460 head help
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New User
Joined: Mar 2004
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From: prince edward island
460 head help
in need of rocker nuts for 460 dovec nonadjustable 68 lincoln.
thx please tell me where to find parts for this old of model
kendallbuell@htomail.com
thx please tell me where to find parts for this old of model
kendallbuell@htomail.com
Elder User
Joined: Jan 2004
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Step one - ditch the cast iron rockers you currently have.
Step two - go to your local parts house or speed shop and get a set of rocker arms and studs for a BB Chevy. They will screw in with no mods. Viola! Instant adjustable rocker arm setup that's much stronger than the cast stockers.
Why the BB Chevy pieces? Because the BB Chevy pieces are relatively inexpensive and you can find them almost anywhere.
Brad
Step two - go to your local parts house or speed shop and get a set of rocker arms and studs for a BB Chevy. They will screw in with no mods. Viola! Instant adjustable rocker arm setup that's much stronger than the cast stockers.
Why the BB Chevy pieces? Because the BB Chevy pieces are relatively inexpensive and you can find them almost anywhere.
Brad
Elder User
Joined: Jul 1999
Posts: 877
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From: Missouri
It's not guite that easy if you want the guides to last. The stud bosses do need to be milled off and the pushrod length checked to keep the geometry correct. I tried the just bolt it all on and go several years ago and it didn't work as the guides wore out very quick.
As for new nuts you can put a set of Crane Koolnuts on the studs you have for about $30 and you will be able to adjust the valves also.
As for new nuts you can put a set of Crane Koolnuts on the studs you have for about $30 and you will be able to adjust the valves also.
Elder User
Joined: Jan 2004
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If you're talking about the valve guides, they shouldn't have worn abnormally at all if the lifter preload was set correctly. If you're talking about the pushrod guides then I should ask if you made sure to get the right diameter pushrods.
Brad
Brad
Last edited by Brad Johnson; Oct 1, 2004 at 01:05 PM.
Elder User
Joined: Jul 1999
Posts: 877
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From: Missouri
Lifter preload has no effect on valve guides. The guides wear out because the geometry of the rocker arm is wrong and it puts side pressure on the valve instead of straight down. When you just bolt on a set of guideplates without machining the pedestal you raise the rocker arm the thickness of the guideplate, usually about .200. That makes the rocker arm only use the outside edge of the valve stem and put side pressure on the valve. This is why I said you need to check the pushrod length so that the rocker uses the whole surface of the valvestem.
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I guess I'm missing something. Presuming no other changes you shouldn't have to machine the pedestal to maintain proper geometry unless you run out of threads on the stud. Using the stock length pushrods, the installed height of the rocker should remain the same as stock as long as you have enough threads on the stud to compensate for the thickness of the guide plate (typically around 0.100-0.125). The only thing I can think of that should affect guide wear or valve stem tip wear would be an off-center rocker tip from a misaligned pushrod guide slot or a change in relative location due to rocker ratio (improper rocker tip length).
If you are building a new engine, then it's a moot point. When new valves are installed they will have to be cut to the right hight or you will have to get new pushrods of the right length to maintain rocker placement on the valve stem tip.
By the way, I'm presuming from your answer that your abnormal wear was valve guides and not pushrod guides. Correct?
Brad
If you are building a new engine, then it's a moot point. When new valves are installed they will have to be cut to the right hight or you will have to get new pushrods of the right length to maintain rocker placement on the valve stem tip.
By the way, I'm presuming from your answer that your abnormal wear was valve guides and not pushrod guides. Correct?
Brad
Last edited by Brad Johnson; Oct 1, 2004 at 03:13 PM.
