Traditional crankshaft main thrust “bearings” are essentially a bushing… A Torrington bearing is eleventybillion% more effective. It’s become fairly common practice to fit blocks with roller cam bearings. I can guarantee the load forcing that crank forward in the mains is FAR more than what’s happening inside a cam bore… Kevin is a baaaaad man. 🤙
This is why I used to modify the thrust bearing just in case somebody's got a crappy torque converter take no chances. Adding more oil to the rear thrust.
This is really easy, boys. Our engines have TWO different oiling systems, pressurized and SPLASH. The crankshaft bearings are lubricated by the pressurized oiling system and the thrust surface is lubricated by the splash oiling system. The splash oiling system does not work well under high loads when the engine oil is cold, too heavy or when it contaminated with WATER or CONDENSATION. This roller thrust bearing will also be lubricated by the splash oiling system and, as Kevin says, it will be a wear or service item, also. It will last longer than the babbitt thrust bearing because the rollers will hold the engine oil longer than a babbitt thrust bearing since the oil is not being wiped away as it rotates, while loaded.
I was thinking how in the hell do they get a roller bearing past the resr crankshaft flange 💡 then you said front lol. Always learning. Thanks for the help John
Thrust bearing problems are common on Manual trans cars, especially when you put upgraded clutches in them that have high clamp load pressure plates. Every time you step on the clutch, you are shoving or pulling (depending on the type of pressure plate obviously) the crank against the thrust bearings. People don't realize how much thrust force is applied to the crank when you step of the clutch even on a stock low to moderate torque clutch. Add in the fact that in many engines, the thrust bearings are not receiving direct pressure feed oil, (so its easy for them to squeeze out the bit of oil that gets to them and thus start running metal on metal until you take your foot off the clutch pedal) and you have a ticking timebomb of a thrust bearing setup just itching to chew itself up. This is why personally, I've never used upgraded single disc clutches in any of my manual tans cars over the years if one needed more torque holding ability than what the stock clutch could hold. If I need a clutch to hold more torque than the stock clutch could, I would either buy (or build a custom) multi disc clutch with a low clamp force pressure plate to save the thrust bearing in the engine. The last one I did was should have been about to theoretically hold 800lb-ft of torque all day with no issues (was behind an engine that was only making just shy of 650, so was never truly tested to see if actual and theoretical numbers matched) and yet my 5'2, 105lb wife could drive the car in typical rush hour stop and go traffic with no leg fatigue. She even commented the first time she drove the car that it felt almost like she was driving a low power 4cyl manual trans car when it came to clutch pedal effort which is essentially what it should have felt like for the most part because the pressure plate was one that fit several different 4cyl Toyota Cars from (the 80's if memory serves me correctly).
That trust system is the best that's what comes in the rotaries factory and we push those things up to 11,000 RPM between 1500 and 1600 horsepower it never fails
Forget to mention this in my first comment about thrust bearing issues related to manual trans case because of the thrust force during clutch disengagement, but to address the question brought up at 8:25, theoretically, the OE type thust bearing can carry more load than a needle type thrust bearing but there is some caveats that make the lower load carrying needle thrust bearing better suited for the job. First you have to understand that the load carrying capacity of a hydrodynamic bearing (like the OE type engine bearings) is a factor of it's surface area and the oil pressure between the two elements (in this case, the crank and the bearing). Increase either of those two factors and you increase its load carrying capacity (remember, "force" or you could say "counter force" when referencing load carrying is pressure X area). In regards to a needle thrust bearing, Its load capacity is for the most part, finite based almost solely on its dimensions and material and this is where it has the advantage in this type of application despite its lower theoretical load capacity. You see, since oil pressure is a determining factor for the OE type bearings load capacity, its capacity changes dynamically until pressure reaches regulated max BUT (and this is a significant "but"), even when the engine is running at max oil pressure, the thrust bearing face is not seeing nearly that much pressure for one and as load increases, the clearance for oil to get into it decreases and thus the pressure drops as all the oil is squeezed out from the reducing clearance and can't be replenished and ultimately, you go to metal on metal contact. Remember the elementary / middle early science of "path of least resistance" that fluids take when they have options? Well that's what's happening here. The oil that feeds the thrust bearing is bleed-off oil from the main journal adjacent to the thrust bearing (I'm not aware of any engines that have direct feed thrust bearings but that's not to say that there isn't any). As thrust load increases, the crank crank tries to walk and if there is enough oil pressure between the thrust side crank face and the thrust bearing face, the crank can't really walk but there becomes a pressure / force imbalance between the thrust side and none thrust side because you have external forces applying in the thrust direction from either the converter in the cast of auto trans or clutch disengagement in the case of manual trans and you also have oil pressure force that is on the none thrust side of the bearing applying force in the thrust direction because its trying to spread the gap (oil clearance) between the crank and the bearing on the none thrust side which then loads the crank in the thrust direction. This load imbalance causes the crank to start walking in the thrust direction which reduces clearance for more bleed-off oil to get in between the bearing and crank on the thrust side and obviously this increase the clearance for more oil to get in on the none thrust side and remember, "path of least resistance", so the oil from the main will tend to favor bleeding off on the none thrust side since it has less resistance due to increasing clearance from the crank initially walking in the thrust direction. Think of it like this, lets say that you have 2 thou of total thrust clearance, when loads are balanced, each side will have 1 thou clearance and no problems. Then the load becomes unbalanced and the crank starts to walk. If it walked say 1/2 thou, now you have 1/2 thou clearance on the thrust side and 1-1/2 thou clearance on the none thrust side. It will talk more pressure for the oil to try to get into the thrust side so the lesser resistance path is for the oil to bleed off to the non thrust side and since oil cant get in to the thrust side as easy as it can be squeezed out, the clearance gets less and less until metal on metal and toasted thrust bearing and crank. So while a hydrodynamic bearing can carry more load (generally speaking), by the design of an engines bearings and oiling system, the rolling element bearing is better suits since its no susceptible to dynamic change problems like the hydrodynamic bear configuration is.
