Ci head repair?
#2742270
02/12/20 01:54 PM
02/12/20 01:54 PM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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Hi Folks While performing a minor valve job we discovered cracks in the seats of 3 intake valves . The pic is typical of all three. My machinist said he can replace the seat but feels the crack is in the head as well. Cast iron Indy 440-1c .
Why did this happen?
Has anyone had any luck repairing this ?
Does anyone know the depth of the original valve seat on this head
Thanks for looking
Last edited by Wirenut; 02/12/20 03:30 PM.
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Re: Ci head repair?
[Re: Wirenut]
#2742336
02/12/20 03:51 PM
02/12/20 03:51 PM
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Joined: Jan 2003
Posts: 14,493 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,493
So. Burlington, Vt.
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Happens with Dart SBC heads all the time. Really hot on one side, much cooler incoming air and fuel on the other side.
If it doesn’t leak on a pressure test, put some seats in them and run it(or not).
We’ve had guys run the Dart heads in oval track cars with the cracks opened up way more than that for years..... without putting seats in.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Ci head repair?
[Re: fast68plymouth]
#2742382
02/12/20 05:54 PM
02/12/20 05:54 PM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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Happens with Dart SBC heads all the time. Really hot on one side, much cooler incoming air and fuel on the other side.
If it doesn’t leak on a pressure test, put some seats in them and run it(or not).
We’ve had guys run the Dart heads in oval track cars with the cracks opened up way more than that for years..... without putting seats in. Thanks for that info. Spoke to a machinist that said about the same thing, but added to try and get a 1/4” depth seat into it. I’m just concerned that may go to deep and into a water passage? Anybody been there ? G
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Re: Ci head repair?
[Re: Wirenut]
#2742387
02/12/20 06:14 PM
02/12/20 06:14 PM
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Joined: Jan 2003
Posts: 14,493 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,493
So. Burlington, Vt.
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If it pressure tested good...... I’d just run it.
If it’s leaking already, then it’s time for welding or pinning.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Ci head repair?
[Re: Wirenut]
#2742523
02/13/20 09:43 AM
02/13/20 09:43 AM
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Joined: Jan 2003
Posts: 13,357 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,357
Marion, South Carolina [><]
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I think he's referring to the coolant side. Many heads crack like that but never leak water. Like Dwayne said, if it doesn't leak, cut the seats and run it. The magnum era small block heads were bad for this. In my experience, pressure checking a cast iron head will only show a leak if the crack is pretty bad. I have pressure checked cast iron heads that didn't leak when checked, but did leak when they got hot when running. Just saying if you weren't having any leaking issues when they were ran last, and they check good, then run em. Putting a seat in it would be good only if the relief cut for the seat cut out all of the original crack.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Ci head repair?
[Re: an8sec70cuda]
#2742633
02/13/20 06:17 PM
02/13/20 06:17 PM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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I think he's referring to the coolant side. Many heads crack like that but never leak water. Like Dwayne said, if it doesn't leak, cut the seats and run it. The magnum era small block heads were bad for this. In my experience, pressure checking a cast iron head will only show a leak if the crack is pretty bad. I have pressure checked cast iron heads that didn't leak when checked, but did leak when they got hot when running. Just saying if you weren't having any leaking issues when they were ran last, and they check good, then run em. Putting a seat in it would be good only if the relief cut for the seat cut out all of the original crack. Thanks for the reply and sharing Your experience. I spoke with a gentleman at Indy today who (contrary to my past experiences) was really helpful. Said about the same as both of you. Happens all the time, Pressure check and re-seat. What about heating the crack while under pressure ? I didnt notice any performance issues and only had them apart for inspection due to a possible valve geometry issue, BUT now that I think of it the water may have been a little low when I pulled the radiator.
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Re: Ci head repair?
[Re: Wirenut]
#2742637
02/13/20 06:28 PM
02/13/20 06:28 PM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
master
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master
Joined: Jan 2005
Posts: 2,540
Milwaukee WI
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Do not heat that crack. If it wasn’t cracked through before, it will be after doing that.
"use it 'till it breaks, replace as needed"
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Re: Ci head repair?
[Re: Wirenut]
#2742671
02/13/20 08:40 PM
02/13/20 08:40 PM
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Joined: Aug 2011
Posts: 2,853 Pattison Texas
CSK
master
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master
Joined: Aug 2011
Posts: 2,853
Pattison Texas
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I think he's referring to the coolant side. Many heads crack like that but never leak water. Like Dwayne said, if it doesn't leak, cut the seats and run it. The magnum era small block heads were bad for this. In my experience, pressure checking a cast iron head will only show a leak if the crack is pretty bad. I have pressure checked cast iron heads that didn't leak when checked, but did leak when they got hot when running. Just saying if you weren't having any leaking issues when they were ran last, and they check good, then run em. Putting a seat in it would be good only if the relief cut for the seat cut out all of the original crack. Thanks for the reply and sharing Your experience. I spoke with a gentleman at Indy today who (contrary to my past experiences) was really helpful. Said about the same as both of you. Happens all the time, Pressure check and re-seat. What about heating the crack while under pressure ? I didnt notice any performance issues and only had them apart for inspection due to a possible valve geometry issue, BUT now that I think of it the water may have been a little low when I pulled the radiator. Indy has new owners
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: Ci head repair?
[Re: CSK]
#2742728
02/14/20 08:07 AM
02/14/20 08:07 AM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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I think he's referring to the coolant side. Many heads crack like that but never leak water. Like Dwayne said, if it doesn't leak, cut the seats and run it. The magnum era small block heads were bad for this. In my experience, pressure checking a cast iron head will only show a leak if the crack is pretty bad. I have pressure checked cast iron heads that didn't leak when checked, but did leak when they got hot when running. Just saying if you weren't having any leaking issues when they were ran last, and they check good, then run em. Putting a seat in it would be good only if the relief cut for the seat cut out all of the original crack. Thanks for the reply and sharing Your experience. I spoke with a gentleman at Indy today who (contrary to my past experiences) was really helpful. Said about the same as both of you. Happens all the time, Pressure check and re-seat. What about heating the crack while under pressure ? I didnt notice any performance issues and only had them apart for inspection due to a possible valve geometry issue, BUT now that I think of it the water may have been a little low when I pulled the radiator. Indy has new owners Yes that’s what I heard
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