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Ci head repair? #2742270
02/12/20 01:54 PM
02/12/20 01:54 PM
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Wirenut Offline OP
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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



D85D75FD-7237-41EC-9F40-C24256E531A4.jpeg
Last edited by Wirenut; 02/12/20 03:30 PM.
Re: Ci head repair? [Re: Wirenut] #2742336
02/12/20 03:51 PM
02/12/20 03:51 PM
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So. Burlington, Vt.
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fast68plymouth Offline
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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
Re: Ci head repair? [Re: fast68plymouth] #2742382
02/12/20 05:54 PM
02/12/20 05:54 PM
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Wirenut Offline OP
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Originally Posted by fast68plymouth
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

Re: Ci head repair? [Re: Wirenut] #2742387
02/12/20 06:14 PM
02/12/20 06:14 PM
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fast68plymouth Offline
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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
Re: Ci head repair? [Re: fast68plymouth] #2742397
02/12/20 07:05 PM
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Wirenut Offline OP
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Do you mean pressure test on the coolant side or valve to valve seat seal?

Re: Ci head repair? [Re: Wirenut] #2742523
02/13/20 09:43 AM
02/13/20 09:43 AM
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Marion, South Carolina [><]
an8sec70cuda Offline
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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. twocents


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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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Wirenut Offline OP
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Originally Posted by an8sec70cuda
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. twocents


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.

Re: Ci head repair? [Re: Wirenut] #2742637
02/13/20 06:28 PM
02/13/20 06:28 PM
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TRENDZ Offline
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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"
Re: Ci head repair? [Re: Wirenut] #2742671
02/13/20 08:40 PM
02/13/20 08:40 PM
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CSK Offline
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Originally Posted by Wirenut
Originally Posted by an8sec70cuda
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. twocents


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

Re: Ci head repair? [Re: TRENDZ] #2742727
02/14/20 08:05 AM
02/14/20 08:05 AM
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Wirenut Offline OP
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I don’t understand? If I only got to 150 or so why would it be different than operating temp.
Thanks for your reply
G

Re: Ci head repair? [Re: CSK] #2742728
02/14/20 08:07 AM
02/14/20 08:07 AM
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Wirenut Offline OP
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Originally Posted by csk
Originally Posted by Wirenut
Originally Posted by an8sec70cuda
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. twocents


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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