Wonder if you dimpled the thrust if that would help, you know if your on a tight budget, plus the oil mod you do. Heck maybe do even more oil grooves .
No matter what, reducing friction has got to help. My fear is pressure against the crank in a linear direction compressing it in a manner it’s not designed for. There is a reason the manufacturer puts the thrust bearing closest to the flywheel.
@@squarebit true but in this case the rear thrust won’t be helping to support. The crank will be compressed between the flexplate and the front roller thrust bearing unless the rear thrust is also repaired.
@@JudgeMeNotLeMans The thrust will be controlled by the roller bearing. I fail to see why it would matter if thrust is controlled from #5, #3 (as many used to be) or the #1 main? The crank isn’t going to compress. Most use #5 these days for packaging and production concerns, IMO. It’s probably just easier to machine the rear of the block for the thrust bearing and #1 is occupied by modern crank-driven gerotor oil pumps.
@@JudgeMeNotLeMans I would also think either #1 or #5 main would be better than the #3 main for thrust control for the simple fact that any crank flex/whip will be most exposed on the #3 journal.
@@BC08 Certainly I could be entirely wrong. I was simply making an observation and not from any real world experience. It just seems that a ballooning torque converter applying pressure against the entire length of the crank could potentially be a problem regardless of where the thrust bearing is. That stress has to go somewhere either forward against the crank or rearward towards the transmission and the weak point will be revealed. Also minimizing that stress with torque converter that doesn’t balloon would be an obvious upgrade.
Your comment got me wondering...am I wrong in assuming there is a range of thrust tolerance that the various shafts inside an auto trans would have spec ed? Either from the factory or from an aftermarket source. I know there has to be some movement and I know they talk about clearances when changing the number of clutches/steels inside. I can't think of what else might be moving/pushing. I mean how much "front to back" movement would one expect to have on an installed torque converter? And is it just the torque converter that is moving...? Flex plate bolted to crank, torque converter bolted to flex plate but the torque converter to trans connection is just rotational not front to back so technically it can move, I feel like I am missing something.
The more i see Kevin involved in video's,the more likable the man is.
Very informative videos at the TKM headquarters!
I used torsion bearing thrust bearings on the front and back of my 394 cid sbc 2700hp nitrous motor. 20+ yr ago. Its something that Nascar uses.
How did you get 2700 out of nitrous 394?
@@wi5i413lots of nitrous... lol
Thank you TJ for sharing!!!!! I learn something every time you do build or rebuild of something!!! Good stuff sir!
Traditional crankshaft main thrust “bearings” are essentially a bushing… A Torrington bearing is eleventybillion% more effective. It’s become fairly common practice to fit blocks with roller cam bearings. I can guarantee the load forcing that crank forward in the mains is FAR more than what’s happening inside a cam bore… Kevin is a baaaaad man. 🤙
Thanks for the update John
TKM For the win!
That is so cool how they do that. Ol girl should be really flying when you get it back together.
Can't wait till it's together!
This is why I used to modify the thrust bearing just in case somebody's got a crappy torque converter take no chances. Adding more oil to the rear thrust.
This is really easy, boys. Our engines have TWO different oiling systems, pressurized and SPLASH. The crankshaft bearings are lubricated by the pressurized oiling system and the thrust surface is lubricated by the splash oiling system. The splash oiling system does not work well under high loads when the engine oil is cold, too heavy or when it contaminated with WATER or CONDENSATION. This roller thrust bearing will also be lubricated by the splash oiling system and, as Kevin says, it will be a wear or service item, also. It will last longer than the babbitt thrust bearing because the rollers will hold the engine oil longer than a babbitt thrust bearing since the oil is not being wiped away as it rotates, while loaded.
