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Metal in Heads..Where Could It Be From?
I found tiny brite shinny metal bits in oil filter. They are iron based since magnet attracts them. Pulled the valve covers and found the same in the low spots of pooled oil. I inspected the roller rockers and the valve stem tips. These look in perfect condition.... I mean perfect. I expected to see some spalling of the valve stem tips or rocker rollers but not. I have not yet inspected the springs and retainers. What other source could deposit this metal in the head area?
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Camshaft ??
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could use more information on engine like what camshaft,what valve springs and what material the retainers are made from.also do they have aftermarket valve seals.
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It is a Mercruiser 496 that has little left that is stock other than block and accessories. Valve springs are PAC 1295x beehive and PAC steel retainers. Cam is custom mfg by Cammotion. Trend push rods, JE forged pistons, TotalSeal gapless rings, Crane aluminum exhaust and scorpion aluminum intake roller rockers, Melling high volume oil pump, Ferrea super alloy valves, stock Mercruiser lifters, Scat forged stroker crank, brass valve guides, Clevite bearings, forged Scat H rods, Comp Cam Viton valve stem seals.
Basically just want to know what/where ferrus metal can come from that can get onto top of heads. |
Almost all of the internal parts of that engine, excluding bearings, pistons, valves and guides, and maybe the distributor gear are ferrous (magnetic). i would look or use a magnet in the discharge passage of the oil filter and see if it’s there, then work my way through the oiling system until it starts showing up. If that doesn’t work... which it probably won’t, I would check the cam drive and distributor, then the lifters/cam. oil pump is unlikely since it’s under the valve covers is this a new build, how many hours running? |
i had one apart that had the springs in the valve seals brake,looks like small shiny junk in the pan and short little parts laying in the heads.these were hp500s with dart aluminum heads and a big hyd roller cam.they were just plain tired engines.
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Originally Posted by mike tkach
(Post 4655126)
i had one apart that had the springs in the valve seals brake,looks like small shiny junk in the pan and short little parts laying in the heads.these were hp500s with dart aluminum heads and a big hyd roller cam.they were just plain tired engines.
90 hours on rebuilt engine. I understand what all is ferrus and what can wear. That is not my question. My question is only what ferrus components when they wear or fail their debris can physically show up on the top of the heads? |
Follow the oil... lifters-pushrods-rockers-valves-retainers/springs/guides. Make sure your push rod guides are not wearing.
I would pull some rockers and pushrods, take a good look at everything, if you don’t find anything then pull the intake and look at the lifters. i have seen so many failures where metal gets to places you would never believe so there’s that too... |
Valve spring shims, especially if they didn’t use hardened shims at the top of the stack |
I'd pull it as much of a pain it might seem. Inspect everything to get to the root of the problem and you'll sleep better. |
Comp Cam |
any oil pressure issues ?
inspection of the roller rockers ? compression solid I know your not a stock app so asking about the inner spring / valve springs ?? |
Merc stock lifters - I would take a look at these under close inspection
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Originally Posted by AllDodge
(Post 4655266)
Have a lot of high quality parts in the motor, but from what I have read here, Comp is not the cam you want
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Originally Posted by BUP
(Post 4655270)
He reports the cam is from cam motion -- they are in Louisiana
See post 4 mentions both Sorry, my bad, still think Griff has the answer |
Thanks to all for taking the time to share your thoughts. I found the culprit. I knew that the PAC beehive valve springs rotate above a certain rpm. The spring rotation speed increases as rpm increases. In past inspections I noticed a light polish where the spring contacts the retainer. This time I found scoring on most of the retainers from that spring contact/rotation. That is where the metal came from. I will be talking to PAC about this.
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Originally Posted by Rage
(Post 4655311)
Thanks to all for taking the time to share your thoughts. I found the culprit. I knew that the PAC beehive valve springs rotate above a certain rpm.
Just curious |
Originally Posted by Rookie
(Post 4655320)
Why are you running beehive springs?
Just curious I ordered tool steel retainers to replace the chrome moly retainers that were producing the metal. |
https://cimg2.ibsrv.net/gimg/www.off...bab6f63e57.jpg
https://cimg7.ibsrv.net/gimg/www.off...06f49ca2b5.jpg I had the same issue. Turned out, the shop that put the heads together, didnt use the correct hardware, for the springs. The locator shoulder measured like .680, and the inner springs ID measured like .740 if I recall. The retainer fit also wasnt the best. The springs were rotating, and digging into the locators, leaving tiny metal specks in the heads where the oil pools. Also, the inner spring was rubbing on the stem seal, likely from the pizz poor setup. Springs had good pressures, around 180/470 when tested, but were the wrong springs. They were a mile away from coil bind. Probably surging, wobbling, and dancing all over the place. Lesson learned with that shop. |
Thanks for sharing that. Identical condition to my retainers. PAC recommendation for 0.080" coil bind clearance was followed. The beehive allegedly has some inherent surge damping because of its range of spring coil diameter and spacing. Did you see any evidence on valve stem tips or rocker arm rollers that indicated valve train instability?
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No signs of valve float or anything
How tight of a fit are your aprings to the locators/cup and retainers ? |
Originally Posted by MILD THUNDER
(Post 4655494)
https://cimg2.ibsrv.net/gimg/www.off...bab6f63e57.jpg
https://cimg7.ibsrv.net/gimg/www.off...06f49ca2b5.jpg I had the same issue. Turned out, the shop that put the heads together, didnt use the correct hardware, for the springs. The locator shoulder measured like .680, and the inner springs ID measured like .740 if I recall. The retainer fit also wasnt the best. The springs were rotating, and digging into the locators, leaving tiny metal specks in the heads where the oil pools. Also, the inner spring was rubbing on the stem seal, likely from the pizz poor setup. Springs had good pressures, around 180/470 when tested, but were the wrong springs. They were a mile away from coil bind. Probably surging, wobbling, and dancing all over the place. Lesson learned with that shop. i had had a very similar situation after a few dyno pulls and not happy with the numbers I just jumped the gun and changed over to solid lifters and went to heavier springs. I'd normally swap out my self however just sent parts to shop for quick installation so I could come back down for some more pulls and tuning. I wanted to check seat and open pressures to be certain they were what Valako wanted for the custom grinds. Low and behold I discovered the shop assembled new springs and used the same locators and retainers. About .050 of spring side to side motion. At least it was caught and resulted huge gains as the springs were spec'd wrong to begin with and hyd rollers were bouncing all over place. The lobes were a little on the aggressive side that didn't help matters. |
What valve spring OD vs Spring cup ID clearance do you shoot for?
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I had a cam thrust washer crack and shave enough metal off the block it never went further then the first firing. Another $1800 to rebuild again.
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