Dropped valve head repair
06-04-2012, 10:54 PM
#6
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The story I was told is that this head was done at AMS years back, and it it has passed from one owner to the next,been loaded at least once since AMS built it. Also it has been through a couple shops.
The last incarnation it was loaded with ST valves, Springs and Ti retainers.
But since the casting had good money spent on having it ported at AMS, the customer feels that having this head fixed would be cheaper than starting over.
Also this head was not set up properly last time, you can see where the followers were riding on the Ti retainers.
What would cause this is the tip height being to tall then grinding the valve tip height down to bring tip height into spec.
Yes I get lucky with a good pic now and then.
I have been trying some of the tips you all have shared with me.
The last incarnation it was loaded with ST valves, Springs and Ti retainers.
But since the casting had good money spent on having it ported at AMS, the customer feels that having this head fixed would be cheaper than starting over.
Also this head was not set up properly last time, you can see where the followers were riding on the Ti retainers.
What would cause this is the tip height being to tall then grinding the valve tip height down to bring tip height into spec.
Yes I get lucky with a good pic now and then.
I have been trying some of the tips you all have shared with me.
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06-05-2012, 01:02 AM
#8
My head that is now fixed (blurry image due to old, old mobile)
Most probably a lash cap collapsed (very thin), the next hing to break the OE retainer, then the valve dropped ... (half the seat was found in the intake)
I't been to the welder three times before it stopped leaking. New guide to say the least
Many things can be fixed, if the castings are of good quality, which our heads are.
Most probably a lash cap collapsed (very thin), the next hing to break the OE retainer, then the valve dropped ... (half the seat was found in the intake)
I't been to the welder three times before it stopped leaking. New guide to say the least
Many things can be fixed, if the castings are of good quality, which our heads are.
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06-06-2012, 08:22 PM
#9
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More info on the head
4G63 Head Inspection
#3
This head was damaged by a dropped valve.
Due to the cost of the port work involved in this head, it was deemed feasible to save the head and fix it.
The head is loaded with Super-Tech valve train, Valves, Duel Valve springs and Ti retainers
Some of the retainers suffered some damage where the roller followers hit.
7 Intake retainers and 1 Exhaust retainer were hit.
Also several of the intake valve tips show damage. 4 of them were mushroomed so bad they would not slide thru the guide.
I had to file the lip off so I could remove them.
No shims were found under the spring seats.
The guides are cast iron and were ground on a angle, making the guide shorter and not supporting the valve stem fully.
Valve tip height was found to be with in specs for the most part
Intake 1.914 – 1.926
Exhaust 1.908 – 1.924
There is also damage to the spark plug hole, an insert will have to be installed.
It did have vition blue seals installed.
The rebuild will be fairly straight forward.
The guides will be removed and replaced with bronze guides
The 4 seats in #4 cylinder will be removed and replaced with high nickel alloy seats.
Some welding will be done to fill in deep pits and gouges, and dressed out.
A full multi angle valve job will be done.
A new set of Stainless Steel valves will be used.
#3
This head was damaged by a dropped valve.
Due to the cost of the port work involved in this head, it was deemed feasible to save the head and fix it.
The head is loaded with Super-Tech valve train, Valves, Duel Valve springs and Ti retainers
Some of the retainers suffered some damage where the roller followers hit.
7 Intake retainers and 1 Exhaust retainer were hit.
Also several of the intake valve tips show damage. 4 of them were mushroomed so bad they would not slide thru the guide.
I had to file the lip off so I could remove them.
No shims were found under the spring seats.
The guides are cast iron and were ground on a angle, making the guide shorter and not supporting the valve stem fully.
Valve tip height was found to be with in specs for the most part
Intake 1.914 – 1.926
Exhaust 1.908 – 1.924
There is also damage to the spark plug hole, an insert will have to be installed.
It did have vition blue seals installed.
The rebuild will be fairly straight forward.
The guides will be removed and replaced with bronze guides
The 4 seats in #4 cylinder will be removed and replaced with high nickel alloy seats.
Some welding will be done to fill in deep pits and gouges, and dressed out.
A full multi angle valve job will be done.
A new set of Stainless Steel valves will be used.
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