TKM the world!!!!!🤘🤘🤘🤘👍👍👍👍👍💰💰💰💰💰💰
I was thinking how in the hell do they get a roller bearing past the resr crankshaft flange 💡 then you said front lol. Always learning. Thanks for the help John
Thrust bearing problems are common on Manual trans cars, especially when you put upgraded clutches in them that have high clamp load pressure plates. Every time you step on the clutch, you are shoving or pulling (depending on the type of pressure plate obviously) the crank against the thrust bearings. People don't realize how much thrust force is applied to the crank when you step of the clutch even on a stock low to moderate torque clutch. Add in the fact that in many engines, the thrust bearings are not receiving direct pressure feed oil, (so its easy for them to squeeze out the bit of oil that gets to them and thus start running metal on metal until you take your foot off the clutch pedal) and you have a ticking timebomb of a thrust bearing setup just itching to chew itself up.
This is why personally, I've never used upgraded single disc clutches in any of my manual tans cars over the years if one needed more torque holding ability than what the stock clutch could hold. If I need a clutch to hold more torque than the stock clutch could, I would either buy (or build a custom) multi disc clutch with a low clamp force pressure plate to save the thrust bearing in the engine. The last one I did was should have been about to theoretically hold 800lb-ft of torque all day with no issues (was behind an engine that was only making just shy of 650, so was never truly tested to see if actual and theoretical numbers matched) and yet my 5'2, 105lb wife could drive the car in typical rush hour stop and go traffic with no leg fatigue. She even commented the first time she drove the car that it felt almost like she was driving a low power 4cyl manual trans car when it came to clutch pedal effort which is essentially what it should have felt like for the most part because the pressure plate was one that fit several different 4cyl Toyota Cars from (the 80's if memory serves me correctly).
What kind of mini disc? 7.25 metallic?
"the" Kevin is one smart man, and all round good guy.
Thanks John and Kevin all that stuff is Bad ass what about roller cam bearings
Torrington thrust bearings are the bomb.
Great to see you making little improvements as you go, maybe a complete new set of matching rockers?
Where can we buy the blue TJ shirts?
That trust system is the best that's what comes in the rotaries factory and we push those things up to 11,000 RPM between 1500 and 1600 horsepower it never fails
The Kevin Mullins is an engine god!
Thanks for the video John.
Good Video TJ Kevin Is Smart Man
Bet that drag ill article is good!!! Gonna have to find that!!!!
I had no idea. Good video.
Forget to mention this in my first comment about thrust bearing issues related to manual trans case because of the thrust force during clutch disengagement, but to address the question brought up at 8:25, theoretically, the OE type thust bearing can carry more load than a needle type thrust bearing but there is some caveats that make the lower load carrying needle thrust bearing better suited for the job.
First you have to understand that the load carrying capacity of a hydrodynamic bearing (like the OE type engine bearings) is a factor of it's surface area and the oil pressure between the two elements (in this case, the crank and the bearing). Increase either of those two factors and you increase its load carrying capacity (remember, "force" or you could say "counter force" when referencing load carrying is pressure X area). In regards to a needle thrust bearing, Its load capacity is for the most part, finite based almost solely on its dimensions and material and this is where it has the advantage in this type of application despite its lower theoretical load capacity.
You see, since oil pressure is a determining factor for the OE type bearings load capacity, its capacity changes dynamically until pressure reaches regulated max BUT (and this is a significant "but"), even when the engine is running at max oil pressure, the thrust bearing face is not seeing nearly that much pressure for one and as load increases, the clearance for oil to get into it decreases and thus the pressure drops as all the oil is squeezed out from the reducing clearance and can't be replenished and ultimately, you go to metal on metal contact.
Remember the elementary / middle early science of "path of least resistance" that fluids take when they have options? Well that's what's happening here. The oil that feeds the thrust bearing is bleed-off oil from the main journal adjacent to the thrust bearing (I'm not aware of any engines that have direct feed thrust bearings but that's not to say that there isn't any). As thrust load increases, the crank crank tries to walk and if there is enough oil pressure between the thrust side crank face and the thrust bearing face, the crank can't really walk but there becomes a pressure / force imbalance between the thrust side and none thrust side because you have external forces applying in the thrust direction from either the converter in the cast of auto trans or clutch disengagement in the case of manual trans and you also have oil pressure force that is on the none thrust side of the bearing applying force in the thrust direction because its trying to spread the gap (oil clearance) between the crank and the bearing on the none thrust side which then loads the crank in the thrust direction.
