Does this sound like an Accusump fix?
02-28-2007, 08:00 PM
#1
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Does this sound like an Accusump fix? ***FOUND THE PROBLEM!***
I just picked up a '99 FRC set up as a full-tilt SM2 car from Monks on this forum. I debuted the car @ an NCCC test-n-tune day, where it absolutely dominated.
It was 1.6 secs quicker than an E-mod SC Stalker, driven by Dennis 'Stalker' Brunton himself--I was very pleased to say the least w/ the car, but...
I was experiencing somewhat severe lifter clatter towards the end of the run, the motor would also start to 'flatten out' & become rough as well. After the run, I would let it idle & rev it up a few times & the condition seemed to clear up. The oil pressure was good all the while.
The surface was concrete & the car was on new 710s, so the grip & transitions were immense.
The motor is a 382 stroker that's fresh & was built & broken in properly.
Will an accusump setup take care of this issue, or is something else possibly going on here?
A few pics:
It was 1.6 secs quicker than an E-mod SC Stalker, driven by Dennis 'Stalker' Brunton himself--I was very pleased to say the least w/ the car, but...
I was experiencing somewhat severe lifter clatter towards the end of the run, the motor would also start to 'flatten out' & become rough as well. After the run, I would let it idle & rev it up a few times & the condition seemed to clear up. The oil pressure was good all the while.
The surface was concrete & the car was on new 710s, so the grip & transitions were immense.
The motor is a 382 stroker that's fresh & was built & broken in properly.
Will an accusump setup take care of this issue, or is something else possibly going on here?
A few pics:
Last edited by GTB/ZR-1; 03-25-2007 at 11:05 AM.
02-28-2007, 10:04 PM
#2
Le Mans Master
i wouldn't bet my motor on my opinion, but i'm thinking more along the lines of fuel starvation. Were you running the car with only a little gas in the tank?
02-28-2007, 10:11 PM
#3
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Thx
02-28-2007, 10:22 PM
#4
Melting Slicks
Maybe,maybe not..........What rpm were you seeing/sustaining ???? What kind of oil pressure is the thing making at idle after the run???? What is the oil temp ??? Idle speed ?? Is there enough valve spring for the camshaft ??
Did you have any higher-rpm sweepers ?? Or would the engine just flatten out by itself at high rpm with no turns involved ???? If it is oil starving at an autocross I would be suprised. Does it have an LS2 pan or the LS1/LS6 batwing ?? I fit is losing oil pressure on course then an accusump will help.
Done asking questions....your it .
Did you have any higher-rpm sweepers ?? Or would the engine just flatten out by itself at high rpm with no turns involved ???? If it is oil starving at an autocross I would be suprised. Does it have an LS2 pan or the LS1/LS6 batwing ?? I fit is losing oil pressure on course then an accusump will help.
Done asking questions....your it .
02-28-2007, 10:39 PM
#5
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Maybe,maybe not..........What rpm were you seeing/sustaining ???? What kind of oil pressure is the thing making at idle after the run???? What is the oil temp ??? Idle speed ?? Is there enough valve spring for the camshaft ??
Did you have any higher-rpm sweepers ?? Or would the engine just flatten out by itself at high rpm with no turns involved ???? If it is oil starving at an autocross I would be suprised. Does it have an LS2 pan or the LS1/LS6 batwing ?? I fit is losing oil pressure on course then an accusump will help.
Done asking questions....your it .
Did you have any higher-rpm sweepers ?? Or would the engine just flatten out by itself at high rpm with no turns involved ???? If it is oil starving at an autocross I would be suprised. Does it have an LS2 pan or the LS1/LS6 batwing ?? I fit is losing oil pressure on course then an accusump will help.
Done asking questions....your it .
There were very high-speed sweepers involved, and a few violent transitions @ speed as well. This was not a typical speed-maintainence course--it was waaay illegal--Vette guys having a little fun @ the test-n-tune.
I believe it has the LS1 pan. The rev limiter is set @ 7050, and I drive like you--so it stays there
Oil temp was low 220s & pressure was low 20s after runs (went back to 200ish & mid 30s waiting in line to go again). Idles @ 925 & springs/rockers are definitely sufficient for the setup.Back to you & thx...
02-28-2007, 11:42 PM
#6
Melting Slicks
George,
I am concerned that during your runs @ high rpm that the valve train started making noise.. If your lifters were collapsing because the lifters were lacking oil , think about your engine bearings
I've knocked the dog-snot out of the '03 car at events as your talking of and haven't had that occurance....
With that said , I would be draining your oil and inspecting it for bearing material to make sure no other damage occured. If you had significant damage you would already know about it. Anyhoo, change the oil and inspect for alot of "silver"......
I am assuming that you were slightly over full with your oil level.
If all is OK, I would probably suggest installing an accusump. I would get a 3 quart unit, which can be mounted in either left or right front fenders. I have installed them on either side...its better to add wieght (which is what you'll be doing) on the right side of the vehicle , but this will require that you relocate the PCM and the TAC module. On my RR car , I relocated these under the passenger dash. It is easier to mount on the left side , obviously.
I am concerned that during your runs @ high rpm that the valve train started making noise.. If your lifters were collapsing because the lifters were lacking oil , think about your engine bearings
I've knocked the dog-snot out of the '03 car at events as your talking of and haven't had that occurance....With that said , I would be draining your oil and inspecting it for bearing material to make sure no other damage occured. If you had significant damage you would already know about it. Anyhoo, change the oil and inspect for alot of "silver"......
I am assuming that you were slightly over full with your oil level.
