Let's discuss cam bearings

Discussion in 'Street/strip 400/430/455' started by bignastyGS, Dec 18, 2021.

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  1. Tom Righter

    Tom Righter Well-Known Member

    As said in a recent post the TA coating compared to the calico coatings there’s no comparison. What the coating is therefore is to provide a level of protection against contact during break in and when engine has not run for a while,dry start up.I prefer to groove the block in number one and two through five I drill a 1/8 hole into the driver side Lifter galley. I then clock the bearing so I’m feeding at three to 4 o’clock position and 7 o’clock position which is always Where the bearing shows the most contact.Jon Kasse uses somewhat of a similar set up on the 460 Fords and stead of bearings grooved on the back side.If you don’t believe in coatings just look at all the top engine builders they use them throughout the engine.They are not a cure for poor machine work or assembly however provide a degree of forgiveness.
     
    Last edited: Feb 4, 2022
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  2. BQUICK

    BQUICK Gold Level Contributor

    I know my Jag motor would be a goner without coated bearings. Oil line rubbed against header in pits due to grass being long and made a pass with only a couple qts of oil and 20psi at 6500.
     
  3. Tom Righter

    Tom Righter Well-Known Member

    Yep, the coating did its job. And one other important fact to consider with our Buicks as far as the cam bearings go is the small diameter of our Cams. With higher spring pressures The cam is like a wet noodle flexing!so you are going to have contact with the Bearing.
     
  4. Jim Weise

    Jim Weise EFI/DIS 482

    Rich,
    I have no data to support the idea that the grooves in the front bearing won't supply enough oil to the driver side lifter galley. Built well over 100 motors with them now, and a lot of them have had very quiet valve-trains. Even at 600 rpm idle speeds.

    I think if you do the math, on the two back grooves, vs the one cam journal groove, the two back grooves in the bearing actually provides more square inches of passageway for oil. And behind the bearing, it is not subject to trying push the oil against the spinning camshaft.
    ------------------------------------------
    As far as coatings going, I have used them in the past, and continue to use them, but aside from the piston skirt coating applied by Line2Line coatings out in MI, that is used for sizing needs, I have yet to see any bearing coating that simply does not wear off in the contact areas. I have used all the major coaters, plus done it myself in the past.

    Bottom line, I am not having any bearing issues, so I am not looking for solutions. Sure the "top" engine builders all use it.. I has a wonderful profit margin, and is the easiest sale in the world.

    You may call me jaded, but I prefer the term realistic. Most of my peers in the industry do not use coated bearings, unless they are trying to maximize the profit margin on each engine. And the majority of them will give you the same answer as me..

    Yes, they can be helpful during initial startup and break-in, but they are not required.

    I have built dozens of Buick 455 based engines from 350 to nearly 1400 HP, and have not had a bearing failure issue. Dozens of these engine were Hi spring pressure solid flat tappet or solid roller cam 600+ race motors, with the buick cam tunnel.

    -------------------

    Tom, I am curious.. I assume your using the BT-9 bearing from Durabond.. Or are you having the BP-9's coated individually.

    As far as oiling, you say your putting oil in at the 7'oclock postion? There might be a hole there, but I really doubt it will actually oil there. 5-7 is the highest point of contact, and the hydrodynamic wedge is under the greatest pressure there. I very much doubt that 70psi of oil pressure will break into the wedge there. I assume your drill another hole in the bearing to do this? and then using the larger hole drilled by durabond to line up with you hole drilled into the driver side galley.

    Your must be putting quite the groove in the front journal, to get oil around there fast enough to go all the way down the driver side lifter galley, and feed the cam bearings thru a .062 hole.

    I can see all kinds of situations where this could be problematic, in relation to cold engine oil viscosity slowing down the oil feed to the bearings.

    You must have to be awful careful about oil temp with that setup. I can see where a coated bearing would be required here. Intermittent dry lube conditions are the best reason to coat bearings.

    JW
     
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  5. Tom Righter

    Tom Righter Well-Known Member

    Jim, I order the front bearings with the 2 slots from Cleavite their performance material. I’ve had a decent supply of them however it’s dwindling from the last I heard they are not selling them individually anymore. I would then send them to calico and have them coated.As far as the groove at the top of number 1 I can tell you that it’s a lot more than the grooved bearings TA sells.You’re counting on those bearings to provide the oil and that’s one of the reasons why I don’t care for them. But if they work for you that’s great. I’ve been doing my set up for a long time and since doing it have never had a problem. Even on my race motor that made over 800 hp when taken apart the bearings looked new.Once I drill that hole in the galley you have to drag it down a little bit with a small round carbide tool on a Dremel so you can hit the three to 4 o’clock. As far as the 7 o’clock position I believe that long slot Is like a oil reservoir and keeps oil at that critical load area. And I don’t catch all of the slot on the factory oil hole so I don’t bleed off too much oil. I also don’t beat them in, I have a to0l that draws them in so I can be very precise at where I locate them .Like I said it’s worked for me. The dura bond I recently got I don’t care for the 2 large round holes so if I use them I put them in a mill and use a 3/16 and mill a slot in them where I want to. I also like not having to count on buying custom bearings. So once I do all the modifications to the block I never have to buy a special bearing. Take a look at Jessel‘s race cam bearings they use three .062 holes. With one large groove in the back. There’s more than one way to get to the top of the mountain as long as you get there right! Happy holidays!
     