This load imbalance causes the crank to start walking in the thrust direction which reduces clearance for more bleed-off oil to get in between the bearing and crank on the thrust side and obviously this increase the clearance for more oil to get in on the none thrust side and remember, "path of least resistance", so the oil from the main will tend to favor bleeding off on the none thrust side since it has less resistance due to increasing clearance from the crank initially walking in the thrust direction.
Think of it like this, lets say that you have 2 thou of total thrust clearance, when loads are balanced, each side will have 1 thou clearance and no problems. Then the load becomes unbalanced and the crank starts to walk. If it walked say 1/2 thou, now you have 1/2 thou clearance on the thrust side and 1-1/2 thou clearance on the none thrust side. It will talk more pressure for the oil to try to get into the thrust side so the lesser resistance path is for the oil to bleed off to the non thrust side and since oil cant get in to the thrust side as easy as it can be squeezed out, the clearance gets less and less until metal on metal and toasted thrust bearing and crank.
So while a hydrodynamic bearing can carry more load (generally speaking), by the design of an engines bearings and oiling system, the rolling element bearing is better suits since its no susceptible to dynamic change problems like the hydrodynamic bear configuration is.
It would be nice if they could install a rear roller bearing to the crankshaft!🤩🤩🤩🤩
That’s some good insight 👍👍
Works great.. sad most shops dont have a clue how to do this service. Really needed for big power and high trans pressure applications
And they also don't want to try and learn. Seems to me machine chops only want to stick with the ordinary.
Great vid! 💪💪
Dump valves work well to alleviate cooler line pressure. Damm turbos 😂
John you gonna get a pilots license for the new version of the car
Wonder if you dimpled the thrust if that would help, you know if your on a tight budget, plus the oil mod you do. Heck maybe do even more oil grooves .
No matter what, reducing friction has got to help. My fear is pressure against the crank in a linear direction compressing it in a manner it’s not designed for. There is a reason the manufacturer puts the thrust bearing closest to the flywheel.
Nah. Lots of engines have it in different places.
@@squarebit true but in this case the rear thrust won’t be helping to support. The crank will be compressed between the flexplate and the front roller thrust bearing unless the rear thrust is also repaired.
@@JudgeMeNotLeMans The thrust will be controlled by the roller bearing.
I fail to see why it would matter if thrust is controlled from #5, #3 (as many used to be) or the #1 main?
The crank isn’t going to compress.
Most use #5 these days for packaging and production concerns, IMO.
It’s probably just easier to machine the rear of the block for the thrust bearing and #1 is occupied by modern crank-driven gerotor oil pumps.
@@JudgeMeNotLeMans I would also think either #1 or #5 main would be better than the #3 main for thrust control for the simple fact that any crank flex/whip will be most exposed on the #3 journal.
@@BC08 Certainly I could be entirely wrong. I was simply making an observation and not from any real world experience. It just seems that a ballooning torque converter applying pressure against the entire length of the crank could potentially be a problem regardless of where the thrust bearing is. That stress has to go somewhere either forward against the crank or rearward towards the transmission and the weak point will be revealed. Also minimizing that stress with torque converter that doesn’t balloon would be an obvious upgrade.
Will moving the support to the front of the crank cause any deflection or other issues as a result of the converter pressure compressing the crank?
May have a problem with the torque converter internally not shim correctly or something's worn-out.
Can you put a roller thrust on a 351 Windsor I can't find anything about it
Will the roller bearing be lubricated enough just by the oil moving trough the engine?
Do you have the transmission mod done to the pump that helps with the thrush bearing?
What about using a converter charge pressure regulator?
Torrigton bearings are at best a patch. Resolve why the trans is pushing the crank forwards. And No1 main is not near as strong as 5
Your comment got me wondering...am I wrong in assuming there is a range of thrust tolerance that the various shafts inside an auto trans would have spec ed? Either from the factory or from an aftermarket source.
I know there has to be some movement and I know they talk about clearances when changing the number of clutches/steels inside.
I can't think of what else might be moving/pushing. I mean how much "front to back" movement would one expect to have on an installed torque converter? And is it just the torque converter that is moving...?
Flex plate bolted to crank, torque converter bolted to flex plate but the torque converter to trans connection is just rotational not front to back so technically it can move, I feel like I am missing something.
I guess the oil pressure in the trans is trying to push the torque converter out the front of the trans.
Wish I would have done that on my motor I just got done. It’s nitrous so maybe I’m ok.
Any reason you're not welding the crank and utilizing both the standard thrust bearing and the roller?
It would be cheaper to buy another crankshaftv
John kevin still has his red twin turbo hemi SN95 right?
this wont be an issue here soon