Puppeteer

Author Topic: McDonald Imperial Super Diesel Crude Oil Engine  (Read 1912 times)

oldgoat

  • Full Member
  • ***
  • Posts: 145
    • View Profile
Re: McDonald Imperial Super Diesel Crude Oil Engine
« Reply #45 on: July 27, 2020, 06:02:07 AM »
You will only get blowback if the needle and seat are leaky or the injector adjustment is incorrect.

cobbadog

  • Sr. Member
  • ****
  • Posts: 402
    • View Profile
Re: McDonald Imperial Super Diesel Crude Oil Engine
« Reply #46 on: July 27, 2020, 12:28:59 PM »
YEs that is right but it can happen so I built this bomb proof model
Coopernook - the centre of our Universe.

cobbadog

  • Sr. Member
  • ****
  • Posts: 402
    • View Profile
Re: McDonald Imperial Super Diesel Crude Oil Engine
« Reply #47 on: July 27, 2020, 12:33:11 PM »
Hi Mike,
As oldgoat mentioned the cause of the blow back is a poorly seating needle. Fuel is gravity fed to the Hyvid Brons injector and pressure is a very simple plunger inside that has a spring inside to help seal the needle. If blow back happens it all ends up back at the tank which for my tank the worse that can happen is the lid will lift off.
Coopernook - the centre of our Universe.

cobbadog

  • Sr. Member
  • ****
  • Posts: 402
    • View Profile
Re: McDonald Imperial Super Diesel Crude Oil Engine
« Reply #48 on: August 06, 2020, 12:43:08 PM »
Today I got some play time and found an issue. Again I wiped out the bore and sprayed some Lanox inside and fitted the piston with no rings. I have a cylinder that is narrow in the middle of the stroke. Fromt between 45mm down from the top to 125mm down the piston sticks. But, if I rotate the piston 90' it does not. This may indicate an oval piston so I now have the piston in the chuck of the lathe and checking it with the dial indicator to see what is at fault.
I think that all that rust around the cylinder has swollen up and distorted the bore.
Coopernook - the centre of our Universe.

glort

  • Hero Member
  • *****
  • Posts: 3405
    • View Profile
Re: McDonald Imperial Super Diesel Crude Oil Engine
« Reply #49 on: August 07, 2020, 04:41:25 AM »

I thought pistons were SUPPOSED to be oval??

cobbadog

  • Sr. Member
  • ****
  • Posts: 402
    • View Profile
Re: McDonald Imperial Super Diesel Crude Oil Engine
« Reply #50 on: August 07, 2020, 12:04:04 PM »
Not this one, fairly certain it is the bore that is distorted.
Coopernook - the centre of our Universe.