Metal flakes in the oil filter..
#1
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jul 2010
Location: Seattle Area
Posts: 74
Total Cats: 0
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
What's this stuff?
Looks like thin flakes. It sticks to a magnet but not like steel, comes off the magnet a lot easier than steel shavings.
So not aluminum, not steel. Could it be bearing material (some alloy containing some steel)?
I rebuilt the engine 1000 miles ago, just rings, bearings and forged rods.
A small radiator leak lead to a blown head gasket. I took this as excuse to install forged rods (SGI forged H-beam)
to get ready from moar boost.
The block needed to be decked because the surface was pretty pitted.
All the wear tolerances (bearings, end play, ring gap, oil pump clearance, etc) were about halfway between min and max after 160K miles, 11K of which with 8-14 psi from a 2554r. The oil pump relief piston and spring were worn so I replaced those.
Looks like thin flakes. It sticks to a magnet but not like steel, comes off the magnet a lot easier than steel shavings.
So not aluminum, not steel. Could it be bearing material (some alloy containing some steel)?
I rebuilt the engine 1000 miles ago, just rings, bearings and forged rods.
A small radiator leak lead to a blown head gasket. I took this as excuse to install forged rods (SGI forged H-beam)
![Drool](https://www.miataturbo.net/images/smilies/drooling.gif)
The block needed to be decked because the surface was pretty pitted.
All the wear tolerances (bearings, end play, ring gap, oil pump clearance, etc) were about halfway between min and max after 160K miles, 11K of which with 8-14 psi from a 2554r. The oil pump relief piston and spring were worn so I replaced those.
#5
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jul 2010
Location: Seattle Area
Posts: 74
Total Cats: 0
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Yes, I had the crank polished.
I checked the oil pump for clearances, all within spec. The pressure relief piston had some scoring (the bore looked fine) so I repleaced it.
The Spring was worn (free length was under spec'ed minimum) so I replaced it too.
I guess it's time to pull the engine (again) and see what's going on.
Has anyne around here used Toga Race bearings?
They have a groove in both bearing caps, not just the upper.
Gunter
I checked the oil pump for clearances, all within spec. The pressure relief piston had some scoring (the bore looked fine) so I repleaced it.
The Spring was worn (free length was under spec'ed minimum) so I replaced it too.
I guess it's time to pull the engine (again) and see what's going on.
Has anyne around here used Toga Race bearings?
They have a groove in both bearing caps, not just the upper.
Gunter
#8
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The oil pump could very well have been a rockstar when the damage occurred, but all those little metal shavings in your oil filter had to travel through your oil pump to get there, this is why I suggest inspecting the pump - you wouldn't want a future stuck pressure relief valve causing you to have to do *yet another* teardown/rebuild. /rainbowbarf.jpg
#10
Former Vendor
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,100
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Do not run the motor any further. If you pull it now, the repairs will cost you about 30% of what they will cost you if a bearing fails.
IMO, I would not reuse the oil pump from that motor under any circumstances.
IMO, I would not reuse the oil pump from that motor under any circumstances.
#13
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jul 2010
Location: Seattle Area
Posts: 74
Total Cats: 0
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The #2 rod bearing is toast..
I posted hi-res pics of all the bearings at:
https://skydrive.live.com/redir.aspx...ive&Bsrc=Share
The strange thing is that the neighboring main bearings are OK and the oil passage in the crank is not obstructed. No idea what destroyed the bearing.
Any theories?
The rods are SGI forged H-beam (there ar some threads on these).
The bearings are ACL, std size.
The cleanup is going to be tedious, metal flakes everywhere...
I posted hi-res pics of all the bearings at:
https://skydrive.live.com/redir.aspx...ive&Bsrc=Share
The strange thing is that the neighboring main bearings are OK and the oil passage in the crank is not obstructed. No idea what destroyed the bearing.
Any theories?
The rods are SGI forged H-beam (there ar some threads on these).
The bearings are ACL, std size.
The cleanup is going to be tedious, metal flakes everywhere...
#17
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jul 2010
Location: Seattle Area
Posts: 74
Total Cats: 0
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I installed the bearings in the rods and torqued them then went to the shop that did the machining and had him mike the rods and crank for clearance, it checked out OK (0.0019 - 21).
After I put the bottom end back together (with plenty of assembly lube) , I installed the head. Before I put the cam shafts back in, I primed the oil pump by pouring down oil to the oil pump through the oil filter opening. Then I used a beefy drill to spin the crank until oil came out of the bores that lubricate the cam shafts to make sure that there are no obstructions. After installing the cams, and the rest of the top end, I hooked up the oil pressure sender and spun the crank again using the drill for another couple of minutes, oil pressure was around 40 PSI, not sure what the revs were somewhere around 600 - 700 RPMs. After putting the engine back in the car, I fired it up and let it idle until it reached normal operating temp (oil temp around 180F).
After that, I shut it off, let it cool down and change the oil filter. I cut open the oil filter I took off, it was clean.
As for break in, I unhooked the waste gate for the first 50 miles or so and did lots of accelerate/overrun cycles to seat the rings. Then I hooked up the waste gate again and took it easy for the next 200 miles or so (that was the hardest part...), still doing accelerate/overrun cycles. The next 750 miles, I drove it normally, avoiding super-high RPMs. After 1000 miles, I drained the mineral break-in oil and thats when I found the flakes in the filter.
After I put the bottom end back together (with plenty of assembly lube) , I installed the head. Before I put the cam shafts back in, I primed the oil pump by pouring down oil to the oil pump through the oil filter opening. Then I used a beefy drill to spin the crank until oil came out of the bores that lubricate the cam shafts to make sure that there are no obstructions. After installing the cams, and the rest of the top end, I hooked up the oil pressure sender and spun the crank again using the drill for another couple of minutes, oil pressure was around 40 PSI, not sure what the revs were somewhere around 600 - 700 RPMs. After putting the engine back in the car, I fired it up and let it idle until it reached normal operating temp (oil temp around 180F).
After that, I shut it off, let it cool down and change the oil filter. I cut open the oil filter I took off, it was clean.
As for break in, I unhooked the waste gate for the first 50 miles or so and did lots of accelerate/overrun cycles to seat the rings. Then I hooked up the waste gate again and took it easy for the next 200 miles or so (that was the hardest part...), still doing accelerate/overrun cycles. The next 750 miles, I drove it normally, avoiding super-high RPMs. After 1000 miles, I drained the mineral break-in oil and thats when I found the flakes in the filter.