Re: Valves or head gasket or ??? failure
[Re: NITROUSN]
#3148321
06/02/23 09:50 PM
06/02/23 09:50 PM
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Joined: Jan 2003
Posts: 296 Michigan
Ply36
OP
enthusiast
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OP
enthusiast
Joined: Jan 2003
Posts: 296
Michigan
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Sorry, forgot to mention psi on the other cylinders, they were 150 after just a few seconds of cranking on each cylinder. One cylinder I cranked a little longer and it showed 160 or so before I let up.
I think it was gradual until it became obvious. Performance seemed to be tailing off which is why I did the plugs and wires change
Last edited by Ply36; 06/02/23 09:59 PM.
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Re: Valves or head gasket or ??? failure
[Re: Ply36]
#3148326
06/02/23 10:04 PM
06/02/23 10:04 PM
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Joined: Jan 2003
Posts: 18,423 UPPER MICHIGAN, MARQUETTE COUN...
NITROUSN
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 18,423
UPPER MICHIGAN, MARQUETTE COUN...
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Sorry, forgot to mention psi on the other cylinders, they were 150 after just a few seconds of cranking on each cylinder. One cylinder I cranked a little longer and it showed 160 or so before I let up.
I think it was gradual until it became obvious. Performance seemed to be tailing off which is why I did the plugs and wires change Leak down test will tell you if its a valve or gasket between the cylinders. I would not run it. Blowing between the cylinders wears the block and head surfaces.
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Re: Valves or head gasket or ??? failure
[Re: Cab_Burge]
#3148417
06/03/23 02:27 PM
06/03/23 02:27 PM
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Joined: Sep 2003
Posts: 19,421 north of coder
moparx
"Butt Crack Bob"
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"Butt Crack Bob"
Joined: Sep 2003
Posts: 19,421
north of coder
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i'm in the head gasket camp as well. as has been said, don't drive it. that will cause a groove to be formed on both the block and head surface, [if it hasn't happened already, driving it the 20 miles you stated] requiring the engine to come out to get the deck milled. that may have ruined the block if the groove is way deep, or may cause you to use head gasket spacers if they are available for that engine.
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Re: Valves or head gasket or ??? failure
[Re: Ply36]
#3150649
06/11/23 09:49 PM
06/11/23 09:49 PM
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Joined: Oct 2005
Posts: 4,946 WI
Dcuda69
master
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master
Joined: Oct 2005
Posts: 4,946
WI
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Got the head off and.... yup, it's the head gasket. So ugly I had to take a picture of it. There is a section of gasket missing between cylinders 6 and 8 that is about 3/4 of an inch at its widest point. It appears that the head and the block made it thru without any damage. I'm going to have the head checked out by a shop and they can tell me if it's any good.
It's a Fel-Pro gasket (#7728) and I can't seem to find anything with that part number on the FEL - PRO website. Anyone know of another source?
Put a straight edge on the block also!
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Re: Valves or head gasket or ??? failure
[Re: Dcuda69]
#3150659
06/11/23 10:58 PM
06/11/23 10:58 PM
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Joined: May 2012
Posts: 1,832 South Bend
John Brown
top fuel
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top fuel
Joined: May 2012
Posts: 1,832
South Bend
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It's a Fel-Pro gasket (#7728) and I can't seem to find anything with that part number on the FEL - PRO website. Anyone know of another source?
Here's your head gasket. One Felpro 7728S and one Victor 1109. https://www.ebay.com/itm/295446382328
July 19th should be "Drive Like Rockford Day". R.I.P. Jimmie.
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Re: Valves or head gasket or ??? failure
[Re: Dcuda69]
#3150846
06/12/23 01:45 PM
06/12/23 01:45 PM
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Joined: Aug 2003
Posts: 43,204 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,204
Bend,OR USA
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Got the head off and.... yup, it's the head gasket. So ugly I had to take a picture of it. There is a section of gasket missing between cylinders 6 and 8 that is about 3/4 of an inch at its widest point. It appears that the head and the block made it thru without any damage. I'm going to have the head checked out by a shop and they can tell me if it's any good.
It's a Fel-Pro gasket (#7728) and I can't seem to find anything with that part number on the FEL - PRO website. Anyone know of another source?
Put a straight edge on the block also! You should use the thinnest feeler gauge you have, I use a .0015 or .0020, to see if the block and head is flat or not between every cylinder wall on the thinnest part as well as the rest of the block and on the head also, especially where the gasket blew out Hopefully they are not hurt
Last edited by Cab_Burge; 06/12/23 01:45 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Valves or head gasket or ??? failure
[Re: Cab_Burge]
#3150963
06/12/23 07:03 PM
06/12/23 07:03 PM
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Joined: May 2019
Posts: 6,267 nowhere
Sniper
master
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master
Joined: May 2019
Posts: 6,267
nowhere
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Got the head off and.... yup, it's the head gasket. So ugly I had to take a picture of it. There is a section of gasket missing between cylinders 6 and 8 that is about 3/4 of an inch at its widest point. It appears that the head and the block made it thru without any damage. I'm going to have the head checked out by a shop and they can tell me if it's any good.
It's a Fel-Pro gasket (#7728) and I can't seem to find anything with that part number on the FEL - PRO website. Anyone know of another source?
Put a straight edge on the block also! You should use the thinnest feeler gauge you have, I use a .0015 or .0020, to see if the block and head is flat or not between every cylinder wall on the thinnest part as well as the rest of the block and on the head also, especially where the gasket blew out Hopefully they are not hurt Shine a flashlight there, you'll see any gap
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Re: Valves or head gasket or ??? failure
[Re: Sniper]
#3151155
06/13/23 11:28 AM
06/13/23 11:28 AM
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Joined: Jan 2003
Posts: 296 Michigan
Ply36
OP
enthusiast
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OP
enthusiast
Joined: Jan 2003
Posts: 296
Michigan
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I did not re-torque the heads after startup. There was a couple of years between engine build and starting it, and in that time I don't recall that ever being mentioned. Still, that's on me
My friend that owns the performance engine shop ran a straight edge over the block, and using a feeler gauge, he could not get the .0020 between the block and the edge, but with the .0015 he could make some progress (with a little effort) but not much. He felt the block was okay.
I believe the root cause of all this was the head. At some point in the engine's history, there was a shallow crack in the cylinder head in the area between #6 and #8. It was repaired, my friend thought they used 'pins' to fill the slight gap. It ran nearly the whole width of the head surface between the two cylinders. The head was then resurfaced to remove any excess metal in the repaired area. But they didn't get it all or as good as they could have. Running a finger over the area directly between the two cylinders you ciould still feel very slight unevenness in the repaired area. You guys know the rest.
Not sure if this was a contributing factor, but some of the cooling passage were blocked in the area of #8. This head buildup may have added more stress on the head and the gasket. I didn't drive the car that much so I never had the cooling system flushed in the approximately 15K miles the engine had on it.
I have some spare engines, heads, etc. to hopefully get me out of this. Some are 241, some are 271. I understand the heads of the 271 will fit on the 241 block. Will the larger capacity of the 271 heads be worth it?
I want to thank all who replied. I appreciate your input.
Last edited by Ply36; 06/13/23 11:30 AM.
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