If all is OK, I would probably suggest installing an accusump. I would get a 3 quart unit, which can be mounted in either left or right front fenders. I have installed them on either side...its better to add wieght (which is what you'll be doing) on the right side of the vehicle , but this will require that you relocate the PCM and the TAC module. On my RR car , I relocated these under the passenger dash. It is easier to mount on the left side , obviously.
03-01-2007, 05:14 PM
#7
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Well, a preliminary ck was the oil level was a bit above the fill line & I didn't notice any shavings @ all. I'll change the oil tomorrow & have a better look.
Hopefully the accusump will fix the issue. The car makes 450/450 & is extremely well-sorted & easy to drive @ 10/10ths, so I hope that's all that 'up' w/ it...
Thx (again!) Danny & I'll keep this thread posted
Hopefully the accusump will fix the issue. The car makes 450/450 & is extremely well-sorted & easy to drive @ 10/10ths, so I hope that's all that 'up' w/ it...
Thx (again!) Danny & I'll keep this thread posted
03-01-2007, 06:18 PM
#8
I have been having oil pressure issues also. The real fix IMHO for me was a dry sump which I have installed.The problem with the LS engines as yall already know is that the last thing to get oil is the front main. I purchashed my car new and it has never seen the street since April of 03 thanks to Danny Pop. I dont know if you remember me Danny , but you instructed me at Corvette Bash in 2002. I had a red Zo6 and came in second place in the autox event. Since that time I started autoxing and been doing a lot of club racing with PBOC. Thanks for the help back then,you have helped me spend my retirement. David Leonard
Last edited by vette6aut0x; 03-01-2007 at 06:25 PM.
03-01-2007, 08:43 PM
#9
Race Director
if your gauge isn't losing pressure, I doubt it is the oil. You could be starving fuel, or you could be out-performing the pump. I can't imagine it happening on an autocross, but extended acceleration can drain the fuel rails of adequate pressure, which gives a "flat" sensation. Lingenfelter has a in-tank replacement walbro that works well.
Accusump is never a bad idea. Great way to prelube your engine, plus the benefits of extra lubrication if you do create a starvation situation.
Accusump is never a bad idea. Great way to prelube your engine, plus the benefits of extra lubrication if you do create a starvation situation.
03-01-2007, 09:42 PM
#10
Melting Slicks
I have been having oil pressure issues also. The real fix IMHO for me was a dry sump which I have installed.The problem with the LS engines as yall already know is that the last thing to get oil is the front main. I purchashed my car new and it has never seen the street since April of 03 thanks to Danny Pop. I dont know if you remember me Danny , but you instructed me at Corvette Bash in 2002. I had a red Zo6 and came in second place in the autox event. Since that time I started autoxing and been doing a lot of club racing with PBOC. Thanks for the help back then,you have helped me spend my retirement. David Leonard
Sorry to be so infectious........I am glad you found a way to spend your retirement........and your money
Corvette Museum Birthday Bash 2002 was bittersweet for me. The Evolution School, Autocross, and Super Tuner Shootout were great.........the aftermath and rules changing of the Shootout between the event and the awards were not.
Have fun, I am sure we will cross paths again my friend.
03-01-2007, 10:23 PM
#12
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George,
I don't think it is a oil pressure issue. I ran the car plenty hard
in sweeping high speed turns and never had any issues with lifter
noise. You are reving the motor allot harder than I was though.
I raced at Roebling Road on Thanksgiving with no issues at all.
The lifters in the motor are brand new Comp 750's It sounds like a
lifter is collapsing. If you can tell what side the noise is coming from,
it may be worth pulling the valve cover and checking the Jesel rocker
stand bolts.
PM sent!
Russ
[QUOTE
I was experiencing somewhat severe lifter clatter towards the end of the run, the motor would also start to 'flatten out' & become rough as well. After the run, I would let it idle & rev it up a few times & the condition seemed to clear up. The oil pressure was good all the while.
I don't think it is a oil pressure issue. I ran the car plenty hard
in sweeping high speed turns and never had any issues with lifter
noise. You are reving the motor allot harder than I was though.
I raced at Roebling Road on Thanksgiving with no issues at all.
The lifters in the motor are brand new Comp 750's It sounds like a
lifter is collapsing. If you can tell what side the noise is coming from,
it may be worth pulling the valve cover and checking the Jesel rocker
stand bolts.
PM sent!
Russ
[QUOTE
I was experiencing somewhat severe lifter clatter towards the end of the run, the motor would also start to 'flatten out' & become rough as well. After the run, I would let it idle & rev it up a few times & the condition seemed to clear up. The oil pressure was good all the while.
03-25-2007, 11:15 AM
#14
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I was surprised to find this as the culprit--it became easy to diagnose, once it 'went' fully!
Sorry, it's a little blurry, but there must have been a hairline crack @ first in the A.I.R. setup that made the condition intermittent (expansion/contraction).
Once it really let go, I thought I had done something really nasty to the engine.
As I was loading it on the trailer, I asked my buddy if it sounded like a collapsed lifter to him as well. He gave me a puzzled look & said it sounded like an exhaust leak--but I said it was way too high to be that--until I lifted the hood...
Welded it back up & hopefully no more issues.
Thx to all for the suggestions
Sorry, it's a little blurry, but there must have been a hairline crack @ first in the A.I.R. setup that made the condition intermittent (expansion/contraction).
Once it really let go, I thought I had done something really nasty to the engine.
As I was loading it on the trailer, I asked my buddy if it sounded like a collapsed lifter to him as well. He gave me a puzzled look & said it sounded like an exhaust leak--but I said it was way too high to be that--until I lifted the hood...
Welded it back up & hopefully no more issues.
Thx to all for the suggestions
Last edited by GTB/ZR-1; 03-25-2007 at 11:52 AM.