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  6. BQUICK

    BQUICK Gold Level Contributor

    I hear ya Jim....in an ideal world coating not needed but one time I got shutdown after my burnout a couple yrs ago due to something on the track. The starter comes over and starts talking to me then all of a sudden track is clear and they motion me to the line. Got kinda flustered....Make pass and forgot to turn water pump on. Turn it on and needle wraps all the way around on gauge. Maybe oil didn't get that hot but the block sure did and I bet those cam bearings were tight! They seemed to survive which again I attribute to coating. Maybe maybe not....
     
  7. Tom Righter

    Tom Righter Well-Known Member

    Jim, durabond#BP11-1 T that’s all five with 2 holes. Here’s one that I had modified.Clevite #SH 1360 like I said I don’t know if they still offer them.this is the front bearing part number. As far as the groove that I put at the top of the number one it’s .200 wide x about .060 deep.That will move plenty of oil.
     

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  8. Tom Righter

    Tom Righter Well-Known Member

    Jim, your question about the groove being able to supply the driver side lifter galley. Which made me think about the TA bearings. I don’t have one in front of me now but I can’t imagine that groove being more than .020-.030 deep and I don’t know the width So I’ll ask you I can see that working fine on a solid lifter cam but how about on our hydraulic roller where you don’t have the groove in the cam and you’re counting on those grooves in the bearing to supply the oil to the driver side seems to me that could be an issue and create some of the lifter noise because of lack of pressure it’s just a thought. This way of doing cam bearings isn’t anything new it’s been done for years by automotive machine and performance and also there was a write-up in the GS extra probably 25 years ago. Its proven to work. I realize TA’s solution is for people who are not comfortable doing this process.The TA Bearing may work fine for most of the applications but I do question that those grooves can supply enough oil for the hydraulic roller cams In High performance high spring pressure situations. I’d also like to know why this thread is not Marked sticky and also posted in the technical section maybe we can make that happen. Thanks
     
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  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Tom,
    I have the TA bearings along with a hydraulic roller cam. The motor has been together since July of 2012. I originally had the TA supplied Morel roller lifters. They were noisy when hot, both banks. I replaced the Morels with Johnson roller lifters. They are nearly silent. I don't have any valve train noise at all on the driver's side. Just a tiny bit on the passenger side, but the only time I can hear that is with the hood open. Can't hear anything from behind the wheel. I have a balance line, and oil pressure never drops below 20 psi at an in gear 750 RPM idle.

    I can move this thread to the BBB Street strip Forum and make it a sticky.
     
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  10. Tom Righter

    Tom Righter Well-Known Member

    Larry,I use the balance line as well however you’re taking pressure from that side so that side is going to read normal. My question is do you have enough pressure on the driver side to fully pump up the hydraulic lifter as well as feed all the pushrods given the depth and width of the groove on the backside of the TA bearing. On the hydraulic roller there is also a pretty big feed hole that goes to the distributor gear so that is bleeding off some of the pressure that cam bearing feeds to the driver side. Maybe Jim can elaborate on my thoughts.I also understand there definitely was an issue with the morel lifters. Thanks for moving the thread hopefully it helps and gives people more options on their builds
     
    Last edited: Dec 27, 2021
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  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    You're welcome. I can only judge the noise level. The driver's side is dead silent, so I assume the lifters are getting enough oil. I'm only using 1/2 turn pre load.
     
  12. Jim Weise

    Jim Weise EFI/DIS 482

    Tom,

    Next time I have a set of TA cam bearings in my hand, I will measure the grooves for width and depth and do the math.. I had a discussion on this very topic with Mike T when they first came out in their current configuration, and I do recall him saying that there is as much or more area now to move oil, as the groove in the factory camshaft.

    You also have the benefit of sealing the oil passage between the bearing and the block.. we both are doing that, just in different ways.

    As far as what your doing.. I say if it's working for you, then that's great.. go with it.

    If you ask my opinion, I will say your going thru a lot of work and a lot of hassle and expense to fix a problem, that in my mind, does not exist.

    Because like I said, I have lots of experience, and no data to support any idea that the grooves on the front cam bearing are restricting the oiling enough to cause any issue, real-world.

