Compression test results

[Dwd14329]

Unless I missed it, nobody mentioned timing. Is it timed correctly? Especially when you say you "put the distributer back on". Do you know how to adjust the timing? steve

Yes, I timed it according to old way in the manual. Thanks for asking

 

[Dwd14329]

It if starts and runs good then leave it alone.

I never leave my tractor alone unless I think it's running the best it can. The slightest miss bugs the heck out of me. I'm glad I didn't leave it alone because after I removed the exhaust and engine covers I discovered a couple things. My exhaust manifold gaskets were blown and the manifold was pitted on the face side bad enough to have to replace it. This was unseen and obviously a fuel consumption, power, air/fuel mix issue. The valve stems and springs appeared to be in good shape. The gaskets on the engine covers were also leaking oil. So, although the engine was running better after replacing the coil, a little preventative maintenance and inspection was necessary. Don't you think? I haven't even gotten to the govenor yet. Although it appears to be working right, the linkage is sloppy. I'm sure I'll have to address that before I get to a point where I can't run the tractor because the linkage is loose. I guess there is 2 trains of thoughts. Fix it before it gets worse and breaks down or leave it alone until it breaks down in the middle of the field? To each his own. No disrespect.

 

[Factotum]

"Starts and runs good"can be somewhat subjective. When I was looking to buy an 8n I looked at several. Most of the ones I looked at were listed as "runs good" or "runs great". My judgement of that was much different than the sellers. Even the one I ended up getting was listed as "runs great". It is a complete machine that hasn't been gooned too much, and it did indeed run so that was correct. The "great" part was missing though. I had to go through the distributor, adjust the valves, replace and rejet the carb to get it to, what I think is considered "run great". Now it starts immediately, runs smooth, accelerates briskly and idles just around 350-375 rpm without any fuss and will continue to as long as I'm it's caretaker.
Everybody has their tolerance to this kind of stuff, your tolerance may be bit less than someone elses. When I do some maintenance or servicing, I like to get any other problems dealt with before they make me take an unscheduled service break. That's just me. I find that I get to choose when to do the servicing, not the equipment. No offense to anybody who does their service differently. It's their choice.

 

[Dwd14329]

"Starts and runs good"can be somewhat subjective. When I was looking to buy an 8n I looked at several. Most of the ones I looked at were listed as "runs good" or "runs great". My judgement of that was much different than the sellers. Even the one I ended up getting was listed as "runs great". It is a complete machine that hasn't been gooned too much, and it did indeed run so that was correct. The "great" part was missing though. I had to go through the distributor, adjust the valves, replace and rejet the carb to get it to, what I think is considered "run great". Now it starts immediately, runs smooth, accelerates briskly and idles just around 350-375 rpm without any fuss and will continue to as long as I'm it's caretaker.
Everybody has their tolerance to this kind of stuff, your tolerance may be bit less than someone elses. When I do some maintenance or servicing, I like to get any other problems dealt with before they make me take an unscheduled service break. That's just me. I find that I get to choose when to do the servicing, not the equipment. No offense to anybody who does their service differently. It's their choice.

I understand perfectly. When you achieved the 375 rpm idle, was the throttle lever to its lowest point! To start mine, the throttle lever is about 1/4 down. I may have to adjust linkage and govenor, but I haven't gotten to that point yet. I have the manifold and engine covers off waiting for a new manifold. Mine was pitted and the gasket was blown.

 

[Factotum]

I understand perfectly. When you achieved the 375 rpm idle, was the throttle lever to its lowest point! To start mine, the throttle lever is about 1/4 down. I may have to adjust linkage and govenor, but I haven't gotten to that point yet. I have the manifold and engine covers off waiting for a new manifold. Mine was pitted and the gasket was blown.

How I cold start mine- turn on fuel, close battery disconnect, place throttle at first screw, pull choke all the way out, turn over 3 or 4 times, turn on ignition key, turn over again and it starts immediately, adjust choke as needed, usually just let it in, run at this high idle for a couple minutes around 800 or so rpm, turn throttle down as far as it will go and it will idle strong at 375.
To get it to do this reliably, I played with (adjusted) the length of the throttle to governor shaft ( I actually made a new one), it was too short, it was gooned by a previous owner and was all bent up. The position of the throttle lever at the bottom of the steering column shaft needed adjustment, it wouldn't let the throttle go all the way up, probably because the throttle to governor shaft was too short. The tractor ran on the old zenith carb but it had a completely buggered main screw, and couldn't be adjusted. I bought an Amazon carb ( I couldn't get the order page to take a Canadian address here) which I found had too small main and idle jets. The jets were drilled out in steps to achieve good idle and transition to main with the standard adjustment of 1-1/2 turns out main and 1 turn out idle. The rest of the carb was good but needed float tweeking and a good cleanout from machining swarf. I serviced the distributor, making double sure the settings were correct. The timing needed to be set up using a timing light. At first I had problems with this, the centrifugal advance was adding advance erratically because the idle speed was too fast. So there was a bit of back and forth adjusting the carb, timing and adjusting the idle down to where I could get a steady reading of the timing. It was an enjoyable process, I really do enjoy tinkering with equipment trying to get it to operate as good (or better than) the factory intended.

