Piston pin bad ?

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Not sure what happened to the rockers since I was hyper vigilant about assembly , oil priming and checking supply of oil to rockers. Yes I installed the shafts properly...also rotated engine while priming ( I primed the heck out of it.) so much that I started to worry about the oil washing the breakin lube off cam.

The thing is that I had to return the first pair of shafts to Hughes because they ballooned when I installed the oil plugs in the ends and I could not get the rockers off the ends of the shaft.
 
Hughes should warranty all that stuff but I doubt they will. You obviously had problems. I guess their new Vendor that makes their rockers has quality control on the bottom of their list.
 
SGBARRACUDA said:
Did the Rockers seize to the shafts? Are they galled up?
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oh yeah ....I havent pulled the drivers bank yet but all the pass. side ones are galled to a point... the #8s will barely move !

I will call Hughes in the morning .

The clearance between the shafts and the rockers were super tight.
I thought it was pretty impressive at the time , but now that I think about it I am not sure that is a good thing... Aluminum and hardened steel expand and contract at different rates...right?
 
Be prepared - this will all be your fault as the assembler. I'd look into a new set of rockers and that one piston. I agree - it's bits of piston that came off & went through and then out the exhaust.
 
Yes you are right, aluminum and steel expand and contract at different rates. I will be also listening to how Hughes handles this. Harland Sharp, Jesel and T&D cost more but as my dad use to tell me, "SON, NEVER BE AFRAID TO BUY THE BEST, YOU WON'T BE DISAPPOINTED!" I have ran Harland Sharp in all my race/street engines without a single failure
 
Absolutely. AL around a steel shaft will loosen when heated. AL has a thermal expansion coefficiant of 12.3 while steel is a 7.3. If it fits when cold, it will fit when heated, a tad looser at that.rarely will you find a steel around an AL shaft, pistons excluded byt they have built in safeguards.
 
SGBARRACUDA said:
Forgive me for throwing this out there if I'm wrong. But this looks like water corrosion on the tops. You said this engine was built many years ago? Looks like moisture got in the engine and caused the pitting? I really don't think it has anything to do with your noise.
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JIMO, I am still thinking the same thing as above. With moisture, the piston top would corrode, oxidize, and it would look like the piston top shown with pits all over, and most of it would just vaporize with a little bit of combustion. It looks like a few bits of AL on the valve faces. I can't see anything hitting on the head's combusiton chamber surface; looks like a normal cast surface. AM I missing something in that pix?
 
nm9stheham said:
JIMO, I am still thinking the same thing as above. With moisture, the piston top would corrode, oxidize, and it would look like the piston top shown with pits all over, and most of it would just vaporize with a little bit of combustion. It looks like a few bits of AL on the valve faces. I can't see anything hitting on the head's combusiton chamber surface; looks like a normal cast surface. AM I missing something in that pix?
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This was my thought, but it is hard to tell in a picture. If I had it in my hand I might think other wise?
 
^^^ Yep, just going by appearances.

I admit the beer can had me going for a minute.....I'll bet it has happended!
 
At this point I am not to concerned about the piston. It will have to be replaced and the block and rotating assembly checked out and cleaned up. The water thing makes sense except for the fact that there should have been signs of that much water in exhaust .
Are you thinking water was sitting in cylinder during storage? Not possible since when I
Assembled the top end all holes were shiny and clean.

I am about to pull drivers rockers off.... If they are toast I am suspecting defect in materials...
 
I would also check the ring clearance on the piston, the top gap on the KB pistons should be around .030.
 
Driverside rockers were not binding but the shafts were wearing.

This cant be normal after 45-60 minutes of run time. 20 of that driving slowly to shop for alignment and exhaust work.. The spring perches are not welded up yet so I had to drive real gentle.
 

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Oil was running out of both shafts when I picked them up.
Wear marks are on the slot side so we know i didnt install them upside down.
 

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Your right about to much wear. Were the rockers,springs,push rods covered in oil when you removed the valve covers? In other words did it look like plenty of oil was getting to the top of the engine?
 
Plenty of oil. Puddles in valleys of head.Oil poured out of shafts when I picked them up .
Grooves to the bottom as evident by the location of wear marks!

I wonder if the clearance of the rockers on the shafts was just to tight ? But if aluminum expands more than the shafts I wouldnt think that would be the case...of course they would have to get hot first and that could take a while .
 
This all speculation so far. But I really cant figure out what went wrong ?
I always try to buy new parts on critical components just so I dont have issues and because I have the chance of recourse in the event that there is a problem. I hope....
 
I'd like to see more pix of the damaged piston, the skirts, ring gap in relation to failure, any signs of piston/valve interference, and of the spark plug.. also the tops of the valves... pls/thnx

you're absolutely right,, you have to find the root cause..
 
Going to pull short block on sunday and take it to machinest. Will take pics of piston then.
When you say tops of valves do you mean stem caps?
Even if gaps are off and skirts are shot how does that explain all shafts and rockers being galled after 40 minutes ?
 
I have more questions than answers myself..

I agree the piston looks like it had water on it, it would take a large quantity of fluid to cover the entire piston on a V8, and were it condensation from aspirating thru an open valve, for 6 yrs, I feel the condensation would accumulate at the bottom of the piston,, not evenly coated across the surface..

At this point we need more info,, or as you said it's speculation..

As for the rockers shafts,, they may be a completely diff issue unless they held a valve open that contacted the piston, causing the damage, yada yada.. lol

The skirts would perhaps indicate if detonation was taking place,, and I have seen detonation on a single piston.. If it was detonation, the heat and pressure is astounding, and could cause the piston/ring failure, that broke the piston yada yada that Jack built.. lol

hope it helps

PS ..can someone give me an opinion on the ex. seat post 87, I think.. Might just be my eyes again..
 
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