Aidan's loose oily bunghole actually runs a track lap
#7901
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Look what I found on one of my VVT heads. Look like someone lost a shim at some point. Wonder how long it was run like that.
Also see the interesting wear marks on the shims. Is that normal?
Also see the interesting wear marks on the shims. Is that normal?
#7904
That doesn't look like it spat a shim while running to me, there's nowhere close to enough damage. I managed to lose a shim while replacing valve springs (basically from turning the cam by hand while not having it bolted down all the way) and even that was enough to gouge up the edge of the cam lobe and the bucket noticeably.
The wear pattern on the shims looks like there was dirt in there. How do the cam lobes look?
--Ian
The wear pattern on the shims looks like there was dirt in there. How do the cam lobes look?
--Ian
#7905
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Cam lobes look fine. I can check again.
Can I just flip shims over?
Based on the history of this motor im not overly surprised that its missing. Just annoyed.
Can I just flip shims over?
Based on the history of this motor im not overly surprised that its missing. Just annoyed.
#7906
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Scratches on the remaining shim don't look right, and that thing would be torn up if it was run like that. If I had to guess I'd say I think someone already robbed a shim out of that head.
That sounds like a bad idea but I have no data to back it up.
Also, go buy yourself a tube of Amsoil assembly lube, thank me later.
That sounds like a bad idea but I have no data to back it up.
Also, go buy yourself a tube of Amsoil assembly lube, thank me later.
#7910
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Who, me? ID1k.
I want SUBs simply because with my fancy *** head and aftermarket valves the shims I need are right on the edge of the range offered for the OEM SOBs. Most of the ones in that range are NLA according to Mazda and I've not been able to find a 3rd party supplier. The SUBs are compatible with any number of shims from any number or suppliers and are offered in a HUGE range, and because they don't touch the cam they don't need to go through the same hardening process so they are cheap as ****.
+1 for SUBs. I'll probably be converting some time this winter while the engine is out.
I want SUBs simply because with my fancy *** head and aftermarket valves the shims I need are right on the edge of the range offered for the OEM SOBs. Most of the ones in that range are NLA according to Mazda and I've not been able to find a 3rd party supplier. The SUBs are compatible with any number of shims from any number or suppliers and are offered in a HUGE range, and because they don't touch the cam they don't need to go through the same hardening process so they are cheap as ****.
+1 for SUBs. I'll probably be converting some time this winter while the engine is out.
#7913
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Naw. just id1ks. I do have an oldschool FM secondary fuel rail manifold sitting under my bench though....
thought about sequential flow force. just to annoy you.
My guess is that the motor was running without the shim. No other explanation.
Took apart the other head. Same scratches. Here are pics of the cam too.
And take a look at this. The black spec. It is actually a small hole. Nothing in it, not marks or scaring really. Looks like just a casting hole or something. 2 of the caps had this.
thought about sequential flow force. just to annoy you.
My guess is that the motor was running without the shim. No other explanation.
Took apart the other head. Same scratches. Here are pics of the cam too.
And take a look at this. The black spec. It is actually a small hole. Nothing in it, not marks or scaring really. Looks like just a casting hole or something. 2 of the caps had this.
#7916
So when I spat out a shim during assembly, my cam lobe looked like this (the one on the left):
That's from ONE revolution done at a speed of, oh, I dunno, 10 RPM maybe. If your head had spat a shim while running it would look a hell of a lot worse, if it's missing and nobody's opened the valve cover, then you must have had a visit from the valve shim gnomes.
The cam lobe on the right is the one that had weird wear patterns, which has been suggested to me came from dirt in the motor. I dunno, but I replaced it. The bucket was nicked too, it looked like this:
You couldn't actually get a shim into the bucket afterwards because of the nick. I just filed this one down and it's running fine now.
WTF, Mazda is NLAing the valve shims? That sucks.
--Ian
That's from ONE revolution done at a speed of, oh, I dunno, 10 RPM maybe. If your head had spat a shim while running it would look a hell of a lot worse, if it's missing and nobody's opened the valve cover, then you must have had a visit from the valve shim gnomes.
The cam lobe on the right is the one that had weird wear patterns, which has been suggested to me came from dirt in the motor. I dunno, but I replaced it. The bucket was nicked too, it looked like this:
You couldn't actually get a shim into the bucket afterwards because of the nick. I just filed this one down and it's running fine now.
WTF, Mazda is NLAing the valve shims? That sucks.
--Ian
#7917
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I'm at a loss.
Only thing that could explain it now is that it somehow came out in transport, and then fell out again when the motor was turned over, which is has been a few times.
Maybe its stuck in @turbofans garage, from borrowing the valve cover a few times.
If Mazda really is NLAing shims im definitely going subs.
Only thing that could explain it now is that it somehow came out in transport, and then fell out again when the motor was turned over, which is has been a few times.
Maybe its stuck in @turbofans garage, from borrowing the valve cover a few times.
If Mazda really is NLAing shims im definitely going subs.
#7918
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With how many of these shims are scratched up, and the fact that I can definitely feel the scratches with a fingernail means I'm going subs.
I don't want to deal with buying a whole pile of new shims, and maybe have them not available again.
I don't want to deal with buying a whole pile of new shims, and maybe have them not available again.