Questions about 318 LA Bearings....??

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225Cuda

225Cuda

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OK I have taken the bottom end on this LA 318 30 over 10 under Motor I bought for 200 bucks the guy I bought it from said it had a knock so i tore it down on the bottom end and noticed that all the bearings look good and one of my friends told me about thrust bearings, now on the LA motors is there supposed to be a thrust bearing on the front, the back, or both ends from what I can see on the motor I do not see a thrust bearing there I will take pics tomorrow when I have more light, I checked all main cap, bearings, rod bearings, and all bearings on the bottom end and the looked great they are 10 undersized though don't know if that huts anything, Let me know what y'all know.

Thanks,
 
The third main back from the front is the thrust bearing. I should be obvious which one it is.
 
Ill take pictures to show my problem cause all the bearings look the same except the last one and it is just wider.
 
3rd Main has the thrust bearings on either side. It's "C" shaped when looked at from the side. The others are just flat.
 
It will look like this when pulled out of the block or main cap.
 

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225Cuda said:
Ill take pictures to show my problem cause all the bearings look the same except the last one and it is just wider.
Click to expand...


The last one is supposed to be wider...

And the middle one (#3) has the flanges on the front and rear of the bearing for the thrust surfaces....
 
OK I just check and it does have the thrust bearing in it so I am back to trying to figure out where this supposed "knock" is coming from.
 
I am contemplating just putting it back together and running it to see if I can diagnose by ear where the "noise" is coming from...
 
Check for a bad wrist pin on the pistons.
What shape are the bearings in?
 
They look brand new no scaring,what would be a sign of a bad wrist pin from underneath the piston.
 
maybe a piston is loose , are the piston pins off set or on center?
 
plastigage the bearings before assembling. then you will know if they are correct. don't guess. might find a wrong size bearing in there?? look for cracked piston skirts also.
 
I see youre into the mains, but no mention of the rods?
Rods are usually the knockers. Start with # 1 and #7, or any rod that doesnt move sideways, making nice clicking sounds between the adjacent rod and the crank shoulder,Or any rod that has babbet squeezing out the side.
And for goodness sake dont slap it together and see what happens.
 
Well my only problem is they took the motor out of the car it only has 4000 miles on the rebuild and the person I bought it from said it was knocking and the shop pulled it out with out doing a diagnosis of the problem so I am going through all the possibilities of the culprit but have not found anything oh and BTW all rod bearings look brand new with no scaring
 
Check the thrust, it may be out of spec. If all else is OK then go to the small end of the rods and look for issues there. Do you know if the pins are pressed or floaters?

Bob
 
If its' a noise, it can be found. But - you may need to investigate more. Pure stupid to put it together to see if you can hear it. Take it all apart, check everything, hoepfully you find something. If you do find something, fix it. If you can't find anything, it's probably the wrist pin(s) and you can replace the pistons, then put it all back.
 
my 318 had conrod bearing failure. higher rpm it sounded like someone hammered my engine, ticking sound.
 
I will check the conrods to pistons this weekend, the original owner said it started "knocking" about a week after the intake manifold gasket was repaired from a coolant leak.
 
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