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  #1   IP: 198.243.20.242
Old 02-23-2020, 08:00 PM
to alaska! to alaska! is offline
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Valve guides came out while removing stuck valve

I'm fixing up my Atomic 4 that's in my 1975 Newport 30.

What I hoped would be a straightforward job has turned into something a bit more exciting.

For two out of four stuck valves, the valve guide has come out with the valve!



I'm not really sure where to go from here. I could try to remove the valve guide from the valve, but that seems unlikely to happen without damage. Otherwise, can someone give me an overview of how to install a new valve guide and valve? I wasn't able to find a thread for this, but feel free to send me a link if I missed it.
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  #2   IP: 155.186.124.219
Old 02-24-2020, 10:57 AM
Dave Neptune Dave Neptune is online now
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It is not often that guides will fail unless poorly installed. Either the quide was reamed to big or the guide was to small. These are pressed in and in some cases a heat shrink is applied.

Now you will need to find a larger guide by a few thousandths of an inch or next size up if available.

The valve sticking to the guide is rust from water and/or to little clearance. And that looks to be an exhaust valve which should of had more clearance than the intakes to start with.

You will need to look around for what is available "guide size" wise and hopefully find something to fit.

I have never been a big fan of replacing guides in a flat head unless the valves were almost rattling in the hole. A flathead does not require the valve sealing like an overhead engine. In an overhead the oil can't fight gravity and is always being pulled "down" the valve to get to the combustion chamber where gravity helps to keep the flathead valves oil draining back to the pan.

Dave Neptune
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  #3   IP: 155.186.124.219
Old 02-24-2020, 10:59 AM
Dave Neptune Dave Neptune is online now
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Oops, just noticed your a newbie so a big Afourian welcome to ya!

Dave Neptune
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  #4   IP: 198.243.20.242
Old 02-24-2020, 02:30 PM
to alaska! to alaska! is offline
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Thanks for the kind welcome! I have replaced valves before, but this is my first time replacing valve guides, so I'm a little lost.

To clarify, when you say I need a larger guide, what exactly does that mean? Are you saying I need a guide with a slightly larger outer diameter (to keep the guide in place, inasmuch as the old one has come out with the valve...)?

Your reply makes it sound like just buying a new valve and valve guide from Moyer won't be sufficient? Any clarification on this would be helpful - I still have a lot to learn!

Finally, it seems like the only right way to install a valve guide is with a press. Inasmuch as my engine is in my boat, and I only have ~5 inches of clearance above my engine, is this the point where I need to pull the engine in order to install the valve guide? This is something that I'd like to avoid, but can if necessary.

Last edited by to alaska!; 02-24-2020 at 02:53 PM.
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  #5   IP: 32.211.28.40
Old 02-24-2020, 07:05 PM
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Al Schober Al Schober is offline
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The fit of a new guide into the block isn't a matter of .001"s, it's more like you'll be dealing in .0001"s. Taking a measurement then telling a shop to grind a guide to a particular size is a disaster waiting to happen - even if you give them your micrometer!
If I were running a shop and you came to me, I'd ask you to bring me the block. Then I could measure the holes using my tool and my gauges. The holes for the guides may need reaming before the new guides are installed. And I probably wouldn't need a press to install the new guide - I'd just pack it in dry ice for a while, then just slide it in.
Recommend you contact the folks at goodson.com for suggestions. In addition to making parts, they also make the tooling for engine work. They just might have a suggestion that would save the day.
Keep in mind that once the new guide is in place, it will need to be reamed to size to fit the new valve stem. As I recall, the A4 spec clearance for stem to guide changed over the years, becoming somewhat looser.
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  #6   IP: 198.243.20.242
Old 02-24-2020, 11:10 PM
to alaska! to alaska! is offline
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Al, thanks for the suggestions. I'm starting to get a better idea of what this job will take. I'll reach out to Goodson's and see if they have any advice!
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