Valve guide wear
Thread Starter
TECH Addict
Joined: Nov 2005
Posts: 2,379
Likes: 2
Valve guide wear I recently went all LS3 top end due to my (now defunct) Patriot Performance Stage 2.5 5.3 heads developing excessive valve guide wear.
I ran scorpion 1.7 roller rockers on them for a number of years then developed a lifter failure (LS7 lifters). In the weeks prior to my lifter failure, I noticed that getting hard on it had some smoke come out the back. TBH I've always had a small "puff" of smoke come out on dyno runs, then on subsequent runs, it cleaned up. It just got worse over time.
I am aware of some issues between soft/hard bronzed guides and the infamous LS7 guide issues, but for most aftermarket heads, how necessary is roller rockers? Even despite using rollers, I still developed serious wear across ALL guides. Preload and geometry were correct. Are we pretty much in a buyer beware situation? I mean we have to trust that every vendor/aftermarket head group doesn't cheap out on us with valve guides.
Knowing what I know now, I should have been very concerned about getting any significant smoking since day 1 of those heads.
I ran scorpion 1.7 roller rockers on them for a number of years then developed a lifter failure (LS7 lifters). In the weeks prior to my lifter failure, I noticed that getting hard on it had some smoke come out the back. TBH I've always had a small "puff" of smoke come out on dyno runs, then on subsequent runs, it cleaned up. It just got worse over time.
I am aware of some issues between soft/hard bronzed guides and the infamous LS7 guide issues, but for most aftermarket heads, how necessary is roller rockers? Even despite using rollers, I still developed serious wear across ALL guides. Preload and geometry were correct. Are we pretty much in a buyer beware situation? I mean we have to trust that every vendor/aftermarket head group doesn't cheap out on us with valve guides.
Knowing what I know now, I should have been very concerned about getting any significant smoking since day 1 of those heads.
Patriot cheaped out on a lot of things. But, it sounds like they used bronze guides?
If your wipe pattern was not VERY narrow with the Scorpions, then yes, I could see valve guide wear with any bronze guide, cheap or not. But generally, bronze wears slowly once the wear begins.
But if you had a lifter issue, then you may have had some pushrod flex in there due to ramp rates, valvetrain weight, or lack of spring pressure (which is a known issue with Patriot Golds over time) or some combination. If the springs weakened over time, then you certainly could have lost some of the valvetrain geometry as slack was introduced into the system and could have lead to additional wear. So the guides, lifters, etc took a beating with the "play" of the valvetrain system.
The point is, you have to regularly inspect wear items in the valvetrain, like the springs and guides, to gauge how they are aging.
If your wipe pattern was not VERY narrow with the Scorpions, then yes, I could see valve guide wear with any bronze guide, cheap or not. But generally, bronze wears slowly once the wear begins.
But if you had a lifter issue, then you may have had some pushrod flex in there due to ramp rates, valvetrain weight, or lack of spring pressure (which is a known issue with Patriot Golds over time) or some combination. If the springs weakened over time, then you certainly could have lost some of the valvetrain geometry as slack was introduced into the system and could have lead to additional wear. So the guides, lifters, etc took a beating with the "play" of the valvetrain system.
The point is, you have to regularly inspect wear items in the valvetrain, like the springs and guides, to gauge how they are aging.
Thread Starter
TECH Addict
Joined: Nov 2005
Posts: 2,379
Likes: 2
I checked the wipe using the marker method. It was quite narrow.
Geometry measuered out fine. Made good power up top, no abnormalities except for the "smoke" on WOT since the heads were put in. The lifter issue was a one off thing of 1 lifter. Just a run of bad luck there.
With the LS3 heads now, I've got nice smooth power delivery to 6200 rpm. no abnormalities or float issues indicated on dyno. Since I had been burning oil for awhile with the previous heads, I've had to wait for my exhaust to "clean" up naturally. These days its nice to get on it hard and not see a trace of "smoke". This also seems to be keeping my oil clean too... damn exhaust valve guides was bleeding exhaust gasses into my engine....
Geometry measuered out fine. Made good power up top, no abnormalities except for the "smoke" on WOT since the heads were put in. The lifter issue was a one off thing of 1 lifter. Just a run of bad luck there.
With the LS3 heads now, I've got nice smooth power delivery to 6200 rpm. no abnormalities or float issues indicated on dyno. Since I had been burning oil for awhile with the previous heads, I've had to wait for my exhaust to "clean" up naturally. These days its nice to get on it hard and not see a trace of "smoke". This also seems to be keeping my oil clean too... damn exhaust valve guides was bleeding exhaust gasses into my engine....
