11:49:18pm, Thursday, April 18, 2024
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Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
Broken........ that's just me ! just started our 11th season with a 466 JD and have bearing trouble again!!!!!!!!! grrrrr! It has occurred to me that the one part remaining unchanged during all this time is the harmonic balancer, could this be causing our bearing failure every time we go down the track????
Has anyone had similar experience? Line bored, girdled, small pin rods, stroked crank, light pistons, balanced crank, aviaid pump, runs 120psi oil pressure down the track, deep sump, clearances are 5 & 6. Not even running strong. cam timing 102, 13mm p pump 52. 5500 rpm. Are JD balancers directional ? next step is to fit a new balancer if the crank is salvageable? running out of ideas and confidence! Never the same bearing twice, could be a main or a big end or both ! Help! |
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Re: Engine bearing failure
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LLSS
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Had problems with clutch coming loose and every year crank was bent. Put on a good fluid dampener and all went away. |
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Re: Engine bearing failure
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sbjd
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What's your email |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
alex@nethertontractors Edited 1 time(s). Last edit at 05/21/2014 02:52AM by pistnbroke. |
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Re: Engine bearing failure
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Registered: 07/11/2008 Posts: 326 |
What brand bearings? |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
clevite |
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Re: Engine bearing failure
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boozen binder
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If your engine still has the filter bypass it could be the 120psi is popping it off letting unfiltered oil go threw the engine |
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Re: Engine bearing failure
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Registered: 11/26/2011 Posts: 66 |
like LLSS said. I had a straight 6 Pontiac in a mini, and the converter, flex plate bolts would always work their loose. put a good fluid damper on it and NEVER had that problem again!! I was very happy! |
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Re: Engine bearing failure
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Get a new fluid balancer to start seems like
A lot of oil pressure to me. What are u using For oil??? |
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Re: Engine bearing failure
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pressure
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Could be your washing out the bearings. If you remove the bypass you will have to be careful you don't try to push too much oil through the filters as they will implode inside. Some filters have the bypass built in the filter and some systems have the bypass in the engine. Pro Stock pullers used to walk around like a deers eyes in the headlights. The were trying to push too thick of oil through a filter on a cold day and collapse the filter. If you can crank the engine slow; don't start: until; you have max pressure at the top of the engine the filter will not collapse.. Let the oil run back into the pan and the filters will collapse.The filter will survive as long as the pressure is equal on both sides of it.
Post pictures of bearings, without photos it's a guess. I cannot see a balance destroying rod and mains bearings. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
I reply to the last few posts- Oil is Kendal 20/50. There is no oil bypass on the engine, oil goes straight through a 1 1/2" supply hose into the gallery which has been washed out to allow better flow. Oberg filter bypass is also locked off to cancel any unfiltered oil entry.
According to Aviaid pumps people there is no such thing as too high oil pressure, there words not mine! Have burst a couple obergs in the past before fitting an external relief valve. The relief valve in the aviaid pump seems to not flow enough oil to cope. Crank should be out tonight, I will post some photos then. thanks |
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Re: Engine bearing failure
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pressure
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Sounds you misunderstood what Avaid said. Too much pressure will washout the bearing surface.It looks like erosion. There's a lot of garbage in that filter. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
Aviaid guy definitely said 'too high oil pressure is a myth' they have race engines running 300psi! |
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Re: Engine bearing failure
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pressure
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And how many revolutions do they turn before they are torn down? He's only telling you one side of the story. One things for sure, you are doing something wrong. Maybe your Aviaid guy is who you should be talking to. The rest of us obviously don't have a clue. Clearances are a factor with pressure. Making a blanket statement that pressure has no effect is unrealistic. |
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Re: Engine bearing failure
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forest gump
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I AM A FIRM BELIEVER IN CLOSE TO STOCK.
