8N engine knock

Ok, here is the problem. I have an 8N I just completely rebuilt the engine on. This includes timing gear, bearings, mains, oil pump, sleeves etc.
It starts right up and runs fine except at high RPM's and it has this real loud knock at the rear of the engine. It seems to be coming from the bell housing and maybe the flywheel? It only knocks at very high rpms and that is a mystery to cause if it was a rod, it would knock all the time?
I never heard this tractor run before I bought it cause it had a bad timing gear. Previous owner used long bolt on governor and it stripped the timing gear. That is why I decided to overhaul the whole thing while I was at it.
Anyway, any and all help is appreciated.
 
Hotdawg1984 ,If you think it is coming from the flywheel area you might consider if it may have 1 flywheel bolt a little to long.Or maybe the condition and end play in the thrust on the main bearing causing the crank to move forward and back.
 
Yes, rods are predictable, in rhythm and load sensitive. I'm assuming this knock isn't under load, in neutral, and without pump operation? How is your oil pressure?
 
(quoted from post at 18:13:30 10/12/16) My hydraulic pump knocks. Does it stop if the clutch is in?

No, with clutch in it still knocks. I was able to pinpoint it at the bell housing area by using the old broom handle method. It could be # 4 piston slapping but why?
 
No load as I still have hood off. Oil pressure is 15 to 25 lbs depending on rpm's. It is not a rattle but a good solid knock. Had a Dodge six one time that had a rod turned wrong and it had a solid knock under load. Took a teardown to find. Back in the 50's the dodge six rods had an offset of about 1/16th of an inch and if installed wrong it tore the crank a new one.
 

While that oil pressure is not alarmingly low on a well broke in engine, I would expect for a fresh engine that it would be higher than that. Somewhere north of 35-40 PSI idling cold.
 
(quoted from post at 05:06:29 10/13/16)
While that oil pressure is not alarmingly low on a well broke in engine, I would expect for a fresh engine that it would be higher than that. Somewhere north of 35-40 PSI idling cold.

You are right about that and have had the same issue in past with these foreign mad gauges. They are not accurate at all. I have not tested the pressure with one of my good gauges but will at some point in time.
Right now I am leaning towards something wrong with the rear main. Could be the oil hole plugged, so today I will tear it down again and re-inspect everything. Will also replace that oil pump just in case.
Thanks to all. I will let you know what the cause was.
 
(quoted from post at 08:19:40 10/13/16)
(quoted from post at 05:06:29 10/13/16)
While that oil pressure is not alarmingly low on a well broke in engine, I would expect for a fresh engine that it would be higher than that. Somewhere north of 35-40 PSI idling cold.

You are right about that and have had the same issue in past with these foreign mad gauges. They are not accurate at all. I have not tested the pressure with one of my good gauges but will at some point in time.
Right now I am leaning towards something wrong with the rear main. Could be the oil hole plugged, so today I will tear it down again and re-inspect everything. Will also replace that oil pump just in case.
Thanks to all. I will let you know what the cause was.

You do realize it's not just a simple swap to "replace" the oil pump on that engine don't you?

TOH
 
(quoted from post at 07:09:06 10/13/16) Could the flywheel be loose???

Zane

OK. Tore the engine down again and discovered the crank oil ports were clogged with "stuff". Could have been dirt dobbers at work the one week between installing the mains and finishing the job.
Also discovered the bolts holding on the flywheel MAY be loose and/or too long as well.
Have attached 3 pics of the "short" or loose bolts and 1 pic of the one that appears to be too long and rubbing on the back of the engine. So there are 2 that appear to be short or loose and 2 the appear to be too long and rubbing.
Next I will pull the engine and see for sure what the situation is and then I will put in the throw out bearing, clutch and clutch plate and change out those flywheel bolts and pilot bearing.
 
OK, no pics cause I can not get them to appear here. Hit upload button and nothing. Maybe some one can tell me what I am doing wrong.
 

iirc, the option under "advanced posting tools" is non-functional. use the section below that: "upload photos/videos".

and be sure to follow the listed guidelines:

Upload one or more videos to your post. Photo filesizes should be less than 300K and Videos, less than 2MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
 

ps: it just occurred to me that the option i described is in modern view, and i have no idea what does or doesn't do what in classic view.
 
(quoted from post at 11:45:41 10/13/16)
ps: it just occurred to me that the option i described is in modern view, and i have no idea what does or doesn't do what in classic view.
I tried both features/options and neither one works , thanks anyway.
 
(quoted from post at 16:52:01 10/13/16)
(quoted from post at 11:45:41 10/13/16)
ps: it just occurred to me that the option i described is in modern view, and i have no idea what does or doesn't do what in classic view.
I tried both features/options and neither one works , thanks anyway.

Upload the files to a picture hosting site. Then use the IMG button at the top of the new message dialog box to inert them in your message.

TOH
 
(quoted from post at 16:52:01 10/13/16)
(quoted from post at 11:45:41 10/13/16)
ps: it just occurred to me that the option i described is in modern view, and i have no idea what does or doesn't do what in classic view.
I tried both features/options and neither one works , thanks anyway.
Under advanced posting tools, click upload photo, click choose file,
browse for your picture, once selected click upload.
Then wait for it to appear in the little preview square.
Once it does, there will be a "continue" button above it. Click continue.
You will see the image code added below what you are typing. (see pics for what that looks like)

You can then click Preview to see what it looks like before clicking submit.

41409.jpg


41410.jpg


41411.jpg
 

ps: should add, it does work here too. maybe next time i'll test it before i post.

or not :lol:
 
"some senile person may have remembered things backwards"

I liked it better when that button worked, less steps!
That stopped working for me some time ago but I haven't tried it lately.
 
(quoted from post at 13:52:01 10/13/16)
(quoted from post at 11:45:41 10/13/16)
ps: it just occurred to me that the option i described is in modern view, and i have no idea what does or doesn't do what in classic view.
I tried both features/options and neither one works , thanks anyway.
Ok, thanks. I will try that next time.
In the meantime I got the engine apart and flywheel off and good thing as the clutch is bad and needs replacing.
Also discovered that the oil supply tube that runs the length of the engine is partially plugged and will need to hot tank the engine.
The motor was run for less than 5 minutes but it wiped out the new bearings and the crank has no damage , or so it appears. Machine shop will do the analysis.
Thanks to all.
 

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