1952 8n Blowby?

Hello,

I have an 8n that seems to run pretty good. It had set for a couple of years before i acquired the tractor. It doesn't smoke out the exhaust and holds 40 lbs oil pressure at working speed and 20 at hot idle. The tractor seems to have decent power, but I don't have any experience with them.

However, it does have a white vapor-like smoke coming out of the crankcase vent when it is running. It doesn't puff out, it just seems to be rising out of the vent when the cap is off. It is not very much smoke at all, but it is there.

I changed the oil on it yesterday and cleaned quite a bit of what seemed like clear water off of the tab that keeps the oil from splashing out. Ran it for about an hour after the oil change and the clear water was back as much as before.

Is this condensation in the crankcase? I was thinking this could be causing the smoke, but the smoke quits as soon as you kill the engine so that leads me to believe it is blowby.

What do you guys think? If it is blowby and it is slight does it have much life left in it? I have no idea how long they generally run once they start this before you absolutely have to rebuild them. I had planned on finish mowing 50-100 hours a year with this tractor.

Thanks.

"Is this condensation in the crankcase?"

Very possible. Since you say it has been setting a while,
I would run it and really work it, then see what it does.
Your OP seems Ok and no smoke, that's a plus.
I've seen some real skeeter foggers run for a long time
so a little blowby wouldn't worry me too much.

(quoted from post at 14:02:08 12/27/14) Hello,

I have an 8n that seems to run pretty good. It had set for a couple of years before i acquired the tractor. It doesn't smoke out the exhaust and holds 40 lbs oil pressure at working speed and 20 at hot idle. The tractor seems to have decent power, but I don't have any experience with them.

However, it does have a white vapor-like smoke coming out of the crankcase vent when it is running. It doesn't puff out, it just seems to be rising out of the vent when the cap is off. It is not very much smoke at all, but it is there.

I changed the oil on it yesterday and cleaned quite a bit of what seemed like clear water off of the tab that keeps the oil from splashing out. Ran it for about an hour after the oil change and the clear water was back as much as before.

Is this condensation in the crankcase? I was thinking this could be causing the smoke, but the smoke quits as soon as you kill the engine so that leads me to believe it is blowby.

What do you guys think? If it is blowby and it is slight does it have much life left in it? I have no idea how long they generally run once they start this before you absolutely have to rebuild them. I had planned on finish mowing 50-100 hours a year with this tractor.

Thanks.

Click to expand...

Flipside, Its probably condensation in the crankcase.Question does it have a thermostat in working order in the upper radiator hose? Check to see if its there and working properly. If not that will cause condensation to build up in the crankcase and not evaporate by not letting engine get up to temperature.

Thanks for the replies. I will check the thermostat. I know it has one in there because I can feel it in the hose, but it could be stuck open now that you mention that. The radiator cap doesn't even get warm when it is up to operating temp. I'm not sure if that is normal or not.

I was thinking of spending the $20 on a 180 thermostat even before this. If the thermostat in there is stuck open I'll need a new one anyway.

Do most guys on here like the 180? Seems like I read that they run a little better hotter and it is better for the oil.

Flipside,Yeh,If I was replacing one it would be a 180%.That will help your condensation problem to.

Thanks for the replies. I will check the thermostat. I know it has one in there because I can feel it in the hose, but it could be stuck open now that you mention that. The radiator cap doesn't even get warm when it is up to operating temp. I'm not sure if that is normal or not.

I was thinking of spending the $20 on a 180 thermostat even before this. If the thermostat in there is stuck open I'll need a new one anyway.

Do most guys on here like the 180? Seems like I read that they run a little better hotter and it is better for the oil.

On my OHV the "crankcase ventilation" air enters the crankcase via the valve cover, goes down the push rod holes in the head, to the crankcase and exits at the oil filler pipe cap . . . so,
ensuring that there is unrestricted air flow is sometimes overlooked.

I don't know about your flathead.
Is there an crankcase air intake port?

T

My 9N blows smoke out the tailpipe and the oil filler but it runs well and doesn't foul plugs. The blowby is more of an annoyance, causing smelly clothes and requiring frequent oil fills.

Probably is just condensation. If you ever put a temperature gauge
on one you be amazed at how cold these engines will run. I'd go
with the 180 too.
But also since it has been setting a while it would be a good idea to
put some ATF in the cylinders and letting it soak a while. Do that a
couple of time or so to free up any stuck rings you may have.
Have you done a compression check?

never hurts to be sure.
let it sit a day or 2.
crack the oil pan drain plug open just enough to leak.
No green?.....good, then it's just condensation.
check thermostat to keep the engine operating at the right temp,
then don't worry about it.
Every engine has some blowby, old tractors you just can see it.
Good oil pressure, and no tailpipe smoke? good
I've had tired engines that would imitate a air compressor out of the vent pipe....still strong tractors.

If the blow-by bothers you, copy the newer stuff.
Plumb a fitting into the oil fill cap or vent, run a hose to the aircleaner air intake path.
too much bother? well, do what some old tractor/car manufacturers did. Vent hose on the cap, run it down underneath the tractor somewhere.
Vent is a vent. put it where you want it.

Thank you fellas for all the replies.

I have not done a compression check on it. I don't have a compression tester but I can rent one at Autozone. I'll do a compression check and then do the ATF in the cylinders and do another one.

As far as antifreeze in the oil or vice versa, I have not seen any sign of that and I have been looking, especially when I changed the oil. I will crack the oil plug and check for green when I have let the cylinders soak in the ATF for a couple of days.

It makes me feel a lot better that this is somewhat common, and not a sign of impending failure if it is just a little blowby or condensation burning off. I know the old tractor is not going to be perfect.

I'm hoping that with a new 180 thermostat and a couple of other odds and ends I should be good to go.

