Any ideas what this Cause of hurt bearings? Pics inside.

Discussion in 'PSI Superchargers Tech Questions' started by gmhpwr, Aug 10, 2018.

  1. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    A few thoughts -

    First thing I would check and always keep an eye on with a hemi is oil pressure in shutdown. Especially if you are not able to get the car into a neutral state. Wear on the bottom bearing is almost always lack of oil in shutdown because decel is where it sees most of its load. It might be better to configure your accumulator for shutdown.

    Make sure you have the right micron filter for heavy oil.

    50 wt oil is a little thin for the summer months in my opinion. Especially if you are rich. Could be as simple as diluted oil. Especially if making multiple runs on the same batch.

    If the crank was recently turned down .010, was it checked for straightness after you got that one journal hot?
     
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  2. jay70cuda

    jay70cuda Well-Known Member

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    I blew up a couple of engines from a bad oil tank design that as soon as the decel happened it starved the bearings at high rpm for oil. Looking at the plugs, a/f ratio and timing everyone was like your plenty safe then BOOM! Out goes a rod. Fix it and repeat. 3 times to be exact! Kill it in the lights , get the engine to let go of the converter or clutch watch the oil psi during the run, and after. They should be working together.
     
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  3. sean70ss

    sean70ss Member

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    1.LINE HONE issue cap movement possibly
    2.Crank flex/cracked
    2.Wrong bearings
    4.How old is that block?
     
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  4. drew556

    drew556 Member

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    Did you prime the oil system with a drill motor manually turning the oil pump prior to the first start up ?
     
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  5. promodracer

    promodracer Member

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    lol
     
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  6. mogenss

    mogenss Member

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    This is what we do before startup, Im not saying that it is perfect or anything like that
    1) heat the oil
    2) grease pushrods, lube valve train, set valves
    3) spin the engine over with no plugs and build oil pressure
    4) put plugs in and start
     
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  7. gmhpwr

    gmhpwr New Member

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    thanks for all the help and advice guys, as I said this combo is so new to me and I have a lot to learn,
    will hanna, to be honest I don't know the crank was checked for straightness the last time as it was a bit of a rush job to make a big meeting.
    the car has been completely striped and I will have the engine checked over, crank checked for straightness and re crack tested ect .
    one interesting thing I noticed that was mentioned was the correct micron filter to suit the heavy oil. what micron filter would you guys recommend? I am going to buy a Peterson oil primer/filter assembly so I can prime the engine for a period of time prior to firing the engine so I would like to get the correct filter to suit the application.

    jaycuda sounds similar enough to my situation, no rods out but I fell its not far off. everyone looks at my plugs, fuel and timing and say im in the very safe side leaning me towards an oiling issue as such. and the advice of a lot on here has given me great things to check for to.

    the block had been line bored/honed recently( since iv owned it ) as for the blocks age, it is a older kb .100+ block that had been repaired but hence having the block reline bored ect I assumed having it repaired to not be a drama??

    prior to first fire up the engine had 4 quarts of oil pushed throw it to lubricate bearings ect with a friends air primer setup. it tee's into the filter line and pushes oil throw the oil galleries' and oil pressure gauge sat at 40psi throw out that process,(being measured at the rear of the block)

    mogenss I have now got into the habit of lubing the valve train and pushrods before first fire up each time (learnt that the hard way also)
    and have started to heat the oil also, my way of priming was just to crack the oil accumulator but im learning that may not be enough.



    Im looking to buy a new sump/pan for the engine, Olsen look to have a few nice options as such , so do moroso but is there anything in particular I should look for? id like a oringed sealing pan if possible as im redoing the front so the pan can be removed in the car to check bearings ect.
    Id like to stay wet sump for room reasons and from talking to a lot of people I should be able to make a wet pan work well if setup correctly.

    thankyou again
     
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  8. drew556

    drew556 Member

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    Never used an air primer set up sounds like it would work ok we hook up a 1/2 in drive corded electric drill (battery powered don’t have enough power) spin oil pump till it tries to stop the drill motor
     
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  9. Brent

    Brent Member

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    I have the Petersen oil primer / filter assembly and Olson 18 quart Pro Mod pan. Oil primer/ filter assembly works great. Spin it over with my cordless drill, get 60 lbs pressure in 10 seconds with the plugs in. Fire it up. No more winging the motor over to get oil pressure up and no more wear and tear on bearings and the starter.
     
