1BIGJIM

Like I mentioned I tried the "I cleaned it out" the oil cooler and it lasted about 10 hours. After the second spun bearing I even put all new hoses on my new oil cooler.
I even cut open the oil cooler and you could see little pieces of metal smiling back at you

My 496 is in a 22' Pachanga so it scoots right along
I just put some new Edelbrock heads on it and am waiting to launch next week.

articfriends

Oil coolers trap metal,for all the aggravation your going thru throw it in the trash and buy a matching one to your other aftermarket one.Are you tearing motor COMPLETELY down each time and cleaning every nook and cranny,oil passage etc? New oil pump too,once the metal starts to circulate it gets EVERY where.I always clean block myself even after machine shop has cleaned it just in case they missed something,rinse then blow out all your oil passages etc. Keep us posted,Smitty

formula31

Just a note. On a Mark 4, the oil goes out the side of the adaptor at a slight angle (kinda like the same angle as a sparkplug), then up to the filter, then down to the front of the cooler and out the cooler and back in the front of the adaptor. I think you said the same thing but it sounded backwards. Just wanted to make sure you understood the path. Oil goes in the outside of the filter and out from the inside.

I would also mic that journal and make sure the grinder didnt miss it or its off size or something wierd.

BillK

fhb,
No body else has asked, so ..... how was the engine repaired each time ? A spun bearing requires that the crankshaft be reground and the connecting rod be resized (if possible) or replaced. Was this done after each failure or did you just replace the bearing and try again ? Also, the entire engine needs to be disassembled and all of the oil passages thoroughly cleaned.
Also, I think an item that is overlooked by many with this type of problem is the condition of the piston pin. If it is too tight and the piston cannot freely move on it, it affects the loads on the bearing and can cause a failure.
Personally, I doubt that it is an oiling problem due to the fact that the failure is on the back bearings which are closest to the oil pump. Usually (but I guess not always) an oil system problem shows up near the front of the engine as that is the farthest from the oil pump.
There may be a one in a thousand exception to my first statement, but I have yet to see a spun bearing that did not damage the crankshaft and certainly the rod.

Hope this helps,

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

fbh-velocity

From first rebuild to last rebuild the engine was totally disassemble, all oil channels in the block was high pressure hot water/steam wash.
Brand new lifters each time to make sure they don't hold any particle.
First rebuild was with reground stock cast GM crankshaft .010 the next was with brand new Eagle steel crank from Summit, with matching bearings.
New oil pump each time, but only standard volume, even tjek out the clearance in oil pump to be sure, and new rods. All work is very carefully inspected and done by the book.

If it is so, that the oil goes direct to filter before oil cooler (as Formula31 describe) I would guess the filter would take most of the metal particles before it went to oil cooler.? Anyway I don't want to use the old oil cooler anymore.

Any other ideas ?

1BIGJIM

'block was high pressure hot water/steam wash'
You should use brushes in the oil galleys and hot tank it at least two times. Metal gets everywhere when you spin a bearing. I even had even seen it take out the valve guides.

KAAMASCARAB

To clean my blocks i cut the loops off the end of a long oil galley brush and chuck it in a drill. go over all passages many times. use Power Clean or eq. as the soap. check bearing clearences w/a dial bore gauge- should be @..0018-.0023". check roundness of crank journels and bore of rod. make sure you have enough bearing crush so it doesn't spin.

mopower

Stupid suggestion but a definite possibility...oil lines to the filter are backwards and you're using an oil filter with an anti drainback valve. This will restrict the flow of oil severely while still showing good pressue on the guage.

Just a thought since everything else seems to have been covered.

Raylar

I know that sometimes you guys think you are really saving a lot of money and having more fun doing your own motors, but WTF. With stories like this you are costing yourself more money in the long run, frustrating the chit out of yourself and in some cases missing good boating time and making boating very unfun. Would you do brain surgery on your own kids, even if you could rent the operating room or buy the scalpels drills and plasma. Hell no! Unless you are really a qualified engine builder with years of proven results, just save yourself this kind of grief and money, hire a good professional in the industry and spend your time enjoying boating!! Just my years of expierence speaking here.

Ray @ Raylar

Strip Poker 388

Ray

I don't think I have done to bad not being a engine builder I am sure a real engine builder could of made more power with close to the same parts that I used. But I am proud of what I have done so far.

Even if nobody will stand next to my motors on the Dyno while there running and they tell me I have to clean up the mess if my motor grenades

It does sound like he needs some help.Wouldn't if the oil line were routed wrong it would show up on the gage?

Rob