One thing is I think the governor needs adjustment and/or rebuild. I have the I&T FO4 shop manual for that, I'll keep you posted on how it all goes.

Here's a pic of ol' Harriet.

NoNewParts

Good idea!

On my Oliver crawler, which needed a rebuild real bad, I ran the blowby up alongside the exhaust stack. :shock:

That thing scared me cause there was no room at all for my big feet. I wouldn't have been able to abandon ship if the need arose.

" I'll do a compression check and then do the ATF in the cylinders and do another one."

Not ATF. Use oil.

Minimum acceptable pressure is 90 lbs w/ the lowest pressure reading w/in 75% of the highest reading. Run the engine to operating temp, turn it off, remove all 4 plugs, remove the breather hose & make sure the choke and throttle are both open. Crank it at least 5 compression strokes or until the gauge stops moving. Write down the first compression reading (that is the valves seating) then write down the reading after 5 strokes or when it stops increasing. You should have two numbers for each cylinder. Then, add a tablespoon of oil to each cylinder & repeat the process, but you only need the final reading for each cylinder. Write down the results & post back for help figuring out what it all means.

" I'm hoping that with a new 180 thermostat...."

Try A&I part # A-11C15 or Beck/Arnley part # 143-0024 or NAPA part number THM 184 for 180* in hose t-stats.

The car parts store folks are helpless w/o vehicle make/model/year info. Some can/will actually search on the number & cross reference, but more often than not, you will just get a dumb look. HINT: find a clerk near the age of your tractor..... Try telling them that the t-stat is for your 1977 Renault R12 1.6L L4.

All of my 180* t-stats are A&I A-11C15’s. They are a tight fit in an N hose, but they will fit. I’ve never used the Beck/Arnley or NAPA t-stats so I can’t help you w/ anything there but the part numbers.

" One thing is I think the governor needs adjustment and/or rebuild. "

Check out tip # 14 at the link.
75 Tips

Bruce,

Thanks a lot for the help. It was your tips that helped me with the governor, I plan on taking it off there and seeing how everything looks and then go from there on the adjustment. It's definitely not doing what it is supposed to.

You also saved me a search on the thermostat, I was thinking I had read somewhere on this forum about them being for a Renault. If I can get it locally I won't have to wait on shipping.

We'll see what the parts stores can come up with.

Thanks again,

Flipside

You're welcome. Glad to help.

Blow by can be diagnosed with out a guess...

I wus hope'N sumone would have ran this by a A old mechanic/machine shop operator, X sailor born again Christian Dragon slayer and said they once told me...

Blow is a interesting subject I am sure it can be diagnosed with out a guess...

I once worked on a Cadillac that blowed so hard the owner ran a garden hose from the engine all the way to the rear bumper... So far he win's

While the guessing game is going on and tricks to move the blow in another direction is anyone up to test for excessive blow to rule it out...

I will give ya a hint I use my hand...

(quoted from post at 23:09:59 12/28/14)
Blow by can be diagnosed with out a guess...

I wus hope'N sumone would have ran this by a A old mechanic/machine shop operator, X sailor born again Christian Dragon slayer and said they once told me...

Blow is a interesting subject I am sure it can be diagnosed with out a guess...

I once worked on a Cadillac that blowed so hard the owner ran a garden hose from the engine all the way to the rear bumper... So far he win's

While the guessing game is going on and tricks to move the blow in another direction is anyone up to test for excessive blow to rule it out...

I will give ya a hint I use my hand...

Click to expand...

I worked on a vacuum yesterday. That sucked!

(quoted from post at 00:09:59 12/29/14)
Blow by can be diagnosed with out a guess...

I wus hope'N sumone would have ran this by a A old mechanic/machine shop operator, X sailor born again Christian Dragon slayer and said they once told me...

Blow is a interesting subject I am sure it can be diagnosed with out a guess...

I once worked on a Cadillac that blowed so hard the owner ran a garden hose from the engine all the way to the rear bumper... So far he win's

While the guessing game is going on and tricks to move the blow in another direction is anyone up to test for excessive blow to rule it out...

I will give ya a hint I use my hand...

Click to expand...

Sure, I'm always looking to learn from you and Bob (and many others)
checking for that hidden choo-choo?
(if it was a car, I'd join Royce checking my vacuum cleaner)

This would be a start...

http://www.aa1car.com/library/engine_blowby.htm

Diesels are a different animal because of the use of high compression.... A simple hand test will not confirm blow as EZ as on a Gas burner...

http://www.dieseltruckresource.com/...ssion-92/blow-what-how-do-i-check-ect-186552/

More on the hand test later I gotta go to work

Positive Crankcase Ventilation (PCV (A little history)

http://www.aa1car.com/library/pcv.htm

If you read the links hopfully you understand were the Blow comes from and how beneficial a PCV valve is...

A N does not have a good crankcase ventilation system Thermo are no thermo its prone to issues... The original question was a possible blow-by issue.... Blow-by can tell you allot about a engine new are old on a N you do not have to disable the PCV system and plug it up to check for excessive blow-by.... Simply lay the palm of you hand over the oil fill tube after about 15 sec. if you feel pressure you have excessive blow-by, if you lift one side of your palm and it feels like you are relieving pressure you have excessive blow-by... At this point with a gas engine (gas I am not a diesel man) you have excessive cylinder pressure entering the crank case...

Suction... Well it was brought up... You will never see it on a N but it does happen on some engines... Its not a good thang possible causes are a intake gasket leak are intake valley gasket leak... You check it just like you check for blow except checking for suction...

I luv those tow straps with the loops I have 4 of'em,,, Two 12 ft'ers and Two 6 Ft'ers... Gonna order up a extra set of 6 ft'ers soon...