Search results

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
  1. M

    Just moved to Washington

    I just moved to the Carnation / Redmond area and i was wondering if anyone in the area might now of a job opening in the area. I thought id ask don't know if its a faux pas to ask here.
  2. M

    Nitro V8

    thanks you guys. im in the process of applying and interviewing for jobs. after everything is settled down i have my eye on getting an sieg x3 mill. then hopefully work on getting the parts to cnc it. and since most of the stuff i work on is small i was contemplating building a jig to allow me...
  3. M

    Nitro V8

    unfortunately i do not know when i will be able to work on it again. i do not own my own my own machines. and im finished with school.
  4. M

    Nitro V8

    sorry for no updates between learning matercam and sharing machine time with other students things provided slower then expected. i was so caught up in trying to get parts done i didn't take picks. now that the semester is over i took some of what i got done the engine block was made using the...
  5. M

    Nitro V8

    school starts the 27th. I've got to batten down and double check all my parts. it's going slow considering i just started quitting smoking. my brains all fuzzy lol. every time i try concentrating i unconsciously get up and head out for a smoke. It's hell but it needs doing. lol
  6. M

    Nitro V8

    i believe the effective volume of the crank case will stay the same. while one piston is going up another is going down. the crank case pressure will only get as high as boost pressure and cylinder pressure will always be greater then or equal to boost pressure. therefor there should not be much...
  7. M

    Nitro V8

    port timing is: intake 112.02-247.98 duration 135.96 exhaust 81.79-180 duration 98.21 pay attention to the left cylinder. the right valve is off timing. http://youtu.be/_o1erbmHEIQ better view of intake port
  8. M

    Nitro V8

    i have an intake port. its at the bottom of the stroke. its .125 in diameter routed directly from the intake valley. a pressurized crank case is a side effect. when the piston is at tdc, the intake port is uncovered by the piston allowing air/fuel into the crank case. i cannot increase the...
  9. M

    Nitro V8

    re: rotary valves no i cannot use the valve for intake. first having an exhaust port means that the port is open equal time on both the down and up stroke. I don't want this. I want the exhaust to open before the intake to relieve pressure. then open for a period of time with the intake to allow...
  10. M

    Nitro V8

    can anyone tell me the carb barrel port size on a .12ci/2cc nitro engine? given the effective displacement ~.137ci and the fact that i have two intake ports open at a time I think 2 carbs of roughly .12 size would be a good place to start for carb sizing. i got the effective displacement by...
  11. M

    Nitro V8

    the rotary valve is for exhaust. air/fuel mix goes through the supercharger into the valley. the valley has ports leading to cylinder. as the piston moves down the cylinder the exhaust valve starts to open. at roughly .125in from bdc the exhaust valve is completely open and the intake port is...
  12. M

    Nitro V8

    ok then I increased my deck height and increased my con rod length. as long as you think 0-80 shcs will hold up i can use a solid crank. now to contemplate this new can-o-worms. since its going to be a softer metal what bearing material should i use?
  13. M

    Nitro V8

    Skyline1 C.I. bearing do they work at low speed (idle) with no forced oil. trumpy81 I don't need to seal the different cylinders because I'm using a supercharger. That is also why I'm using the rotary valve, so i can build boost. also i cant use the bearing crank cause it would get into my...
  14. M

    Nitro V8

    My engine will have two carbs and Steve Huck has graciously allowed me to use his carb design from the Demon V8. Now the Question is carb sizing and whether or not to offset them in a way so the second carb acts like a secondary. would that allow me to more easily control mid range air/fuel...
  15. M

    Nitro V8

    piston and connecting rod i am using piston rings and unless 0-80 screws will hold the connecting rod end caps on i see no way to make two piece connecting rods that will fit in my block. i modeled using 2-56 screws but the connecting rod would hit the bock and opposite side piston...
  16. M

    Nitro V8

    wow that's a really cool crank design. with how compact this engine design is i can't impalement anything like that but that's definitely something to store away for later pondering.
  17. M

    Nitro V8

    its a small collage. our edm is cobbled together just big enough for tap removal it would take a day per hole. the broach i have works basically works by pushing a tapered square file through a pre drilled hole hopefully this wont distort the web to much as for a one piece crank i didn't leave...
  18. M

    Nitro V8

    cast iron bearings... interesting. that would solve a worry i had about using sintered bronze and the the worry about my rotary valves. id like more info on how you prepared these bearings please. my multi piece crank was for ease of making but i do worry about its strength. if i one piece it...
  19. M

    Nitro V8

    ok so why i came to my valve design. with some trial and error, math, and a lot of letting it float around in the back of my head i came up with a timing equation. circumference of rotary valve / 360 * degrees you want the valve open / turning ratio (2 for half crank speed) / 2 = diameter of...
  20. M

    Nitro V8

    valves the valves are .25in drill rod drilled down the center .125. they rotate at crank speed. the exhaust holes (in and out) are offset for timing and to hopefully limit blow by. any advise of rotary valves would be appreciated. tolerances and friction limiting. i'm kinda hoping ether...
Back
Top