Blown Head Gasket??
05-05-2009 | 06:16 PM
#1
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Joined: Jun 2006
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From: Saucier/Gulfport, MS
Blown Head Gasket??
I think I know the answer to this, but I thought I'd throw it out there to see if I may be missing something....
525SC...Last run of last year, developed a miss...figured a fouled plug...put it away for the winter. Spring time, fresh plugs fire it up...miss still there, maybe a bit of stale fuel. Fresh fuel, fire it up, miss still there. All plug wires check out good. Ok...Soooo, I do a compression check.
#1-125, #3-125, #5-125, #7-125
#2-125, #4-125, #6-000
, #8-60
It appears that I have at least a blown head gasket between 6 & 8. Unless I'm missing something, & it could be something else, it looks like my boating season just got a bit shorter.
Any input on this will be greatly appreciated.
I plan on pulling the top end down on Friday, hopefully it will be nothing more than a head gasket.
525SC...Last run of last year, developed a miss...figured a fouled plug...put it away for the winter. Spring time, fresh plugs fire it up...miss still there, maybe a bit of stale fuel. Fresh fuel, fire it up, miss still there. All plug wires check out good. Ok...Soooo, I do a compression check.
#1-125, #3-125, #5-125, #7-125
#2-125, #4-125, #6-000
, #8-60It appears that I have at least a blown head gasket between 6 & 8. Unless I'm missing something, & it could be something else, it looks like my boating season just got a bit shorter.
Any input on this will be greatly appreciated.
I plan on pulling the top end down on Friday, hopefully it will be nothing more than a head gasket.
05-05-2009 | 06:36 PM
#2
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Joined: Oct 2006
Posts: 5,844
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From: Bradenton Florida
I think I know the answer to this, but I thought I'd throw it out there to see if I may be missing something....
525SC...Last run of last year, developed a miss...figured a fouled plug...put it away for the winter. Spring time, fresh plugs fire it up...miss still there, maybe a bit of stale fuel. Fresh fuel, fire it up, miss still there. All plug wires check out good. Ok...Soooo, I do a compression check.
#1-125, #3-125, #5-125, #7-125
#2-125, #4-125, #6-000, #8-60
It appears that I have at least a blown head gasket between 6 & 8. Unless I'm missing something, & it could be something else, it looks like my boating season just got a bit shorter.
Any input on this will be greatly appreciated.
I plan on pulling the top end down on Friday, hopefully it will be nothing more than a head gasket.
525SC...Last run of last year, developed a miss...figured a fouled plug...put it away for the winter. Spring time, fresh plugs fire it up...miss still there, maybe a bit of stale fuel. Fresh fuel, fire it up, miss still there. All plug wires check out good. Ok...Soooo, I do a compression check.
#1-125, #3-125, #5-125, #7-125
#2-125, #4-125, #6-000
, #8-60It appears that I have at least a blown head gasket between 6 & 8. Unless I'm missing something, & it could be something else, it looks like my boating season just got a bit shorter.
Any input on this will be greatly appreciated.
I plan on pulling the top end down on Friday, hopefully it will be nothing more than a head gasket.
If not ,,i say reversion ,,water . How does the oil look.
#6+8 are most likely the first ones !
05-05-2009 | 09:36 PM
#5
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Joined: Jun 2006
Posts: 497
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From: Saucier/Gulfport, MS
Reversion will cause low or no compression?
I had always thought it to be water intrusion thru the valves, & down past the rings into the oil. I'm not seeing how this would cause a compression problem.
Perhaps I've misunderstood the whole reversion problem. I've also heard that reversion was checked thru a "leak-down" test, not a compression test.
I had always thought it to be water intrusion thru the valves, & down past the rings into the oil. I'm not seeing how this would cause a compression problem.
Perhaps I've misunderstood the whole reversion problem. I've also heard that reversion was checked thru a "leak-down" test, not a compression test.
05-05-2009 | 09:53 PM
#6
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Joined: Oct 2000
Posts: 20,232
Likes: 2,482
From: Omaha/LOTO
Reversion will cause low or no compression?
I had always thought it to be water intrusion thru the valves, & down past the rings into the oil. I'm not seeing how this would cause a compression problem.
Perhaps I've misunderstood the whole reversion problem. I've also heard that reversion was checked thru a "leak-down" test, not a compression test.
I had always thought it to be water intrusion thru the valves, & down past the rings into the oil. I'm not seeing how this would cause a compression problem.
Perhaps I've misunderstood the whole reversion problem. I've also heard that reversion was checked thru a "leak-down" test, not a compression test.
0 is really bad. Even with a blown head gasket, I would expect to see some compression.
No reason to try and guess. Might as well just pull the head.
05-05-2009 | 10:07 PM
#7
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Joined: Apr 2002
Posts: 1,237
Likes: 4
From: Lake of the ozarks
Reversion has a hard time getting in supercharged motors.
We have seen somthing like this before we have two customers blocks in shop now head gasket went first then burnt block between cyl, on the supercharged motor customer did not notice boost went down because it was making up for leak in gasket but the flame travel transfered between cyl and burnt block!
I hope this is not the case but supercharger makes up for some loss of cyl!!!
Good luck keep us posted.
Thumper
We have seen somthing like this before we have two customers blocks in shop now head gasket went first then burnt block between cyl, on the supercharged motor customer did not notice boost went down because it was making up for leak in gasket but the flame travel transfered between cyl and burnt block!
I hope this is not the case but supercharger makes up for some loss of cyl!!!
Good luck keep us posted.
Thumper
05-05-2009 | 10:22 PM
#8
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Joined: May 2001
Posts: 3,358
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From: NO WHERE
do a leak down, zero is bad, just went thru same thing leak down showed 30percent had water in cyl was reversion i think. pressured block heads and intake held 15#30 mins so if it was a head gasket it would had leaked then.
