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Subject: Possible valve noise

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Tlawing    Posted 09-06-2020 at 12:03:30 [URL] [DELETE]        [Reply] [Email]  
  • Possible valve noise
  • I have been working on an 8n that had been setting for 6 or7 years. Replaced Battery, coil, plugs, points, condenser, rotary button, dist cap, plug wires. Intake Tapets were sticking on cyl 1& 2. Got them freed up through side panel. Hydraulics would not lift. Valve was sticking in pump, got it freed up, changed transmission fluid (seems to be working fine). Changed oil and filter.
    While running it lost oil pressure and head a screetch. Engine was not locked up. Put oil in oil canister got oil pressure back. Itís around 40 psi. When hot it drops to around 20 or a little below. The problem: sounds like a valve chattering. Compression test show about 70 on cyl, 90 on 2 & 3 and around 70 on 4. Compression test seems to indicate good rings. It does seem to indicate valve sticking. But they look like they are moving free. It does have adj valves. Does it sound like valve adj or something else? Thanks

    Bruce(OR)    Posted 09-06-2020 at 16:58:11 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Possible valve noise
  • Comp check indicates sticking valves?
    Uh, okay.
    That comp check, was it hot or cold? Open or closed throttle?
    12V or 6V?
    Same number of rotations for each cylinder? Rechecked it?
    Wet or dry?
    Changed how much on the wet test? up, down?
    Did you use a jumper battery to keep the cranking spped the same all the time or is your battery good enough not to drop with extended cranking?

    Tlawing    Posted 09-06-2020 at 18:18:26 [URL] [DELETE]        [Reply] [Email]  
  • Re: Possible valve noise
  • Battery had full charge from battery charger for test. Iím not a mechanic. Iím going by the documentation with the compression checking tool. Itís been a couple of weeks since I checked it. The best I can remember the compression didnít move gauge a couple of times then it went to 70. Documentation indicated sticking valves. Not being a mechanic I need you to explain the wet and dry test. It has been converted to 12v. It was the same rotations for each cyl.
    It does sound like its coming from the valve area. The check was done cold. The throttle was open.
    Iím not sure how many years it was outside uncovered in the elements. It was my fatherís, he passed away in February after a 6 or 7 year sickness. So it has been that many years at least without being used.
    Again I am not a mechanic, just trying to get it running again. Most repairs have been done because something was either obvious or from research on these boards. This is the first time Iíve posted to any of the boards. If Iím not answering something please ask.
    Thanks for any and all help.

    Bruce(OR)    Posted 09-06-2020 at 21:17:21 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Possible valve noise
  • Not a mechanic can be a good thing. Your brain doesn't overwork itself and you pass up the obvious.
    You did a dry cold test. The numbers you have indicate enough "umph" to make it fire.
    Warm engine will bring the numbers up, a wet test is simply adding about a tablespoon of oil to the cylinders and that helps to seal the rings and raise the comp numbers.
    A good engine will see very little rise in the comp numbers on a warm engine. A cold engine should raise them higher. A worn engine can see a 20 PSI increase in comp numbers. Generally that is also accompanied by smoke while running due to the rings/cylinder being worn out.
    Your flat head engine has the valves in the block and adding oil into the plug holes should help those to seal also.
    Generally weak valves can be found with a fluctuating vacuum gauge. Hooking up a vacuum gauge to your engine might be possible IF your manifold has a screw in the side of it for utilizing a vacuum operated milking machine.
    Chances are you have no screw or it is absolutely frozen in the manifold.
    Valves during a comp check are either open or closed.
    Open valves will not build compression.
    Your first post sounded like you got it running. Now it appears to not be running.
    Valve adjustment is for the valve to spend enough time seated to dissipate the heat during engine operation. A tight valve will not stay seated long enough to dissipate heat and will burn the edges of the valve soon enough.
    A loose valve will do a good job of dissipating heat but will be noisy in the process and the engine performance will suffer due to the valve not fully opening.
    So, is it running or not?