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  10. Policy Peddler

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    Where are you getting your oil pressure readings from? The bearing showing the copper is on the edge, looks like the bearing is too wide. It is on the cap half, with out experience I would expect a cracked crank to squeeze the rod half of the bearing.
    The other bearings look like the oil was wiped off. I like to crank my engine until i get oil pressure before hitting the ignition. All those big diesel engine makers can not be all wrong with their oil pressure lock out when you go to start them. I probably am missing this, but what is your bearing clearance? You might try heavier oil and possibly the actual Brad Penn Oil. The bubbles on the bearings per the head drag racing person at Clevite is from moisture when the bearing was coated. At one time I have several sets like that.
    If you want to cut your bearing usage down, per the same person at Clevite, told me to get them coated with black nitro coating on them at H.M. Elliotte, clevite does not offer it on BBC bearings. I had a oil line come off at full throttle during a 1/3 of a run, and I did not know it until the run was over. The rods were pounded out of round but the bearings did not grab and no broken rods.
    Looking at your pictures again, a couple observations, the first picture, it looks like in one place the rod has rubbed on the filet of the crank. The picture with the copper showing, the bearing material has flowed over the top of the locating pin.
     
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    Last edited: Aug 19, 2018
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  11. jay70cuda

    jay70cuda Well-Known Member

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    Policy peddler can you explain the coating and where to get it from. I’ve dealt with coatings from other companies and the shit falls off and into your oil passages.
     
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  12. TOL

    TOL Active Member

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    I'd like to know more about that coating process too........ Thx.
     
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  13. frank70

    frank70 NOSTALGIA DRAGSTER

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    Just my 2 cents here so go easy on me, but 50W oil seems pretty thin for .005” ( room temperature ) clearance on rod bearings.
     
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  14. Policy Peddler

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    the coating is dome by H.M. Elliot, just google them. I understand that Clevite sells some bearings with the coating already on them. I could not be happier with it. I have had a couple of oil issues in the last 30 yrs. and NEVER had a bearing problem when I had the oiling problem. That is not to say the the bearings were not flattened or the rods not out of round with out the cushioning of the oil. The bearings did not grab the crank and break a rod.
    I run .006 to .007 clearance with 60 wgt brad penn, 85 to 110 # of pressure. My max steady rpm is 7500, this is on a BBC 3 motor pulling tractor. I am not saying this is what people should do but what works for me.
    If my bearings looked like the ones above I would run 60 or 70 wgt oil. is the oil pressure being taken before or after the filter? Before, is there a restriction so the oil does not get to the bearings?
     
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  15. kbhemi

    kbhemi Member

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    change to 70 wt oil - when you have bearings that fall out of the rods - that means you are beating the bearings with the crank - and that makes em collapse - just like a hammer would do to bearings in a v block. Thicker oil will fix that - or use a couple of quarts of lucas oil stabilizer. Larry Jeffers extreme racing oil - is the way to go - I used to change oil at every event - now I go two plus events - and cry when I change the oil - it looks new when I drain it - old habits are hard to change - but painfully good.
     
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  16. td3829mk

    td3829mk Member

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    So no one believes 200+ psi of oil pressure is enough to wash out the bearings?? Seems way too high. The wear pattern on the bearings looks like its from side to side...how wide are your rods? Have you checked your thrust bearing or end play?

    I run 50 wt oil with lucas oil stabilizer and change bearings after 10-15 runs just because..so I'd be slow to think its soley an oil weight problem.

    Also, you believe to be on the "safe" side pushing 1000 on EGTs? Have you tried throwing some more timing at it to cool the motor down? I always thought fuel heads liked around 38 degrees..

    I'm curious to know what others think on all this...
     
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  17. gmhpwr

    gmhpwr New Member

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    I will measure my rod width today, the thrust bearing endplay was around .004" if I recall correct.


    with the comment on timing and egts. as I mentioned this is combo is completly new to me so im happy to take any advice anyone is happy to give but with my old turbo alcohol engine being an more conventional style engine it was happy around 1200F, in saying that I have heard a lot more people run these style engines around 900f? is this correct? and I realistically running this engine to hot as such

    I understand these engines apparently like a lot of timing having such a large chamber, but I guess I got gun shy/scared once I was having problems and pulled timing, could this be creating more problems then good as I do realise more timing will cool the engine (I understand this is a different issue to oiling)

    the car is currently having the front half of the chassis redone to make the oil pan removable in the car to check bearings and also easier to work on so I am just trying to gather as much info as possible prior to finishing the car.

    once again for everyone's input
    thankyou
     
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  18. kosky racing

    kosky racing Comp Eliminator

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    MORE timing to cool the motor down-is this from your findings???
     
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  19. td3829mk

    td3829mk Member

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    Not quite, should have been more specific so I apologize. I'm referring to managing head temp. You've been doing this A LOT longer than I have so maybe you can correct me if I am wrong here. But yes I have found that retarded timing at idle causes higher egts and higher head temp which set me up for failure during the run. If a certain head likes "x" amount of timing that's what it should be run at, correct?
     
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  20. kosky racing

    kosky racing Comp Eliminator

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    Yes correct certain heads like certain amount of timing ex. Fat head 28 Degrees but type mag plays in also and yes retarded timing can cause high egts .-- timing at the max should not be exceeded but for a very short time---there are variables to all tune ups and every type head does have max at certain time -have fun
     
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