500efi Saga Continues
11-10-2016 | 08:35 PM
#41
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Joined: Jan 2006
Posts: 3,598
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From: taxachusetts
few questions:
1. Are the guides shown the original iron guides? Or replacement bronze?you have bronze replacements.
2. Is it your opinion that the guides are causing the water corrosion on valves, or is it something else?guides are sticking the valves causing the water to come back up
3. How can you tell compression is off? Gasket is mis-shaped?
1. Are the guides shown the original iron guides? Or replacement bronze?you have bronze replacements.
2. Is it your opinion that the guides are causing the water corrosion on valves, or is it something else?guides are sticking the valves causing the water to come back up
3. How can you tell compression is off? Gasket is mis-shaped?
getrdunn,,you are right,,gm had water running around the unprotected exhaust valve guide.plus you have to watch how you take them out,one side of the casting in the head is ever so slightly smaller.have seen a lot of heads that leaked from guide replacement.
11-10-2016 | 08:45 PM
#44
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Joined: Feb 2009
Posts: 8,356
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From: NW Michigan
the black on the fire ring(silver portion),,especially betw the cylinders.
getrdunn,,you are right,,gm had water running around the unprotected exhaust valve guide.plus you have to watch how you take them out,one side of the casting in the head is ever so slightly smaller.have seen a lot of heads that leaked from guide replacement.
getrdunn,,you are right,,gm had water running around the unprotected exhaust valve guide.plus you have to watch how you take them out,one side of the casting in the head is ever so slightly smaller.have seen a lot of heads that leaked from guide replacement.
These kind of problems eat away at me. Didn't do it before and does now type of thing. Both engines. ???
Drives a guy crazy.
11-10-2016 | 08:48 PM
#45
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Joined: Feb 2009
Posts: 8,356
Likes: 1,515
From: NW Michigan
You'd think especially seeing the back side of the valves but what about the cylinders. You'd surely see evidence of water there as well as Pistons. Any pics of the the Pistons and cylinders OP?
11-10-2016 | 08:50 PM
#46
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Joined: Jun 2010
Posts: 4,806
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the black on the fire ring(silver portion),,especially betw the cylinders.
getrdunn,,you are right,,gm had water running around the unprotected exhaust valve guide.plus you have to watch how you take them out,one side of the casting in the head is ever so slightly smaller.have seen a lot of heads that leaked from guide replacement.
getrdunn,,you are right,,gm had water running around the unprotected exhaust valve guide.plus you have to watch how you take them out,one side of the casting in the head is ever so slightly smaller.have seen a lot of heads that leaked from guide replacement.
11-10-2016 | 09:01 PM
#48
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Joined: Apr 2005
Posts: 2,150
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From: Northport N.Y.
Dropped off heads yesterday with machine shop... his first guess was valve guides. He was right. See picture below. Not sure why this want checked during the first top end rebuild. Would have saved me a lot of time and money.
https://i.imgur.com/3rmvPBv.jpg
He is checking other things as well (i.e. Springs, valve job, valves, seals, etc).
https://i.imgur.com/3rmvPBv.jpg
He is checking other things as well (i.e. Springs, valve job, valves, seals, etc).
wow I did not see this that's pretty bad