 

[560Dennis]

Curious,Was the engine warmed up to operate temperature before your test ? I might have missed that information

 

[Dwd14329]

Curious,Was the engine warmed up to operate temperature before your test ? I might have missed that information

No, it wouldn't run enough to get it warm. That's why I ran the test. I thought I might have a stuck valve. Although, compression readings were on lower end, I don't believe I conducted test accurately. Learned alot on this thread. Once I learned I did not have a stuck valve, I reverted back to other options. I read many threads on my issue and one stuck out as a possibility. New coil may be faulty! So, I bought a new quality coil, not from Amazon, and low and behold, she fired right up! That's really bothers me, ohmed out the first one and it was good but it wasn't! That one was new too. Anyway, I did remove engine covers and manifold, inspected valves and stems, checked clearance and they were in spec. The manifold gasket was blown and the engine cover gaskets leaked. The manifold was pitted on the face bad enough that I had to order another new one plus gaskets. I also ordered a quality carberator, not from Amazon. I plan to get good use out of this tractor and its worth spending extra dollars for quality parts. My parts are due today and I plan to install and get this baby up and running. I anticipate smooth running machine once I dial in carb and govenor settings. Sorry for the short story but I thought you might want to know my train of thought.

 

[Dwd14329]

How I cold start mine- turn on fuel, close battery disconnect, place throttle at first screw, pull choke all the way out, turn over 3 or 4 times, turn on ignition key, turn over again and it starts immediately, adjust choke as needed, usually just let it in, run at this high idle for a couple minutes around 800 or so rpm, turn throttle down as far as it will go and it will idle strong at 375.
To get it to do this reliably, I played with (adjusted) the length of the throttle to governor shaft ( I actually made a new one), it was too short, it was gooned by a previous owner and was all bent up. The position of the throttle lever at the bottom of the steering column shaft needed adjustment, it wouldn't let the throttle go all the way up, probably because the throttle to governor shaft was too short. The tractor ran on the old zenith carb but it had a completely buggered main screw, and couldn't be adjusted. I bought an Amazon carb ( I couldn't get the order page to take a Canadian address here) which I found had too small main and idle jets. The jets were drilled out in steps to achieve good idle and transition to main with the standard adjustment of 1-1/2 turns out main and 1 turn out idle. The rest of the carb was good but needed float tweeking and a good cleanout from machining swarf. I serviced the distributor, making double sure the settings were correct. The timing needed to be set up using a timing light. At first I had problems with this, the centrifugal advance was adding advance erratically because the idle speed was too fast. So there was a bit of back and forth adjusting the carb, timing and adjusting the idle down to where I could get a steady reading of the timing. It was an enjoyable process, I really do enjoy tinkering with equipment trying to get it to operate as good (or better than) the factory intended.

Factotum, I was told on this forum a timing light couldn't be used because absence of harmonic balancer on thd 4 cyl flathead. What type of timing light do you use and how? I did check timing per the manual method, it was correct as far as I could see. I'm interested in a timing light method.

 

[Factotum]

The brand of my timing light is Actron. Unless the 2n ( which I am unfamiliar) doesn't have timing marks on the flywheel any timing light should work. On the 8n there is a hole on the side of the clutch flywheel area. I don't know if the 2n has this provision. I read on another thread someone was having a hard time trying to time an original front distributor tractor with a side distributor engine transplanted in. My particular timing light has options for 2cyl, 4 cyl and rpm. It also is 12v which doesn't work on my tractor, but a spare 12v battery powered it up and I was able to use it normally.

 

[Dwd14329]

The brand of my timing light is Actron. Unless the 2n ( which I am unfamiliar) doesn't have timing marks on the flywheel any timing light should work. On the 8n there is a hole on the side of the clutch flywheel area. I don't know if the 2n has this provision. I read on another thread someone was having a hard time trying to time an original front distributor tractor with a side distributor engine transplanted in. My particular timing light has options for 2cyl, 4 cyl and rpm. It also is 12v which doesn't work on my tractor, but a spare 12v battery powered it up and I was able to use it normally.

I believe that was the issue, no timing marks. Thanks

 

[Brown David]

I believe that was the issue, no timing marks. Thanks

That would be the only reason you couldn't use a timing light.

Timing marks could be created if one was so inclined but would hardly be worth the effort IMO.

 

[ASEguy]

My results for compression test is as follows: firing order 1423
1947 Ford 2N

#1 cylinder 94 psi
#2 cylinder 81 psi
#3 cylinder 89 psi
#4 cylinder 83 psi

Can you or any mechanic see any red flags with these results? Please advise.

A general rule is 10% of rated and 10% of each other. Pressures are affected by heat (operating temperature is best for proper sealing), throttle opening and cranking speed