I have a 454 in my WIFES biesemeyer. It would build 70 lbs when it started in within a minute or so it would drop to 20 lbs. I tried multiple filters and then broke down and re-built the motor. I did find 2 spun rod bearings. I cleaned the oil journals replaced the rods and all the bearings. set the bearing clearance at .003 mains and .0026 on the rods. also replace the oil pump w/ a high vol. pump. now I get 55 lbs at start and it drops to 40 lbs. I also cut the oil filter and found some more bearing material in it. I have now pulled the engine apart again and the bearings all look good. what could be doing this to me? could there be more bearing crap stuck in a journal that would cause this much loss in oil presure and still not kill the new bearings? this is not my first engine build but the first time I have ever seen a problem like this.
If you found bearing material in the filter and there's nothing wrong with the new bearings then I would think you didn't get all the junk out?, did you tear down the complete motor and wash it down??. Did you take the new pump apart and check clearances and the relief valve?, is it a Mellings pump?, although they are a very good pump, they are still a production piece, that could explain the difference in pressure?....
GofastRacer:
If you found bearing material in the filter and there's nothing wrong with the new bearings then I would think you didn't get all the junk out?, did you tear down the complete motor and wash it down??. Did you take the new pump apart and check clearances and the relief valve?, is it a Mellings pump?, although they are a very good pump, they are still a production piece, that could explain the difference in pressure?.... I flush the oil journals and wash the block. yes it is a mellings pump, I have tried both the old pump and the new one. after the re-build the old pump was only getting 50lbs vs. 70lbs before the new build. the new pump is giving me a little more and only drops 15lbs vs. the old pump dropping 25 lbs
The oil pressure drop before was probably due to the spun bearings?, 50 vs. 70 lbs, sounds like maybe the clearance between the gears and the cover is exccessive, very common on a Melling pump, the relief valve spring may not have the same tension as the old pump also?. Is your new bearings have the same clearance as before?. BTW, what kind of oil filter are you using?..
GofastRacer:
The oil pressure drop before was probably due to the spun bearings?, 50 vs. 70 lbs, sounds like maybe the clearance between the gears and the cover is exccessive, very common on a Melling pump, the relief valve spring may not have the same tension as the old pump also?. Is your new bearings have the same clearance as before?. BTW, what kind of oil filter are you using?.. the 70 to 50 dif. was w/ the same pump. the new pump gave me 5 more lbs. the bearing clearance is tighter than the old bearings. I have used the fram hp and another performance filter as well (can't remember the other filter). If you build a motor, use the same pump and loose 20 lbs of oil pres. what would that tell you? The only thing I can think of is somthing is blocking a oil journal. I just cant think of a place that can build up that much crap to plug it up. or is it something else??????
Well, if it was me I wouldn't beat my head over it, I would tear it down and start over, something got overlooked somewhere and it's not worth taking a chance on it!..Just my .02 for whatever it's worth!..
GOFAST thanks for the thoughts. I think I will send the block to the machine shop for a bath and see if they can find anything. So far everyone I talked to has never seen or heard of a problem like this. My wife thinks it's a gremlin or somethin and we should through the motor away and start over.
That sounds like the best idea.....Can you throw it all the way to Atlanta?
Sounds like a good Hot Tank may fix the problem...Is it possible one of the plugs at the cam has come loose or is leaking? They look like a little freeze plug....
mickeyfinn:
That sounds like the best idea.....Can you throw it all the way to Atlanta? Give me a minute..............................
nope, It landed on the engine stand again.
I guess I will try the hot tank next. I feel like I am having unprotected sex. PULL, PRAY AND PUT IT BACK IN!!!!!!!!!
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