Thought this a bit weird today. Same truck, 87 F250 6.9 4x4, same fuel, same weather as last drive to work. I changed the oil draining out the Delvac dino oil 15/40 and refilling with some older stock Detroit branded CI 15/40 that's said to be made with "Delvac technology" Headed home this afternoon up the same miles long grade that I always have pulled with it floored doing 55, and today she dropped below 45 mph. Sounds iffy but fresh unbeaten down oil has always felt different in my bikes and vehicles, but a 10+ mph loss on a fire breathing 6.9?
Oil drag?
- Thread starter Halfpint
- Start date
icanfixall
Official GMM hand model
Not sure of an answer to what you described here. Our engines do not rev high enough for oil to become a drag and I have never seen a dry sump or crank scrappers either. My guess is possibly temp differences caused what you posted about.
Macrobb
Full Access Member
If you are going up this grade unloaded, floored, at 55? I'd check that you are getting enough fuel at the right time.
I've had one truck that seems to have a partially clogged fuel pickup or something of that nature; it feels fine, but just doesn't go very well when accelerating up to 60 or 70.
Swapped a known-good, fully-turned-up-IP onto it, and floored I'm getting no smoke at all... and I should. What the IP came off of had a turbo, and you could easily make it smoke.
If you /are/ getting smoke while floored, is it black or white? Timing /massively/ affects power available, with a turbo or not. Too retarded and you may well smoke white. Too advanced, and it'll be black and clatter a lot.
My rule of thumb on timing is that it should clatter a bit when cold, quiet down when warm, and when accelerating at WOT, you should hear just the tinyest bit of clatter. No clatter at all and you'll probably see white smoke as well.
I've had one truck that seems to have a partially clogged fuel pickup or something of that nature; it feels fine, but just doesn't go very well when accelerating up to 60 or 70.
Swapped a known-good, fully-turned-up-IP onto it, and floored I'm getting no smoke at all... and I should. What the IP came off of had a turbo, and you could easily make it smoke.
If you /are/ getting smoke while floored, is it black or white? Timing /massively/ affects power available, with a turbo or not. Too retarded and you may well smoke white. Too advanced, and it'll be black and clatter a lot.
My rule of thumb on timing is that it should clatter a bit when cold, quiet down when warm, and when accelerating at WOT, you should hear just the tinyest bit of clatter. No clatter at all and you'll probably see white smoke as well.
First off Im not sure what to expect from the truck. Ive had 3 dodges and a old 240D benz in the way of diesels. In 39 years of driving some 250 vehicles :0. Smoke wise a puff of white on start up and very little black with it pegged. I switch around fuel stations and use 2 stroke and/or Diesel kleen most every fill up. The only thing I really notice is a bit better mileage with 2 stroke. The grade is my HP and cooling system testing grounds so to say. Ive had gassers that struggle to keep 55 or 60 mph. Doing some reading on pump timing and everything sounds and looks normal IMO. The truck only has about 55K miles on it now and its 100% factory original.
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