roscobbc

Like the expression "Ghost Noise" - sure sounds spooky to me!

roscobbc

Well guys - I've finally pulled the oil pan and following initial inspection found that no.1 big end is well an truly ****ed! - with 20 to 30 thou' play removal of no.1 and no.2 caps followed.........didn't expect this
No.1 & 2 journal

No.1 cap and complete shell







No. 2 cap

No. 2 cap & shells

427Hotrod

OUCH, Hate to see that. You're in for a complete teardown and cleanup, It will be interesting to see what the mains look like. The front two can be starved pretty easily. The long stroke motors are really picky about oil pans and windage. Very easy to get air in the system which doesn't lube very well. Which pan do you have? High oil pressure isn't an issue....I've run a lot for years...but it has to be solid with no dips. Same as if you had lower pressure.

JIM

roscobbc

Hi Jim - pan is stock type - stock capacity - no windage tray/screen, just a small baffle in bottom of pan. Was considering bigger capacity pan and windage tray when doing re-build (for the very reasons you mention). Been suffering from 'manflu' and a backache for a few days - so will get under the car and take some closer images of rods etc. in a day or so........... look after yourself.......

427Hotrod

Thanks...I'm doing well.

Might as well start pulling it out. Not much more to do at this point. Good news is cranks aren't mega priced and/or you can fix that one. Is that a steel or cast one? Internal or external balanced?

We need a real good pan on anything over 4" stroke for sure. That front section of the stock style pan is just too close to the rotating parts to allow oil to get away from it. Causes foaming and windage issues.

JIM

JIM

roscobbc

Supposed to be forged crank - and internally balanced - and yes, 4.25" stroke.

427Hotrod

Should be able to turn it on either just the rods or mains also depending on how they look. Won't affect balance.

You can rebuild the rods or just buy two more, Need to look for signs of detonation on the rest of the bearings (uppers on rods and lowers on mains),

Past that it's just clean clean clean....everything. Ck pistons for metal embedded in the skirts and spend a lot of time with a pressure washer flushing the galleys.

JIM

cardo0

Post #1 said u had high oil press with 70# at idle and off scale at cruise. I would think worn bearings would reduce oil press as the sys has less backpress around the bearing - someone correct here. Maybe u need to look at your oil press gauge calibration. Or maybe oil flow was too fast to maintain the oil film barrier - i can only guess that.

Sorry to read the news.

427Hotrod

My gut tells me there's some plugged oil holes with bearing material. When the bearings spun and stacked up some the clearances got real tight and pressure will rise. There might be more damaged ones as it's torn down. Could be metal stuck in bypass of oil pump also.

The high oil pressure isn't an issue. There may be some gauge issues but there certainly isn't a problem with high pressure wiping bearings or moving too fast. FE Fords, Buicks and Olds HI Perf engines have used over 100 psi for years to deal with the bearing speeds and they work fine.

BBC and SBC can certainly live with less pressure....they have a good system.....but 70-80+PSI at high RPM isn't a problem.

JIM

roscobbc

What would I do without you guys eh? -
Jim - on a previous post you said "Should be able to turn it on either just the rods or mains also depending on how they look. Won't affect balance". - I wasn't too sure what you meant there?

427Hotrod

I meant that you can "turn" the crank undersize (machine it) to say .010" or .020" undersized pretty easily and it won't require you to rebalance it. As long as crank hasn't been turned too blue from heat it should machine just fine. If a main bearing turns out to look the same it will likely be bent and will either need straightening (good shops do it all the time- it's crude to watch...but it works!), If it's too much it will be time to look into a new crank.

JIM

roscobbc

Thanks Jim - I'm 'with' you now!

cardo0

Looking at my 1988 Chevy Power catalog - 6th edition - i found it saying that the most of engine bearing failures were a result of oil press loss due to the oil pump picking up air while in turns. At racing speeds of course. And is aggravated by:
-insufficient oil level capacity
-high oil flow rates from excessive bearing clearance or unnecessarily high oil press
-poor oil baffling
Just FYI. Or maybe i ate too much chocolate and can justify it by sharing your anxiety.

Again sorry to read the damage. Hoping u can correct the cause of the problem.

roscobbc

I will measure oil pump pick-up position relative to bottom of oil pan. Will certainly look at a larger capacity pan and possible windage tray when do re-build.