    The current motor I am working on is number 1124.. Larry's was the first HYD roller motor, his is number 1053.. That's 75 motors in the last decade or so, and all but 8 of them were street engines, with hydraulic roller cams, and the ones with the Johnson lifters can be described as "quiet" to "Silent" in the valvetrain. at startup, cold, and warm.

    The issue with the Morel lifters was quality control problems, with the plunger to body clearance. They tried to excuse that by blaming lifter to bore clearance has to be .0015... that was a neat trick, because your not going to find that on nearly any OEM engine, certainly not stuff that's been in service 50+ years.. In fact, I have measured NOS 455 blocks at .002 lifter to bore clearance. The worst set of Morel lifters I think I had was in a Tomahawk block, with the specified oil clearance. You could take the valve covers off, roll the motor over on the starter, and watch the lifters collapse in from full lift, to the base circle, in 5 or 6 seconds. So ridiculous it was laughable. Before and after they were sent back and "cleaned".

    If we had the oil starvation problem you fear, the complaint would be valvetrain noise on the driver side of the engine until it warms up. That complaint is something I have never heard, nor had reported to me, in 67 roller cam 455's, and 350's Buicks that have come off my stand. All with TA cam bearings, and no other cam/lifter specific oil mods. There are hundreds of guys on the board here with hyd roller cams in their small and big blocks, I don't know that I have ever seen a thread with that complaint.

    So I am going to tell you, and anyone else interested, that I see no problem that needs fixing.

    That's not to say what your doing is "wrong" or even that you need to start doing it my way.. but as a builder for the general public, one of my jobs is to deliver the best product, at the best price I can, to offer a good value to the customer. Which in my mind, is installing the TA cam bearings in every high performance build, and at least the front one, in every post 67 Buick V-8 engine.

    JW
     
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  13. Tom Righter

    Tom Righter Well-Known Member

    Thanks for your response Jim, I don’t doubt your results. I like Having options on parts especially now with the supply chain issues that we have to deal with.
     
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  14. Jim Weise

    Jim Weise EFI/DIS 482

    That's true Tom, and if the TA 1559 bearings had not come back in stock recently, I would have had to do what your doing with the front bearing.

    Options are good, and there is more than one way to scale a fish..

    JW
     
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  15. Freakazoid

    Freakazoid Gold Level Contributor

    I am very curious to see what you find when you measure and do the math. Its exactly what I wanted to know.
    The slight drivers side valve train noise at idle, was nothing to worry about. Johnson lifters took care of all the noise on passenger side. Not all on drivers. I just woundered why?
    It was something that I found irritating.
    I have no problem installing a balance line. Im sure that will solve my complaint.
     
  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I don't think a balance line would do anything. It just oils the passenger side galley from front and rear. The driver's side still has to get the oil from across the cam bearing.

    Back in the day, Poston had a line that installed at the back of the block and tied the two galleys together. Lifter Galley Bypass. You can easily make one with commonly available fittings/line. The TA Bearings and discussed modifications made this obsolete.

    LifterGalBypassR.jpg
     
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  17. Jim Weise

    Jim Weise EFI/DIS 482

    While I would never rule out anything, I suspect that lifter bore sizing/location issues might be what your dealing with here.. we just had a big thread on that.

    But by all means, if you have the motor out, tie the galleys together with a line like Larry shows above.. it won't hurt anything.. as long as you don't have some huge hemorrhage on the LH lifter bank.

    If you tie them together, and it drops the oil pressure on the engine, then you know to look for a hemorrhage of oil on the LH lifter bank.

    JW
     
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  18. Tom Righter

    Tom Righter Well-Known Member

    If you used the poston deal you would need some tee in order to still use the balance line. You need to balance the oil pressure to the mains. You would not want to get rid of the balance line.It doesn’t make sense to go through all that with adding another line in the back. The cam bearing modification is simple you can make the groove as deep as you want it in the front. really the width and depth that I described supplies more than enough oil for the driver side. And if you want you could still use the TA cam bearings. The grooved bearing is a good idea except for the fact that the bearing shell is so thin so you can’t really get deep enough without cutting the bearing in half. It makes you wonder why Buick went .030 thicker on the V6 bearing shell and didn’t stick with what they had used all the years on so many different blocks. I could see maybe on that shell you’d be able to go deep enough to supply oil.
     
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  19. Tom Righter

    Tom Righter Well-Known Member

    You can See in the picture the groove that I put in the block. It’s really not that big of a deal to do
     

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  20. BQUICK

    BQUICK Gold Level Contributor

    I just found a box of like new but previously installed teflon coated cam bearings and I had marked it "cam too tight". I seem to remember either using a different coating or non-coated and also had to polish the cam journals down some to finally get cam to turn freely. I wish now that I had written more down but you know how that goes...at the time you think you will never forget.....
     
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