8N Stuck Exhaust Valve

steelwheeljim · Jun 19, 2020

I'm working on a 48' 8N. All of the exhaust valves were stuck open. I removed the head and gently tapped on the valves after soaking them in penetrating oil. I got 3 loose with one being stubborn. When i continue to tap on the fourth valve, i am forcing the entire valve guide down and the valve is not coming loose. If i turn the motor over by hand, it forces the guide back up.

Should i continue to soak the valve with penetrating oil and keep tapping on it, or pull the guide from the block and free it up that way? I really didn't want to get into it this far and removing internal parts. Suggestions please!

rew1953 · Jun 19, 2020

Use a 50/50 mixture of Acetone and ATF as penetrating oil. Resoak for 2-3 days and it should free up.

HarryVanderpool · Jun 19, 2020

How long has it been since your 8n had a valve job?
I just want to encourage you to take the leap and renew your valve train. You may be amazed at the results.
After running the daylights out of my 2N for 33 years, I decided to do the valves last winter.
I ordered the Neway 3 angle valve set cutter tools, and the entire valve train. That's right; I removed the valves, springs, clips, guides and threw them in the recycle bin.
Very, very carefully, cut the valve seats to specification and installed everything new.
WOW!!!
What a difference!!! The old 2N has WAY more snap and grunt.
Purrs like a kitten.
And no; "Lapping the valves" is not a good option. In fact it is a very poor option.
Give your N a precision valve job, a complete tune-up and whatever else it may need and you will be amazed!
Do it, do it, do it!!!

TheOldHokie · Jun 19, 2020

(quoted from post at 22:11:53 06/19/20) I'm working on a 48' 8N. All of the exhaust valves were stuck open. I removed the head and gently tapped on the valves after soaking them in penetrating oil. I got 3 loose with one being stubborn. When i continue to tap on the fourth valve, i am forcing the entire valve guide down and the valve is not coming loose. If i turn the motor over by hand, it forces the guide back up.

Should i continue to soak the valve with penetrating oil and keep tapping on it, or pull the guide from the block and free it up that way? I really didn't want to get into it this far and removing internal parts. Suggestions please!

You have already expended way more time and effort tha it takes to remove the valve and guide to clean it properly. Based on your description the keeper is missing and the assembly is already loose in the block - pull it out the top and fix it. Nothing at all complicated in that process.

TOH

8N Stuck Exhaust Valve

steelwheeljim

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rew1953

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HarryVanderpool

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TheOldHokie

Well-known Member

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