    Tlawing    Posted 09-07-2020 at 00:29:36 [URL] [DELETE]        [Reply] [Email]  
  • Re: Possible valve noise
  • Yes it is running. Fires right up. Itís just the noise that I was concerned with. I have used it to push trees that have been cut down. I run it for 10 to 20 min then let it cool down. With it having set so long I didnít want to run it to much. I thought of it more like a break in period.
    I have put a capful of marvel mystery oil in cyl 1 and 4 and let it set for hours. The noise is less now than it was. I have started it every day and let it run, hoping to keep everything lubricated. It rained for 2 days and I could not start it. The next day the noise was worse. By running it daily the noise decreases. Based on your description it sounds like a loose valve.
    It seems to have good power, but at times it sounds almost like itís going to back fire but it doesnít. Maybe that is associated with the noise, or maybe a clue. Other than the chatter, everything else seems to work fine.
    Thank you again for taking the time to help.

    Bruce(OR)    Posted 09-07-2020 at 07:23:49 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Possible valve noise
  • Chatter could be a bunch of things. A stethoscope might come in handy. You can make your with a bout a 4 foot piece of 3/8 inch fuel hose. Fire it up and one end to your ear, the other all over the engine. Side plate, water pump, generator, etc.
    Oh yeah, the fan belt is turning watch your hands.
    You said your valves were adjustable, might be your problem...
    Then again could be...?
    Hopefully a far more intelligent person than I chimes in shortly on how to adjust your valves.

    Tlawing    Posted 09-07-2020 at 11:03:31 [URL] [DELETE]        [Reply] [Email]  
  • Re: Possible valve noise
  • Thanks for your reply. I have used a 4ft dowel rod. I can not tell for sure. At first I thought it was coming from the starter area. I took the starter off - everything seemed fine. Then I thought it was in the valve area. It could be transferring from anywhere. Thank you again for your help.

    Bruce(OR)    Posted 09-07-2020 at 14:53:20 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Possible valve noise
  • Starter usually doesn't move when the engine is running. If it does, you have bigger problems. I would have to drop an ear on the side cover front to rear.
    Last I knew about adjusting those valves was using a special tool to hold part of it from rotating. Got a manual?
    Might be time to open it and give them a twist and see what happens with an adjustment. I haven't gotten my hearing aids yet, even though they are free to me, just call it a combination of old man lazy vanity in any order. So hearing your engine from here might be a bit more difficult than usual.

    Tlawing    Posted 09-07-2020 at 16:23:51 [URL] [DELETE]        [Reply] [Email]  
  • Re: Possible valve noise
  • I didnít think it was the starter when I took it out to check. Stater was fine. The noise I believe is coming from the 4th cyl valve area. I have read the adj procedure in the manual. I donít have the tool. I believe I can use a punch through the hole to hold it. It also shows a 7/16 wrench that has been ground off at the tips and cut to 5 inches. I have ordered a thin wrench that should be here in a few days. I will give it a try.
    As far as hearing I have trouble hearing anything. I say I canít hear you all day.
    Thanks again for your help.

    Bruce(OR)    Posted 09-10-2020 at 17:39:13 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Possible valve noise
  • Glad to help out. Surprised no one else has chimed in with vastly more experience.
    Was off the web for the past day due to power loss from high winds knocking down trees and power lines. Today the sky is smoke filled and I pray no one does anything silly and start another fire. Mean while I have projects lined up and it doesn't help I ran the acy torch over my left hand. 2nd degree burn is fun.
    You sure you desire to listen to someone as smart as I am?

    Tlawing    Posted 09-11-2020 at 20:05:39 [URL] [DELETE]        [Reply] [Email]  
  • Re: Possible valve noise
  • Sorry to hear that. Hope your burns are not too painful. Glad you have power back on. I have not had time to check forum this week. Had 2 different dr.ís appts. (Had a couple of heart attacks in the past, stroke and colon removed.). This was a few years ago. Now it seems like I stay in dr.ís offices.
    I am ALMOST convinced itís the 4th exhaust valve making the noise. I have new gaskets. As soon as I can get the time Iím going to take exhaust manifold off so I can get to the valves easier. That way I can get a good look at all of them.
    Thanks again. I will also be praying for you to have less pain and heal quickly.

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