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Aug 9, 2023, 08:27 PM
#5536
EvoM Guru
Depends how often you change your oil. Easy enough to crack the filter off and replace it and while your changing over grab a sample. much easier when your drysump and your filter is the high point though haha. wet sump would be a nightmare.
Aug 11, 2023, 05:21 PM
#5540
Typically I would have thought oil starvation would cause lots of damage to the mains bearings too.
Rod bearing damage can be oil related or tune related. Bad fuel, low fuel pressure etc.
Aug 11, 2023, 08:21 PM
#5542
Rod bearings can certainly be hurt if timing is too far advanced but usually all rod bearings will experience damage before any mains when it comes to oil starvation. When I spun #4 rod bearing in my evo years ago the rods showed increasingly worse wear leading up to #4 and none of the mains showed anything concerning. Edit: I went back and looked, my mains did show some signs of starvation the further they went but the rods were much more evident.
Poor fuel or leaning out will typically hurt a piston before a bearing.
If the bearing was being overloaded you would see much more wear on the rod half than the cap half and would also likely see some wear in the girdle side of the main bearings. The 4G fortunately has fairly wide bearings so overload failures are not really an issue until you're in the 1000+ hp range.
Poor fuel or leaning out will typically hurt a piston before a bearing.
If the bearing was being overloaded you would see much more wear on the rod half than the cap half and would also likely see some wear in the girdle side of the main bearings. The 4G fortunately has fairly wide bearings so overload failures are not really an issue until you're in the 1000+ hp range.
Last edited by Ayoustin; Aug 12, 2023 at 12:56 AM.
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ViciousLSD (Aug 11, 2023)
Aug 11, 2023, 10:12 PM
#5543
EvoM Guru
iTrader: (1)
Originally Posted by Ayoustin
Rod bearings can certainly be hurt if timing is too far advanced but usually all rod bearings will experience damage before any mains when it comes to oil starvation. When I spun #4 rod bearing in my evo years ago the rods showed increasingly worse wear leading up to #4 and none of the mains showed anything concerning.
Poor fuel or leaning out will typically hurt a piston before a bearing.
If the bearing was being overloaded you would see much more wear on the rod half than the cap half and would also likely see some wear in the girdle side of the main bearings. The 4G fortunately has fairly wide bearings so overload failures are not really an issue until you're in the 1000+ hp range.
Poor fuel or leaning out will typically hurt a piston before a bearing.
If the bearing was being overloaded you would see much more wear on the rod half than the cap half and would also likely see some wear in the girdle side of the main bearings. The 4G fortunately has fairly wide bearings so overload failures are not really an issue until you're in the 1000+ hp range.
Last edited by LetsGetThisDone; Aug 11, 2023 at 10:17 PM.
Aug 12, 2023, 01:00 AM
#5544
Yea it's all spinning metal, anything starved long enough will wear into each other exceedingly fast. Rods will tend the suffer first, followed by mains. Haven't seen many engines with valvetrain wear from starvation, but it certainly happens.
If the block is going to be reused make sure you pull all of the gallery plugs and clean it thoroughly, getting put through a jet washer and even an ultrasonic is not enough to get all of the contamination out.
If the block is going to be reused make sure you pull all of the gallery plugs and clean it thoroughly, getting put through a jet washer and even an ultrasonic is not enough to get all of the contamination out.
Aug 12, 2023, 01:47 AM
#5545
EvoM Guru
iTrader: (1)
Originally Posted by Ayoustin
Yea it's all spinning metal, anything starved long enough will wear into each other exceedingly fast. Rods will tend the suffer first, followed by mains. Haven't seen many engines with valvetrain wear from starvation, but it certainly happens.
If the block is going to be reused make sure you pull all of the gallery plugs and clean it thoroughly, getting put through a jet washer and even an ultrasonic is not enough to get all of the contamination out.
If the block is going to be reused make sure you pull all of the gallery plugs and clean it thoroughly, getting put through a jet washer and even an ultrasonic is not enough to get all of the contamination out.
This crank obviously won't be reused, but we also remove the ball bearings from the crankshafts oil passages for proper cleaning, and drill/tap the crank for thread plugs and install before balancing.
The machine shop I use... their main line of work is building turn key/drop in trophy truck engines that cost $100k.
Aug 12, 2023, 08:41 AM
#5546
Pulling all the plugs and hand cleaning with bottle brushes is SOP regardless of the engine having failed
This crank obviously won't be reused, but we also remove the ball bearings from the crankshafts oil passages for proper cleaning, and drill/tap the crank for thread plugs and install before balancing.
The machine shop I use... their main line of work is building turn key/drop in trophy truck engines that cost $100k.
This crank obviously won't be reused, but we also remove the ball bearings from the crankshafts oil passages for proper cleaning, and drill/tap the crank for thread plugs and install before balancing.
The machine shop I use... their main line of work is building turn key/drop in trophy truck engines that cost $100k.
Aug 12, 2023, 12:21 PM
#5547
EvoM Guru
iTrader: (1)
Originally Posted by Ayoustin
I should've been more specific, that part about cleaning wasn't directed at you haha. I know you know what you're doing
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Aug 12, 2023, 04:33 PM
#5550
Purple/blue dots are 63-70 degC (145 to 158 degF) on this setup is around 72psi at the mains gallery (approx 82-85 at the oil filter housing).
If the rpm increased at that temp, we would see around 85-90psi a the mains gallery.
"At 80ºC oil temperature (176ºF) and 5500-6000rpm, a reasonable oil pressure number is 90-100psi when measured at the oil filter housing. Measuring oil pressure in the mains gallery (in the OEM oil pressure switch location on Evo 8) will be 10-12psi lower than the oil filter housing."
[section from the IE instructions]
The reason why I say to go to 5500-6000rpm to check the oil pressure when it's hot (80 degC) is that will be around your maximum oil pressure.
If you're 100psi at 3500rpm, then you're probably 120psi (approx) above 5000rpm. Oil grade/weight and oil temp dependant.
While this isn't a "problem", it's probably a bit high. I recommend 90-100psi at the oil filter housing when at operating temp.
That being said, the high oil pressure shouldn't cause any problems. But you will need to keep an eye on the cold oil pressures, they may be far too high (150++)
The following 2 users liked this post by RSMike:
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