Spun Bearing in LT4...what to do?
06-23-2005, 01:09 AM
#21
Le Mans Master
Member Since: Apr 2000
Location: DrunkDefender
Posts: 5,589
Likes: 0
Received 0 Likes
on
0 Posts
CI 1-2-3-4-5-6-7-8 Veteran
CI-IV AutoX Champ
CI-IV Burnout Champ
St. Jude Donor '07-'10
I allways overfill mine during track events and autox also. No problems so far with 80k on the clock. The LT4 seems to suffer from oil starvation a bit more than the LT1 and even more so than the L98 due to its higher redline. The extra rpms keep more oil up top instead of in the pan. Some of the old pontiacs had the same problems in the late 60s early 70s with oil not draining back down fast enough when the revs were high for extended periods.
06-23-2005, 03:00 AM
#23
Safety Car
I have 5000 track miles on my LT4. most of them with an extra qt of oil. guess I've been lucky so far......
what is the actual cause of this #8?
Is it losing oil pressure under braking, or in high G turns ??
what is the actual cause of this #8?
Is it losing oil pressure under braking, or in high G turns ??
06-23-2005, 08:11 AM
#24
Melting Slicks
I spun a bearing in January of last year at Sebring. My 92 had 64K on the clock and probably 3k miles of that on the track. I opted for number 3 and wish I hadn't. Unlike most here, I am unable to do the work myself, and I chose the wrong person to do the work the first time. I now have close to $9k in labor alone and it is still having a few issues.
If you can do the work yourself I say go option 3, but otherwise do the minimum to get you back on the track.
Mike
If you can do the work yourself I say go option 3, but otherwise do the minimum to get you back on the track.
Mike
06-23-2005, 08:28 AM
#25
Melting Slicks
FWIW, I took the hypertech programmer, and I LOWERED the redline to 6000. after reading this, I may lower the redline to 5500.
The hypertech offers a wide range of red lines, and I only use it for that, and the fan temps.
The hypertech offers a wide range of red lines, and I only use it for that, and the fan temps.
The following users liked this post:
louie 94 (02-12-2022)
06-23-2005, 08:37 AM
#27
Safety Car
Originally Posted by the blur
FWIW, I took the hypertech programmer, and I LOWERED the redline to 6000. after reading this, I may lower the redline to 5500..
1) Lack of oil returning to pan during high rpms
2) G-forces during braking....or cornering......or acceleration
3)too high rpm leading to too high forces on bearings
4)too much force on bearings even at lower rpms due to engine mods with increased torque.....
ALL of the above.......others
Limiting rpm's only addresses some of the above????? Is it enough????
06-23-2005, 09:47 AM
#28
Safety Car
Thread Starter
Member Since: Jun 2004
Location: lafayette co
Posts: 4,197
Likes: 0
Received 0 Likes
on
0 Posts
06-23-2005, 04:12 PM
#31
Safety Car
Originally Posted by LT4BUD
I am not sure I understand what leads to spun bearings....
1) Lack of oil returning to pan during high rpms
2) G-forces during braking....or cornering......or acceleration
3)too high rpm leading to too high forces on bearings
4)too much force on bearings even at lower rpms due to engine mods with increased torque.....
ALL of the above.......others
Limiting rpm's only addresses some of the above????? Is it enough????
1) Lack of oil returning to pan during high rpms
2) G-forces during braking....or cornering......or acceleration
3)too high rpm leading to too high forces on bearings
4)too much force on bearings even at lower rpms due to engine mods with increased torque.....
ALL of the above.......others
Limiting rpm's only addresses some of the above????? Is it enough????
How much extra oil is too much? I was afraid to do the 1 qt over thing. I just filled to the top of the recommended line.
06-23-2005, 04:15 PM
#32
Safety Car
Thread Starter
Member Since: Jun 2004
Location: lafayette co
Posts: 4,197
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by sothpaw2
I really want to know the answer to this. I had my LT1 out on the track 3 times now and I always keep the rpms down below 5k unless on a straight (and then 6 k only instantaneously as in drag racing).
How much extra oil is too much? I was afraid to do the 1 qt over thing. I just filled to the top of the recommended line.
How much extra oil is too much? I was afraid to do the 1 qt over thing. I just filled to the top of the recommended line.
I was hanging corners in 2nd, at about 5500 RPM.
The other thing is, do you just burn that much while out there. How do you get it back out?
06-23-2005, 06:01 PM
#33
I would have the motor pulled and have it gone through, if you try to go the cheap route now, it could cost you a lot more in the future if you were to end up ruining the block with a major failure.
06-24-2005, 12:42 AM
#34
Le Mans Master
Member Since: Apr 2000
Location: DrunkDefender
Posts: 5,589
Likes: 0
Received 0 Likes
on
0 Posts
CI 1-2-3-4-5-6-7-8 Veteran
CI-IV AutoX Champ
CI-IV Burnout Champ
St. Jude Donor '07-'10
Memorial day weekend I put mine on nashville superspeedway. I usually fill mine to the top line, then add 3/4 - 1 quart. I dont worry about getting it back out usually as I change it soon after a high speed driving event. I've went for 1k miles with it overfilled like that between autox events too. FWIW, I was hanging mine at 6000rpms in 2nd, 3rd and 4th gear.
