ctuck0659

Long story of course but here's a summary: I had a very reputable performance engine builder rebuild my 502 rotating assemblies into 540's with Scat 1-42500 kits in 2013. He of course tanked the engines, spec'ed all the clearances, line-bored the cranks etc. Installed high flow oil pumps. All bearings and every internal engine part that moves was replaced. This is not a case of shortcuts taken or a shabby rebuild so please don't go there. . Originally used the stock remote oil lines, filter housing and cooler. After break-in switched to synthetic 20W-50 and started noticing oil temp went to 300+ deg after a hard run. Immediately swapped stock coolers to Revolution 3.5X18" coolers and oil temps normally ran 220 deg, never went above 260. This past summer I started noticing some loss in oil pressure so I did some research and swapped out the 3/8" oil lines for 12-AN. About a month after that both engines started to increasingly lose more oil pressure when hot. By the end of the summer the pressure dropped to less than 10 lbs at idle when hot so I pulled the engines and not surprisingly found severe bearing damage consistent with oil starvation. So the obvious conclusion might be that running the small stock diameter oil lines restricted the flow and is the cause of the bearing failure at less than 100 hrs. EXCEPT: how do you explain that the bypass valves in the block oil filter mount should have opened and shunted the oil directly back into the motors when the pressure differential got too high in the lines?? I change my oil approximately every 20-25 hours so there's no way there should have been enough normal combustion byproduct garbage in the unfiltered oil to trash the bearings after 90 hours. If the smaller oil lines are the culprit that's my fault and I can live with that, but I can't see how that was the cause given the fact that the bypass valves are engineered into these engines for that very reason. What I can't live with is not understanding what happened so I can make sure I don't make the same mistake again. Any thoughts or insights are appreciated-

sutphen 30

damage to the bearings happened when it hit 300°,,after that,,it just was a matter of time.hi flow pump,small lines,,recipe for disaster.

BenPerfected

Who made the recommendation to use the 3/8" oil lines?

14 apache

iTrader: (1)

A friend has about ten hours on his engines had about 10+ft of -8 oil line and hot oil went threw the cooler than to the oil filter. This motor was running by passing oil filter trashed the bearings. Btw 300degrees will start to take bearings apart. And bypass oil filter it will die soon.

blue thunder

I'm guessing he meant 5/8" not 3/8" stock oil lines. Regardless, too high an oil temp is clearances too tight, lean, too much timing or cooling issue of some sort.

BT

dunnitagain

Were the Oil Filters Plumbed properly? Any and All filters flow from the Outside, In, Smoked the rotating Assy out of a Ford Sprintcar Engine 3 times , because the Oil Filter was plumbed backwards. The 300* oil didnt help , but it wont kill the bearings.

14 apache

iTrader: (1)

Upgrade your membership so you can post pictures or it's to difficult to diagnose all your problems.

getrdunn

iTrader: (7)

Sometimes with so many lines, coolers, t-stats etc it is not out of the question to have that happen. I know it sounds ignorant but it's real world chit that can happen. I plumbed an engine with this that and the other thing and before installing filer I actually primed slowly just to make certain was A-OK. 300 deg for a very short period and mobile 1 for sure pushing limits but have heard of worse.

I like to keep oil temp gauge right next to pressure gauge. When I see engines with no temp gauges it makes me cringe.

f_inscreenname

I'll join you on that mistake but I only did it once.

getrdunn

iTrader: (7)

Find out what bearings rookie used for your next time around also. He posted a pic of severely thrashed on engines and bearings looked perfect. Also as mentioned your lines are more than likely 5/8. Don't get down on yourself to much even though it sucks. It's how you handle it moving forward. Cooler and hose size and best oil you can buy. Also bearing clearance. What kind of water temps you running in? Stock 365 mag coolers in lake mi on a 500 hp engine I'd never see more than 250 even on the hardest running days.