Metal in filter

Messages
8
Location
Cali
I recently over-revved my motor (stupid money shift) during a race and am concerned about its health. Redline is 7000rpm, I'm estimating it got to ~9000rpm. This is a "stock" engine that has been re-built probably about 1000-1500 miles ago... All track miles except for ~200miles. I changed the oil, and there was metal in it but no big chunks, just small bits smaller than a grain of sand. Also pulled apart the filter, and there was a little bit in there as well. I decided to run it once more, and re-assess after that. Filled it with Rotella T and a new Napa Gold (Wix) filter. On Saturday, my friend and I put ~200 hard road course miles on it, and ~200 street miles (had to drive the race car home, cause friends car broke so it got my trailer). Burned no oil :-) and the oil looks as clean as it did when it went in, plus the little metal bits. This isn't my filter, but mine doesn't look this bad: I'll try to get pictures of my filter and oil.
 
Messages
128
Location
Roswell, GA
 Originally Posted By: crashnscar
...there was metal in it but no big chunks, just small bits smaller than a grain of sand. Also pulled apart the filter, and there was a little bit in there as well...
You didn't indicate whether or not you had seen the same metallic debris in your oil filter after your rebuild and prior to over revving your engine so I'll go out on a limb and say that what you're probably seeing is flecks of bearing material. To know for sure, have the metal analyized as to content. The most common result of over revving an engine is bent valves and/or holed pistons. Since you had to drive the car 200 miles w/o any oil loss, I'd say that you dodged a major bullet. As for the loss of bearing material, you'll need to keep a watch on how much metal ends up in the filter after each change as well as your oil pressure. My experience with racing small block Chevys has shown that once the main bearing have started to erode, the process is ongoing, and eventually, a bearing is going to spin. The best warning before this happens is a drop in oil pressure as the missing bearing material allows oil to spray out everywhere under pressure thereby lowering the overall system pressure. BTW, most bearing material is non-magnetic except for the steel shell; and if you must put a magnetic in your engine to catch ferrous metal, the best place is the oil sump preferably away from the oil pump pickup.
 

crashnscar

Thread starter
Messages
8
Location
Cali
I bought the engine second hand, so that was my first oil change (after over-revving). After letting the oil drip off the filter element, I actually can't really see much oil in the filter at all. It was mainly in the oil that I poured out of the filter. I have actually run it for 400 miles since that happened. 200 on track and 200 highway. Oil pressure is good.
 
Messages
128
Location
Roswell, GA
 Originally Posted By: crashnscar
...It was mainly in the oil that I poured out of the filter...I have actually run it for 400 miles since that happened. 200 on track and 200 highway...Oil pressure is good.
Did you happen to check with a magnet to see if the metal debris was ferrous? If the majority of the debris was ferrous, the usual sources are rings, bore, springs, lifters, retainers and then rocker arms in that order. Sounds like the rings are fine since you're not buring oil. It wouldn't hurt to remove the valve cover(s) to see if there is any debris lying around underneath. Did any of the debris glitter? This is usually an indication of aluminum in the oil. (Very common in the early 70's as we used aluminum valve spring retainers on our race engines.) Not knowing what type of engine you have, I couldn't say where the aluminum was coming from except all pistons are made of aluminum. Hope this info helps!
 
Messages
277
Location
ohio
why was the engine rebuilt? if it had spun a bearing it has to be cleaned everwhere, all oil passages including the crank,if the crank was reground it must be completelt cleaned, also a oil cooler if you have one. folks make a mistake in not doing all of this when rebuilding a engine and these specs you see may just be leftover. folks who rebuild a engine from a spun bearing who do not completely clean all oil passages usually spin another shortly
 

crashnscar

Thread starter
Messages
8
Location
Cali
It was built to make more power, out of a "stock" motor... one of those classes (Spec Miata). Was also done by a very well known name, so I'm confident it was done correctly. I have talked to someone else who had a motor built by the same guy and he said he had metal in his oil for a few oil changes before it started to go away, I'm assuming that was just normal break in though.
 

crashnscar

Thread starter
Messages
8
Location
Cali
Oh, and I do not believe it is ferrous. Leads me to believe it's bearing material. I guess then the question is: how much is too much? And should I have it gone over by the builder? And will having that done now vs later save me money?
 
Messages
82
Location
Dallas
do you have any coatings in the internals? If this was the first change I would not worry about it, but monitor on the next change. Overreving should not affect bearings...it flings rods, valves, and valvesprings. How good of a prime did you get before cranking the motor?
 

crashnscar

Thread starter
Messages
8
Location
Cali
No coatings. It was not the first oil change either. Why does over-reving not affect bearings? The extra stress from the piston having to change directions more quickly could make the bearings go, I think. Prime? Oil system prime? It's not a brand new motor. It's a 2nd hand rebuild, that had been run multiple times by the previous owner. When I installed it in my car though, I unplugged the ignitor and CAS and turned it over for a while though.
 
Messages
82
Location
Dallas
rev-limit is not set by bearings, its set by valvetrain typically. could this be a '99 motor with thrust-bearing failure?
 
Messages
691
Location
Aridzona
 Originally Posted By: crashnscar
WOAH! That's pricey for a simple magnet....
No kidding. Just buy a half dozen of the mid-sized magnets from here and stick them on the filter. United's magnets are VERY potent.
 
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