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Author Topic: Would You Guys Consider This Excessively Worn?  (Read 1522 times)

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Offline Short Round

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Would You Guys Consider This Excessively Worn?
« on: October 08, 2007, 11:32:42 AM »
Trying to figure out if I should be looking for a replacement head.  Any input would be great.  Thanks...............Chris
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Offline 754

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Re: Would You Guys Consider This Excessively Worn?
« Reply #1 on: October 08, 2007, 11:35:55 AM »
Bolt cam in and check for up and down play with a dial indicator.
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Offline bwaller

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Re: Would You Guys Consider This Excessively Worn?
« Reply #2 on: October 08, 2007, 11:48:16 AM »
As 754 says you can measure, but they don't look all that bad from this seat!
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Offline Short Round

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Re: Would You Guys Consider This Excessively Worn?
« Reply #3 on: October 08, 2007, 12:29:48 PM »
I plan on measuring them but I just want some outside opinions is all
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Offline MRieck

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Re: Would You Guys Consider This Excessively Worn?
« Reply #4 on: October 08, 2007, 01:28:18 PM »
They look OK. It appears someone modified (extended) the cam oil feeds too.
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Offline Bob Wessner

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Re: Would You Guys Consider This Excessively Worn?
« Reply #5 on: October 08, 2007, 02:03:04 PM »
Quote from: MRieck on October 08, 2007, 01:28:18 PM
They look OK. It appears someone modified (extended) the cam oil feeds too.

Wondered about that. I'm not an experienced engine mechanic, but is strikes me that breaking out the edge of the bearing wouldn't be a good thing to do. Wouldn't that prematurely release pressure?
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Offline bwaller

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Re: Would You Guys Consider This Excessively Worn?
« Reply #6 on: October 08, 2007, 02:55:30 PM »
Actually that's the way they come from Honda.
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Offline Bob Wessner

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Re: Would You Guys Consider This Excessively Worn?
« Reply #7 on: October 08, 2007, 04:18:05 PM »
Thanks, learned something today.
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Offline ofreen

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Re: Would You Guys Consider This Excessively Worn?
« Reply #8 on: October 08, 2007, 04:48:49 PM »
From what I see in the pictures, I'd say put it back together and run it.  Out of curiosity, do you know how many miles are on the engine?
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Offline MRieck

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Re: Would You Guys Consider This Excessively Worn?
« Reply #9 on: October 08, 2007, 05:22:08 PM »
Quote from: bwaller on October 08, 2007, 02:55:30 PM
Actually that's the way they come from Honda.
Early heads had just a hole for the 2 inside journals. The later ones were extended. It is tough to tell from the pics but I guess it is a later head.
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Offline Bob Wessner

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Re: Would You Guys Consider This Excessively Worn?
« Reply #10 on: October 08, 2007, 07:34:46 PM »
Remember, no engine experience here, but could someone explain the need for the modification to me? I would have envisioned just a hole. Oil under pressure is forced through it and with nothing else, the only way out for the oil is the bearing surfaces. I can see slight extensions away form the hole, more oil to more surface. But once one of the extensions breaks the edge, isn't a good deal of pressure lost to the bearing surface? ???
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Offline Jonesy

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Re: Would You Guys Consider This Excessively Worn?
« Reply #11 on: October 08, 2007, 07:47:29 PM »
The two outer camshaft end bearings also have a little groove pointing toward the center of the head. The "troughs" between the bearings collect oil up to a predetermined level. Once the oil reaches this level, it spills from the outer troughs into the inner ones, which in turn drain the excess oil back down the cam chain tunnel and back into the sump. The cam lobes get a bath of oil in the troughs with every turn.

As for the pressure loss question, I'll have to dig out my old machine design textbook and see what it has to say...
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Offline Bob Wessner

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Re: Would You Guys Consider This Excessively Worn?
« Reply #12 on: October 09, 2007, 05:39:51 AM »
Maybe it's about time I opened up that spare engine in the garage I've been staring at for three years.
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