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Do you think I might need new valve guides?

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tomj View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Topic: Do you think I might need new valve guides?
    Posted: Oct/16/2020 at 5:14pm
1958? L-head.

I can't believe this engine ran long enough to wear away this much metal. OK the exhaust would just fill the crankcase (understatement) but how did it have any intake vacuum at all?!

Unbelievable. Three of them cracked off a tip where the metal *wore through*.

The thing is, the bores were standard ("0 under") the cyls 3, 4 thousandths of taper (could be more, was a quick check of rusty cylinders). Bearings were shot, looks like water in the oil (grey goo).

The engine arrived disassembled. At first I thought the valves were the wrong ones; too loose in the guides, and a 195.6 OHV valve fit in more than one of the guides!!










The cam profile is so sharp you can almost cut your finger.

Oh boy I wonder how sensible a project this is. They're not very good motors! lol.



1961 roadster american, 195.6 OHV, T5
1968 american, 199ci, T14
AMC pages: http://www.sr-ix.com/AMC/

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Post Options Post Options   Thanks (0) Thanks(0)   Quote wittsend Quote  Post ReplyReply Direct Link To This Post Posted: Oct/16/2020 at 10:12pm
I assume one set idles speed by how tight the valve (side) cover is screwed down? And in Project Farm style, "Can a car idle on oil fumes..., let's find out." Big smile

Just invert the guide to wear on the other side, reinstall and wind string around the valve stem for control. LOL


Edited by wittsend - Oct/16/2020 at 10:19pm
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tomj View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: Oct/16/2020 at 11:58pm
Originally posted by wittsend wittsend wrote:

I assume one set idles speed by how tight the valve (side) cover is screwed down? And in Project Farm style, "Can a car idle on oil fumes..., let's find out." Big smile

Just invert the guide to wear on the other side, reinstall and wind string around the valve stem for control. LOL

I like your thinking! 

Idling on your own oil fumes could re-fill the crankcase too!



With new valve guides costly nearly three dollars fifty, I may consider your excellent scientifical suggestion.

1961 roadster american, 195.6 OHV, T5
1968 american, 199ci, T14
AMC pages: http://www.sr-ix.com/AMC/

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Post Options Post Options   Thanks (0) Thanks(0)   Quote gtoman_us Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2020 at 8:36am
Just a little bit of JB Weld will fix’m like new.
I used to collect trophies, more fun to collect gas receipts and put on miles.

1964 Rambler Ambassador Cross Country Wagon
1965 GTO
1931 Model A


1965 GTO

1931 Model A Ford

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2020 at 7:16pm
That graphite packing rope like used on old spigots
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CR CRUISER Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2020 at 11:44am
A can of STP for the win.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PAGAENT Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2020 at 12:04pm
Is it possible that the valves have 11/32 stems in 3/8 guides? Dr. Faucci probably couldn't explain how the guides could wear like in the pictures.
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tomj View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2020 at 11:38pm
I'm gonna email the guy who gave me the engine. It is a little too much. They're the skinny L-head valves. I have a couple OHV valves. They are identical except for the stem diameter, all are by the book.

It is a mystery how such I thing could run. Could idle, more specifically. 


1961 roadster american, 195.6 OHV, T5
1968 american, 199ci, T14
AMC pages: http://www.sr-ix.com/AMC/

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Post Options Post Options   Thanks (0) Thanks(0)   Quote wittsend Quote  Post ReplyReply Direct Link To This Post Posted: Oct/19/2020 at 11:57am
Maybe the motor had a turbo and the guides are a form of boost control. Sort of an individualized  wastegate. LOL

Seriously though, a flat head would not get the guide side loads that a OHV engine gets from the fulcruming rocker. So it makes the egg shaped guide even more worn that one should think it would have.

My daily drive Mazda has the bucket lifters (should be called plungers being they move downward) and I'd think they go a long way to, one, reducing valve side loads, and two, shielding the guide from excessive oil. Likely that and modern oils allow cars to go 200,000-300,000 miles when given proper care.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: Oct/19/2020 at 11:10pm
yeah, there is actually a lifter pushing up on the valve in the usual way, from the bottom up. There must be more to it than just wear. I just got back from a weekend event and haven't written Andy yet.  
1961 roadster american, 195.6 OHV, T5
1968 american, 199ci, T14
AMC pages: http://www.sr-ix.com/AMC/

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