just pasted those numbers into Ebay and got 600+ offers. FYI for anyone that cares, years ago Jerry Howell also sold a TIM-12 which was a 12 volt ignition. I think I still have one or two unbuilt kits laying around somewhere. Jim G