need help diagnosing a engine problem
Thread Starter
Instructor
Joined: Dec 2005
Posts: 147
Likes: 0
From: San Antonio Texas
need help diagnosing a engine problem
I have recently started seeing white smoke under heavy rpm/acceleration. I and almost 100% positive it is not water so I guess the correct term would be grey smoke. it only comes out of one tail pipe and dose not smoke at idle or moderate acceleration. only when I hammer it. could this be blow by? by the way my engine specs are as follows
383 LT1 (out of a '94 camaro) w/ 11.7:1 compression on pump gas
LT1 aluminum heads flowing 270i/200e w/ 2.2/1.6 valves
CC306 cam (230i/244e on a 112 LSA w/ lift of .544/.576)
Cyl. Chamber Vol. 54cc
TRW4 4.030 pistons (-4cc valve relief)
Eagle 4340 Rods
383 LT1 (out of a '94 camaro) w/ 11.7:1 compression on pump gas
LT1 aluminum heads flowing 270i/200e w/ 2.2/1.6 valves
CC306 cam (230i/244e on a 112 LSA w/ lift of .544/.576)
Cyl. Chamber Vol. 54cc
TRW4 4.030 pistons (-4cc valve relief)
Eagle 4340 Rods
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
How are you 100% sure it's not water?
Be very specific when describing the color. Any white at all means water, and being on one side only it indicates a head gasket.
Blow by, or oil being burned, would be a different color.
Be very specific when describing the color. Any white at all means water, and being on one side only it indicates a head gasket.
Blow by, or oil being burned, would be a different color.
Thread Starter
Instructor
Joined: Dec 2005
Posts: 147
Likes: 0
From: San Antonio Texas
my coolant level has not droped at all and I have been checking it over the past couple of months and I have not seen any water in the oil. the smoke dose look white but it linges for a while as much as I can tell from the 80+ I am usualy doing when this happens.
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
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That cam and 11.7 compression sure seem like you're living on the edge for cylinder pressure. It sure sounds like blowby....probably caused by detonation damage.
What do plugs look like on that bank? How do they compare?
My gut tells me we have some dead rings/scuffing etc on at least one of those cylinders...but likely all will show signs of damage. Good thing you have forged pistons..hypers would have disentegrated by now.
At this point your best bet is to pull plugs to check, do a compression test at least..or preferably a leakdown test to determine cylinder health.
Let us know what you find......
JIM
What do plugs look like on that bank? How do they compare?
My gut tells me we have some dead rings/scuffing etc on at least one of those cylinders...but likely all will show signs of damage. Good thing you have forged pistons..hypers would have disentegrated by now.
At this point your best bet is to pull plugs to check, do a compression test at least..or preferably a leakdown test to determine cylinder health.
Let us know what you find......
JIM
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Thread Starter
Instructor
Joined: Dec 2005
Posts: 147
Likes: 0
From: San Antonio Texas
I am relatively new to corvettes and cars in general. I purchased this car with the engine already in it. Sounds like I have a problem that is going to be way over my head. dose anyone know a good mechanic in the San Antonio area who could diagnose or maybe solve this issue?
Race Director
Joined: Oct 2000
Posts: 15,017
Likes: 79
From: central FL, near the beach.
ever watch a race and the announcer, upon seeing smoke, says
SO & SO JUST BLEW HIS ENGINE!
that's YOU!
when u rebuild, go down to 10.7-11.1:1
it takes a pro to run higher!
the announcer continues:
IF HE DOESNT PIT SOON, HE WILL GET THE BLACK FLAG(ordering him in), SO HE DOESNT GET OIL AND DEBRIS ALL OVER THE TRACK
i had the white smoke, only much worse happen to me at the drags: turbocharger bearing failed, dumped 1 quart of oil into the exhaust; the entire raceway park was covered in white smoke for ~5 minutes. no racing until it cleared. visibility was 10 feet
announcer said HE JUST BLEW HIS TURBO
SO & SO JUST BLEW HIS ENGINE!
that's YOU!
when u rebuild, go down to 10.7-11.1:1
it takes a pro to run higher!
the announcer continues:
IF HE DOESNT PIT SOON, HE WILL GET THE BLACK FLAG(ordering him in), SO HE DOESNT GET OIL AND DEBRIS ALL OVER THE TRACK
i had the white smoke, only much worse happen to me at the drags: turbocharger bearing failed, dumped 1 quart of oil into the exhaust; the entire raceway park was covered in white smoke for ~5 minutes. no racing until it cleared. visibility was 10 feet
announcer said HE JUST BLEW HIS TURBO
Last edited by Matt Gruber; Aug 30, 2007 at 10:03 AM.
