Do New LS7s still have the valve guide issue?
Thread Starter
Teching In
Joined: Sep 2020
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Do New LS7s still have the valve guide issue? Hi all
If I buy a brand new LS7 today, straight from GMPP should I still expect to have to deal with the valve guide issue?
I thought they had fixed it at some point over the last 10+ years that GM has been selling LS7 engines and LS7 heads.
Appreciate any feedback. Been getting mixed opinions from shops/engine builders.
If I buy a brand new LS7 today, straight from GMPP should I still expect to have to deal with the valve guide issue?
I thought they had fixed it at some point over the last 10+ years that GM has been selling LS7 engines and LS7 heads.
Appreciate any feedback. Been getting mixed opinions from shops/engine builders.
They never 100% admitted a root cause. I ve heard and read alot of theories. Including my engine builders personal theory. Id order up that motor and have the heads gone thru with YOUR trusted cylinder head guru.
Thread Starter
Teching In
Joined: Sep 2020
Posts: 2
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yea true- I know they never admitted it, but any idea if they went ahead and fixed it behind the scenes?
Would be pretty insane if they continued to sell LS7 heads and crate engines with the fucked heads non-stop until this day....
Would be pretty insane if they continued to sell LS7 heads and crate engines with the fucked heads non-stop until this day....
The problem is, so few failed vs. how many sold kinda thing. So I doubt any thing has changed. My engine builder had a pretty plausible theory n good track record on the ones he "fixed". PM me if you want his number. He ll talk to you about it n mite be interested in the work.
From what I have researched and know from a couple very reputable sources, the issues was a few different things, but to answer your question, no they do not have the problem any more.
1) The guide and seat were not concentric. Meaning the valve would seat "off-center" and flex the head of the valve until it broke.
I was told that the machining/fixturing of the head at the manufacturing facility in Canada was the issue and it had been corrected back around 2010 I believe.
2) The surface finish of the Del West valve stems were too rough so the guides would wear excessively and cause a similar issue where the valve would seat off-center and flex and break the valve head off.
This is why Del West offered "free polishing" of the valves to restore the surface finish to an acceptable level.
3) Broken valve springs caused some of the "valve drop" issues as well which made people think that the valve broke when in reality, the spring broke first.
1) The guide and seat were not concentric. Meaning the valve would seat "off-center" and flex the head of the valve until it broke.
I was told that the machining/fixturing of the head at the manufacturing facility in Canada was the issue and it had been corrected back around 2010 I believe.
2) The surface finish of the Del West valve stems were too rough so the guides would wear excessively and cause a similar issue where the valve would seat off-center and flex and break the valve head off.
This is why Del West offered "free polishing" of the valves to restore the surface finish to an acceptable level.
3) Broken valve springs caused some of the "valve drop" issues as well which made people think that the valve broke when in reality, the spring broke first.
