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| | | | Joined: Jan 2013 Posts: 2,232 Moderator: Interiors, Texas Bolters, Name that Part | | Moderator: Interiors, Texas Bolters, Name that Part Joined: Jan 2013 Posts: 2,232 | Gents,
I just had a guy tell me that when a gasoline engine diesels, there is a good chance that it spins backwards.
He claims that it hurts the engine by not getting oil.
Questions:
1. Is this a common issue? My 261 and 216 diesel for a couple seconds and I’ve never had an issue.
2. Are there certain engines more prone to this issue?
3. How does 1-2 seconds of minimal to no oil hurt an engine that thrives runs on lower pressures when idling (216, 235, 261). Mine 235 and 261 run at 30 plus PSI until warm and then drop low when idling.
Thanks guys, I just can’t wrap my brain around this. Maybe I’m overthinking it?!?!
Chris | | | | | Joined: Feb 2004 Posts: 29,746 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,746 | Dieseling is caused by excessively lean idle mixture and/or too high idle speed. Richen it up and slow it down, and the problem disappears. Or- - - -leave the transmission in high gear and let the clutch out as you turn the ignition off. Dieseling is impossible if you do that. Is your "expert" available to talk to my garden? If so, I'll save a fortune on fertilizer
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Jan 2022 Posts: 2,436 'Bolter | | 'Bolter Joined: Jan 2022 Posts: 2,436 | Old time 2 cycle lawn mower engines can be run backwards, but I doubt any 4 cycle engine could. How would it get fuel in through the exhaust valve?
Last edited by Bill Hanlon; 11/14/2024 11:01 PM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
| | | | | Joined: Feb 2016 Posts: 1,982 'Bolter | | 'Bolter Joined: Feb 2016 Posts: 1,982 | I had a V8 that sounded like a diesel every time I started it, it ran great but a little noisy, it never ran-on when I shut it down which is kinda' strange since it was a diesel!
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
| | | | | Joined: Jan 2013 Posts: 2,232 Moderator: Interiors, Texas Bolters, Name that Part | | Moderator: Interiors, Texas Bolters, Name that Part Joined: Jan 2013 Posts: 2,232 | Jerry,
The dieseling doesn’t bother me a bit. I was just curious since the hair on the back of my neck was saying to put my hip waders on because it was getting deep!
Chris | | | | | Joined: Feb 2004 Posts: 29,746 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,746 | The "running backwards" idea is mostly "bovine scatology". The engine might kick back half a turn or so if a cylinder fires before the piston gets to the top of its stroke, but it's so simple to avoid the problem with the right idle speed that there's no reason to put up with it. If it won't idle around 450-500 RPM, there are other problems that need to be addressed.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
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