we used one of those filters once and other type. as for bypasses UNFILTERED OIL IS BETTER THEN THE LACK OF. some filters just does not allow the flow. like that screen one. they are great if there is nothing to really clean but if there is some flaking of anything or just cleaning what we call lint it could lay flat on the surface causing just enough restitution to cause issues. this could also cause if you pump has one do a internal bypass. with some of the larger clearances we are running today a little unfiltered oil is better then none. if you have something wrong going on plugging those filters makes it much harder to find as no oil will take out allot. also do not like the long screen filter that has the fram HP1 filter top on iy with the 4x4 screen on top. that screen on the top is the bighest down fall. you are tring to put all that oil thru that little area is nuts. AND THAT IS ALL I GOT TO SAY ABOUT THAT |
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Re: Engine bearing failure
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Cranky
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You said your crank was balanced, is it counter balanced or counterweighted?
There are 2 or more counterweights missing from a stock crank. This is to aide in cost of manufacturing. They need to be added back on to keep the crank from flexing under load. |
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Re: Engine bearing failure
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LSS Puller
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Oil pressure being too high is not going to be your issue. We run 170 psi down the track and have never had bearing issues. |
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Re: Engine bearing failure
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Do u have a pressure regulator ur running good
Oil we run a pro and don't ever get that high Of pressure to much will just blow it passed bearings |
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Re: Engine bearing failure
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pressure
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Where are you measuring the oil pressure? |
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Re: Engine bearing failure
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Misc part
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We had the same issue with a diesel and alcohol. What we found on the diesel was the oil filter was collapsing and starving the motor with oil. So we went to a Holley oil filter and solved the issue with that one. On the Alcohol, we had a holley oil filter assembly. What we found is that the pressure from the avid pump would drop and I think we ended up putting a stronger relief spring in the pump and didn't have an issue after that. If I remember correctly it was in the pump returning too much oil at a higher RPMS. Had good oil pressure at idle, but when the engine speed up the oil pressure dropped and would take out all the brgs. |
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Re: Engine bearing failure
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IH-SSD
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Oil pressure in my opinion is not the problem we run 200 to 250. For us it is the dry starts that that hurt it. We always hold the shut off tell it builds oil pressure then let it start. If the filter is empty we prepressure the system before first start on new oil or after checking filter. Another thing if you are 5-6 on your crank to bearing clearance you may be to loose for the rpm you are carrying down the track. on a 466 I would be closer to a 3-4. If you run it really loose as we do you will need to be very high with your oil pressure. The looser we made ours the higher we had to go to keep bearings in it. |
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Re: Engine bearing failure
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Posts: 744 |
I agree it seemed a little loose on clearances for application as well. Not that it cant work but maybe not needed in your scenario of rpms and boost your are running.
We run higher than that on oil pressure as well and never washed bearings. So I highly doubt that is your issue. Have you tried coated bearings or are these clevites coated already? And when you give clearances did you check them on assembly or trust the shop or part supplier? Not saying you have any issue but many can attest to discrepancies on what was ordered and how it really fit upon assembly. Nothing worse than chasing bottom end issues hope you find the cause. COO for OTTPA www.outlawpulling.com www.truck-specialties.com Schaeffer Oil Representative [www.schaefferoil.com] |
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Re: Engine bearing failure
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Same as Misc part
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I agree with Misc parts comment, when our engine would hit higher RPM's the oil pressure would drop quite a bit and it would take out the center main bearings, then we put a higher pressure spring in our aviaid pump and no more problems. Every time we had this problem we had the aviaid pump checked out by avid and they said it was ok. Finally we put a oil pressure sensor on our recorder and discovered the problem. We run 110-120 PSI and have never had bearing problems since putting in the higher pressure spring running it at these pressures. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
interesting on the pump relief spring. we do run the light spring but have no data recorder. Also interesting is that the Oberg might not flow enough oil at higher rpms ? This is all beginning to make food for thought. a simple oil pressure data recorder would be good I think. As for the Oberg bypass- we have been wrecking bearings for years before closing off the bypass with no noticeable difference.
