bearing trouble February 28, 2013 08:13AM
Hi, looking for some guidance after years of bearing trouble in my stroked (504) 466 JD prostock. every time up the track results in at least one bearing giving in. not always the same bearing, mostly mains but not always. oil pressure runs approx 120psi at start of run at 5500rpm. Bearing clearance = 0'006'. Fitted new block and crank last year from respected engine builder, this did exactly the same as the previous unit. No monitoring system fitted. Dont have deep sump. Does anyone know if windage will cause this trouble? Any help appreciated. Seriously frustrated ! thanks in advance :-) Alex
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Re: bearing trouble February 28, 2013 11:48AM
Give me a call i think i can help you out.
Davey 301 992 4885
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Re: bearing trouble March 02, 2013 05:41AM
ok will do thanks. running kendall oil as well. 8" oberg filter. Ariad 3 stage pump with small section on fuel and both big sections feeding straight into oberg with one 5/8 pipe feeding direct into main oil gallery. very high oil pressure on start up even with light spring in pump relief, have burst a couple of obergs in the past because of this, but when oil is warm pressure seems to run as mentioned above.
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Re: bearing trouble March 02, 2013 11:37AM
Oil pressure is very high. I would get bearing wash when oil pressure was over 100 psi. I adjusted my oil pressure to around 40 idling and around 65 going down the track. Bearing wash was gone and the bearings would last a very long time.
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Re: bearing trouble March 03, 2013 06:22AM
this is all interesting! ariad pump guy said too high oil pressre is a myth! they have funny cars running 300psi! that is what he said when i called!
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Re: bearing trouble March 05, 2013 03:44PM
And your pump man is right about funny cars running 300 psi, but they also change the bearings every run.
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Re: bearing trouble March 02, 2013 11:50AM
How can you identify bearing wash?
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Re: bearing trouble March 02, 2013 01:00PM
.006" bearing clearance sounds excessive to me. You need to be able to float the crank on a film of oil and with that much clearance I doubt you can do that. .006 clerance on a 3" rod journal is like haveing a 1/8" hole to run oil out of.
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Re: bearing trouble March 03, 2013 06:20AM
maybe i wrote the size wrong ? 6 thou was what i meant.
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Re: bearing trouble March 03, 2013 03:28PM
Had a Motor do that and can tell u that u need to counterweight crank. The crank cannot take 5500 without being counterweighted. The crank is flexing and that is what is getting your bearings. It sounds funny but they will flex. Counterweighted the crank and had to have it turned and didn't have anymore problems.
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Re: bearing trouble March 02, 2013 03:33PM
Is your crank shaft counter weighted?
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Re: bearing trouble March 02, 2013 04:01PM
Put a girdle on ur motor j had the same problem till i put one on
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Re: bearing trouble March 03, 2013 06:26AM
No counter weights on crank.
Have tried original block with steel mains and aluminium girdle, then tried a 20mm steel girdle all properly machined line bored and de-stressed. Now on to latest block with original mains, aluminium girdle and spacers!
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Re: bearing trouble March 03, 2013 06:39AM
Did u call Moore's yet?

Most all your good John Deere builders know what your problem is and can help you fix it. Btw no one has given you the answer yet.

Make the call
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Re: bearing trouble March 03, 2013 07:19AM
thanks, planning to make the call tomorrow.
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Re: bearing trouble March 03, 2013 04:23PM
Clevite recommends .001" per inch of crank pin diameter +.0005 max bearing clearnce for a race application. That means for the 3" pin in a Deere you should not be over .0035" on your clearance. With your high oil pressure and excessive clearance it is likely you have lots of oil on the side your oil holes feed to but no oil on the other side.
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Re: bearing trouble March 03, 2013 09:46PM
All good feedback guys thanks. I seem to have had best success with larger clearances, but iam no expert and i take on board what you are saying which agrees with the crank grinding people here in scotland who also think i am running too high clearance and to high oil pressure! Maybe crank flex is also an element as Derek suggests. There was another uk 466 deere had years of trouble without finding an answer. I should try and find out if the new owner has weighted the crank!
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Re: bearing trouble March 04, 2013 11:41AM
i am not very knowledgable on John Deere stuff, but I have seen this problem on more than one occasion with guys running 466 blocks. I don't know what the difference is but going to an 8.1 block seemed to help their problem. I am sure there are plenty of John Deere guys that know what the issue you having is.
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Re: bearing trouble March 05, 2013 02:42PM
Analysis shows that with a cylinder pressure of around 30000psi crank deflection in the mains should be less than .001". If you are experienceing crank flex it should show in your bearings. They would have the lead severely worn off at the edges. I suspect you are getting more of an impact and vibration problem from the excessive clearance. Without the oil holding the crankshaft centered and cusioned it is beating around in the block setting up harmonics and all sorts of problems. Think like a lawn mower blade when its tight it runs smooth, loosen the bolt just a little and all hell breaks loose.
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Re: bearing trouble January 29, 2016 03:35AM
Just to reply with the answer to all the bearing failures for 11 years - We went back to the drawing board and looked at everything we had ever changed/swapped etc, the only two remaining items from 11 years ago were the balancer and the Oberg filter. So, phone call to Phil at riverside - please send a suitable balancer and oil filter (system 1)
which we duly fitted 18 months ago and have never had the sump of since !!
It was the Oberg filter not flowing enough oil !!

Hopefully this article will save someone a heap of money and despair, THROW THE OBERG AWAY and use something with more flow.

Many thanks to all the people who made suggestions and offered solutions

Alex
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Re: bearing trouble January 29, 2016 05:38AM
What size oberg were you running?
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Re: bearing trouble June 04, 2016 05:24AM
8"
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Re: bearing trouble March 14, 2013 04:03AM
Smilingyep, davey and i had a good chat about stuff. He also thought it would be good to speak to phil @ riverside. Thanks everybody!
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Re: bearing trouble March 04, 2013 12:17PM
You are cooking your bearings,what i did and was told to do by a builder was take the upper main bearing halfs and take a file,carefully use the corner and file a small channel across the bearing to let oil out and that will keep the bearings cooler.never had any troubles.
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Re: bearing trouble March 07, 2013 02:53PM
I'd call Phil at riverside before i would call anyone else,not moore's.
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Re: bearing trouble January 29, 2016 12:54PM
Call Riverside.
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Re: bearing trouble January 30, 2016 12:40AM
I know Phil well enough to guarantee he is not interested in teaching you how to solve this problem, unless you are a customer who is spending money with him. Also Phil is not a mystical genius who is the only person who can help you solve the problem. Let's talk more about the way you are sucking up oil out of the pan. I have a feeling herein is your problem. Let's help this guy out instead of trying to keep it a huge secret.
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Re: bearing trouble January 30, 2016 01:13AM
Guys read before you post. Most of these posts are almost 3 years old and the original poster just posted to update everybody that he has already figured out what the problem is.
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