Oem truniun bearing vs trunion bushing
#23
TECH Senior Member
#24
TECH Junkie
iTrader: (9)
I hear of this, but I have yet to see it and NO ONE runs their cars harder than I do. I've spun my 6.2L over 9 grand a few times, and over 8000 countless times, stock rockers, no issue, 0.600" lift. I have installed cams as big as 0.630 lift but now mostly install cams in the 0..560" lift range. A few ponies only available past 6500 RPM dont interest me, and nor should they anyone else unless you are class racing? Add cubes or boost. Leave the donkey dink cams to the ones who tear apart engines every weekend
#25
TECH Enthusiast
I think I'd adjust my rev limit if I was you.
#26
TECH Senior Member
Fair enough! I guess I heard the few horror stories about it then thought it was more common than it is.
#28
TECH Senior Member
You OK??
#29
ModSquad
iTrader: (6)
Holy cow man! I’ve heard of this, but never seen it happen. What clutch/flywheel? Is the truck totaled? Are you ok?
#30
TECH Enthusiast
I apologise for hijacking this this thread. So I deleted my last posts . That was rude of me. I'll start my own thread on (show me the Carnage) again sorry for being a dick... In the future I'll try not to do that ****.
#32
I hear of this, but I have yet to see it and NO ONE runs their cars harder than I do. I've spun my 6.2L over 9 grand a few times, and over 8000 countless times, stock rockers, no issue, 0.600" lift. I have installed cams as big as 0.630 lift but now mostly install cams in the 0..560" lift range. A few ponies only available past 6500 RPM dont interest me, and nor should they anyone else unless you are class racing? Add cubes or boost. Leave the donkey dink cams to the ones who tear apart engines every weekend
#33
Yeah, but at least the force on a connecting rod bushing in constantly (and rapidly) changing direction, potentially helping with oiling. A rocker bushing always has the force coming from one direction, constantly pushing oil out. Just something to think about. I'm not sold on bushings for rockers unless they're pressure fed oil even though I am running a set of Straubs (or whoever actually makes them).
#34
TECH Veteran
iTrader: (40)
Yeah, but at least the force on a connecting rod bushing in constantly (and rapidly) changing direction, potentially helping with oiling. A rocker bushing always has the force coming from one direction, constantly pushing oil out. Just something to think about. I'm not sold on bushings for rockers unless they're pressure fed oil even though I am running a set of Straubs (or whoever actually makes them).
Rod bearings are oiled by oil splash from the crank spinning, they don't have dedicated oililng, makes it a super similar situation to the rockers.
Last edited by 00pooterSS; 12-04-2018 at 08:58 PM.
#35
TECH Senior Member
Aren't there oil passages in the crank from the mains to the rod journals? Isn't that what the holes in the crank journals are for?
#36
Force on one side or both sides doesn't change the theory of pushing oil out. By your theory everything in the engine is pushing oil out, which it does. Having a film of oil coating is all that's really important.
Rod bearings are oiled by oil splash from the crank spinning, they don't have dedicated oililng, makes it a super similar situation to the rockers.
Rod bearings are oiled by oil splash from the crank spinning, they don't have dedicated oililng, makes it a super similar situation to the rockers.
#37
TECH Veteran
iTrader: (40)
My brain is fried this past week. I keep screwing things up and having to edit.
Some pins have no dedicating oiling besides splash.
Forced feed is usually from the piston rings pushing oil through oil passages in the piston oil ring groove over to the wrist pin. And you'll get some oil from splash and piston squirters too if you have them.
There are some rods that are drilled and even some funky ones where they cut grooves in the sides of the big end of the rod to create oil spray that will shoot up at the piston and rod. But that I'm aware of it isn't an OE thing, and is rare even in aftermarket.
Some pins have no dedicating oiling besides splash.
Forced feed is usually from the piston rings pushing oil through oil passages in the piston oil ring groove over to the wrist pin. And you'll get some oil from splash and piston squirters too if you have them.
There are some rods that are drilled and even some funky ones where they cut grooves in the sides of the big end of the rod to create oil spray that will shoot up at the piston and rod. But that I'm aware of it isn't an OE thing, and is rare even in aftermarket.
Last edited by 00pooterSS; 12-04-2018 at 09:00 PM.
#39
TECH Veteran
iTrader: (40)
Another way to picture it is to picture press fit pins, they press into the rod and float in the piston, if there was any oiling through the rod it would get sealed off my the press fit of the pin.
So if there's any force oiling through the rod it would have to be a floating pin style. I think there is a manufacturer that drills rods but mostly no that's not how it's done.
#40
TECH Veteran
iTrader: (40)
G. --- I just realized I never made it clear I was talking about the small end of the rod. When I said bushing in the rod originally I was talking about small end bushing. Which I assumed was clear. Then I compared rod bearings to bushings making everything clear as mud.
Then me confusing you made you confuse me
So my original statement should read ----- If bushings can live in rods with having splash oiling over the wrist pin and rod bushing, then rocker arms using bushings should hold up just as well or better with their splash oiling. And look how long rod bushings last, and to be clear, i'm referring to the bushing in the small end. Not the bearing in the big end at the crank.
Then me confusing you made you confuse me
So my original statement should read ----- If bushings can live in rods with having splash oiling over the wrist pin and rod bushing, then rocker arms using bushings should hold up just as well or better with their splash oiling. And look how long rod bushings last, and to be clear, i'm referring to the bushing in the small end. Not the bearing in the big end at the crank.