The crank has no extra balance weights added. Oil pressure is measured off the end of the oil gallery which I guess is where the farm tractor take off was fitted? We always crank with no fuel until the oil pressure comes up and always prime the system with a belt on the cordless drill when the system is dry before starting. We have fitted a pressure regulator to reduce peak pressure when cold. thanks |
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Re: Engine bearing failure
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Registered: 03/31/2008 Posts: 762 |
So in this case it was #2 rod? Are all of the mains Ok this time? Is it typically rods & not mains?
Yes, data recorder to see what the pressure is doing would be good. Also, look at the path the oil has to take and see if you can find a plug in the block at or near the end of the path. That will give you an idea how much pressure drop there is in the passages in the block. |
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Re: Engine bearing failure
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WI Boy
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I had the same issue on my Heavy Super. It would always come down to bearing and I would have about that much debris in my filter as well. I could never figure it out. I would only make it about 6 passes before the bearings would go south. If it was me I would look at the oil then the balancer. |
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Re: Engine bearing failure
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funny
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Boys oil holes are drilled in the center of the journels 50 psi or 200 is a solid stream as the crank goes round and round the blowout deal is a joke |
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Re: Engine bearing failure
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Posts: 198 |
Are you starting with either A LOT?? |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
Hotsmallblock- never use ether after breaking a piston on a great going old ford years ago. Heat up the water and put propane torch in the air intake- much smoother start. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
after discussion with a friend last night- I have drilled into the main that carries the thrust washer to get oil onto thrust washer, could this be where we are losing pressure? we are also utilising piston spray jets. Maybe there is not enough pressure left to feed the big end with spray jet, thrust feed and big clearances?? just thinking?
thrust oil feed is 2mm |
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Re: Engine bearing failure
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Registered: 07/11/2008 Posts: 326 |
I sure wouldn't think 2mm would affect it.. and I think you said it's a different bearing every time.. Or does it get the thrust every time with another bearing?? I couldn't exactly tell from the pics, if it was the thrust this time.. One picture it looked like it was.. then the picture with all 7 caps it didn't...
I actually like your idea of the extra oil the the thrust.. I'm guessing you only drilled it to one side of the thrust? |
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Re: Engine bearing failure
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IH-SSD
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I would tighten up your clearance's you said 5-6 on clearance if you are that loose with out being over 200psi you are not getting oil to the rod bearing's you are loosing it at the main bearing. With a lot of oil clearance you need a lot of oil and a lot of pressure to keep the bearing from wearing. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
funny- sorry, not sure what you mean ? Edited 1 time(s). Last edit at 05/26/2014 07:26PM by pistnbroke. |
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Re: Engine bearing failure
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RPM wobble
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Way to much clearance--turn crank to install .010 over bearings. Let the crank grinder determine the clearance--it will probably be .002 or .003 max. Install a GOOD balancer with a taper lock hub! The JD balancer is not designed for 5500 RPM. (the crank is not either!!!) The crank is making contact with the bearing, that is why you are tearing it up. That crank is wobbling around an unbelieveable amount--thats why you are destroying different bearings. You should have only drilled a small hole on the clutch side of the thrust bearing (the clutch side) not both sides. With proper bearing clearances, that will be ok but was not necessary. Do you have an aftermarket transmission? If so, when it was installed, did you make sure the clutch shaft had clearance between the coupler and top shaft in the trans, and the shaft nose bearing in the back of the crank? If that is tight, you will push the crank tight to the thrust bearing and take it out no matter if you are oiling it with your hole or not. There has to be clearance, .030 or so. The clutch shaft cannot put any pressure on the crank. It is up to the installer to check this. With your bearing clearances, at high RPM you will loose oil pressure. Another question--why do you come out at 5500 RPM? Is this an RPM contest, or a pulling contest? I have pulled for 20 years with a JD and have used the same rod and crank bearings for 5 to 6 years without a problem. Your setup is way wrong if you take out the bearings after 1 pass. Correct what you are doing, and have fun pulling instead of wrenching. |
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Re: Engine bearing failure
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ss
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Man these old JD and IH and AC have been turning 5 or 6 thousand RPMs for 40 years without the extra weight added to the crank Hell the Buda ,Wakasha , Case ,and Perkins don't have any counter weights .I love BEATTING you guys high doller CRAP .And that's the bottom line |
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Re: Engine bearing failure
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SSk44
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And by the way the faster the oil pump turns the more pressure it will make not less |
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Re: Engine bearing failure
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Registered: 07/08/2013 Posts: 60 |
What spring are you guys running on the pump. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
light spring to try and relieve excess oil pressure |
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Re: Engine bearing failure
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Cranky
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Dollar signs don't change math.
Today's (and yesterday's) Diesel engines need counterweights. I see it in Tier IV over the road and rail road diesel as well. Increased cylinder pressure has put extra stress on the crankshaft. Heavier rods and pistons don't help. You have been fortunate to run your setup as is without said "Extra weight welded to the crank". |
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Re: Engine bearing failure
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food for thought
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maybe the block is distorted? I had a rear main issue with a 4x4 gas 454 block. bearings and thrust problems.
Long story short . too much hp for stock block. 850 HP. Changed block Problems went away. Just some thoughts. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
Hi RPM wobble- thanks for info. Thrust oil feed is only drilled on clutch side as you suggested and there is plenty of end float available on gearbox input shaft and crank when connected. Crank journal clearances are 2 & 3 thou as standard on this engine, is this enough ? we have been there before and ripped the bearings out as well. The most success we have ever had is with larger clearances albeit not a complete solution. I am interested in what you are saying though as I am not a trained engineer. Our crank grinder is not comfortable with the large clearances either, although they have no tractor pulling experience, they do have plenty race car engine experience.
reply to JGnut- Yes we have had 2 years of taking out the thrust and any other bearing on two different blocks. I am planning to fit an insert to reduce 2mm thrust feed to 0.5mm to increase oil availability for this journal and big end. We are currently running p pump timing at 52 degrees- what are you guys out there running succesfuly?? This is not working for us currently. |
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Re: Engine bearing failure
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RPM wobble
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What class are you in? What size turbo? Do you run diesel or B-100? What cubic inch? If you are hot farm/Superfarm/any restricted turbo class, you are running to much RPM (small turbo cannot make horsepower at high RPM) AND way to much timing, especially if you put cetane in your diesel fuel. You need to find a good starting baseline: Diesel fuel with over the counter fuel lube; timing at 36 degrees; max rpm coming off the line 4500 RPM; plus reasonable clearances in rod/main bearings, instead of excessive cleasrances; a taperlock hub with 12 inch balancer. This should make this thing run real good, make small adjustments from this starting point. In reference to the comment that "high rpm turns pump faster = increased oil pressure, not lower oil pressure", excessive bearing clearance definately will cause the oil pressure to fall to dangerously low pressure at high RPM. Google something like "valve spring video at high rpm" and watch what happens to valves and valve springs at high rpm, then form a mental picture of what your very heavy crank/rod/pistons are doing at high RPM. I think you will understand what I am talking about. Stuff moves all over the place at high RPM. I realize 5500 RPM is not "high RPM in the car racing world", but car stuff is light, and runs a lot lower compression, and uses a slower burning fuel. Good luck with your project. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
Hi RPM wobble. Thanks for your time and info.
Crank back from grinder last night, turns out, I gave wrong info on clearances. Correct clearances are 3 and 4. No 5 big end is now -20 and the rest all received a polish. Engine is 466 with a stroked crank running 504" in Pro stock class, with 13mm p pump, crane roller cam, standard fuel, big valve head, standard diesel, 4.1 hypermax turbo. I have reduced the oil supply to the thrust washer down to 1mm and I am going to plug the spray jet for this piston to keep more oil on the journals . thanks |
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Re: Engine bearing failure
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RPM wobble
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What is your email or contact info? The spray jet cools the piston and lubes the pin. Probably not a good idea to plug that. |
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Re: Engine bearing failure
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Registered: 02/28/2013 Posts: 28 |
alex@nethertontractors Edited 1 time(s). Last edit at 05/30/2014 05:57AM by pistnbroke. |
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