Rebuilt engine - break in oil??

[ThePunisher]

I have a '52 Ford 8N and I just had the motor completely rebuilt. I live in the snowy north, and the temp here is starting to get pretty cold. My engine builder said the best oil to use for the break in is Rotella 15w40, but he expressed a few concerns over the low temp and the thickness of this oil. He originally said a good quality 10w30 would be OK, but would prefer the Rotella 15w40. The temps here are currently right at the freezing point, but I anticiapte it getting much colder soon...should I go with 10w30 because of this? The tractor is indoors in an insulated garage, but it is unheated. What do you folks suggest? I have not yet started the new motor...

 

[HCooke]

I think 10w30 would be good for the next few months
and then switch to 15w40 next summer.

 

[8N1949]

If it was mine, I would use the 15 W 40 oil for a three hour break in period and change to straight 30 weight. Before you do anything, read this.


FORD 8N REBUILT ENGINE BREAK-IN PROCEDURE

You have just installed a newly rebuilt engine and discover there is next to nothing published concerning break-in procedure. Here are my thoughts on the subject. This same procedure with minor vehicle-specific variations has worked for every engine I have rebuilt.


The second worst thing you can do to any new or rebuilt engine is let it idle or run at a steady RPM. Revving the engine splashes plenty of oil up into the cylinders. You also have to get some cylinder pressure behind the new rings to drive them into the walls. Revving the engine with a load on it takes care of that.


Most of the problems with rings not sealing and or cylinder scoring are caused by being too gentle or taking too long to tune the carb. There is no need to even tune the idle circuit until after you have taken the engine through a heat cycle. At that point your rings should have already "set". Slightly rich is better than too lean, so I always set my carb up slightly rich on the bench. For the Ford N-series Tractors, the idle mixture screw should be set 1 turn out and the main mixture screw about 1-1/4 turns out.


Now, this is how I avoid extended idling while tuning the carb on my tractor. If you prevent the engine from idling below 800 RPM it will be running off the main mixture and the idle mixture adjustment will not matter. To do that, I simply crank about two extra turns in on the idle speed screw past the normal bench setting of one turn in from throttle plate fully closed (3 turns total). For the next step, rigging a temporary foot-throttle may help or you can just use the standard hand throttle.


Crank the engine up and keep revving the throttle up and down until the temperature starts to come up. Then, the best thing you can do is put it in gear and drive it around. Continue to accelerate and decelerate the engine repeatedly with a load on it letting the RPMs get higher and higher as the temperature comes up. Run it like that for about 5 or 10 minutes watching for any serious leaks or other problems and then shut if off and let it cool.


Once it has cooled, go back and re-torque the head bolts and carefully inspect for leaks and the inevitable things like loose hardware, or dangling wiring. Then crank it up again and run it through another heat cycle with a varying load and RPM on the engine.


YOUR INITIAL BREAK-IN IS NOW COMPLETE

 

[TheOldHokie]

(quoted from post at 20:40:37 12/12/11) I have a '52 Ford 8N and I just had the motor completely rebuilt. I live in the snowy north, and the temp here is starting to get pretty cold. My engine builder said the best oil to use for the break in is Rotella 15w40, but he expressed a few concerns over the low temp and the thickness of this oil. He originally said a good quality 10w30 would be OK, but would prefer the Rotella 15w40. The temps here are currently right at the freezing point, but I anticiapte it getting much colder soon...should I go with 10w30 because of this? The tractor is indoors in an insulated garage, but it is unheated. What do you folks suggest? I have not yet started the new motor...

This is a low RPM 20 HP flathead not a high performance race engine. No need for anything fancy - same oil you are going to run in it. The Rotella diesel line has a little higher zinc content which is good for break-in. Since you are in a cold climate I second your rebuilder's advice - go with the Rotella 10W30 - it will provide better cold weather protection to your new baby. Personally I would stay with 10W30 after break-in if your hot oil pressure is 30 PSI or better which it should be. That's what I run in mine year round here in balmy MD (overnight lows in the teens during the winter months).

TOH

 

[ThePunisher]

Thanks for all the great info everyone...

 

[teddy52food]

I would run a straight # 10 detergent in it myself over winter.

 

[farmsjake]

In the winter here in north central Wisconsin I
use 10w30 synthetic and in summer I run
15w40 synthetic. I only got about 25 hours on
my complete rebuild.

 

[36 Coupe]

The cold pour point of Shell Rotella 15/40 oil is much thicker than 30 wt oil.Charts have been on the forum that show this.I have a hi milage F150 pickup.I put some 15/40 in it in December during an oil and filter change.The oil pressure gauge was all over the place when I started the engine.I think the worn oil pump had trouble pulling that cold oil thru the screen.We all have had engines that were slow in building oil pressure after an oil change.The pumps drain down and lose prime.The 8N engine has to pull all its oil thru a small screen on start up.My truck showed erratic oil pressure on starting until warmer weather.I just did an oil and filter chance on the truck.Used Chevron 10/30.Little delay on oil pressure on starting.Pressure was steady.I suggest you put a sample of 10/30 and 15/40 in the freezer for a while and compare the thickness of the 2 samples.I wont use 15/40 in my truck after seeing the difference in cold startup pressures in my truck.I agree with your mechanic on the 10/30 oil.Add a sample of 30 wt oil to the freezer test.Do not take every thing you see on here as gospel.Many posters are dead wrong because they are posting things they have heard but never proven.

 

[36 Coupe]

I disagree with you 1000%.There are plenty of engines running over 200000 miles with out complicated breakin procedures.I think that Multi weight oils and higher engine temperatures have made longer engine life possible.

 

[souNdguy]

new rebuilt?

break in?

very cold?

here's twhat I would do.

go buy some cheap walmart 10w30, and 3 oil filters. fram C3 cheapies are ok for 2 of them, and a decent napa 1010gold fo rthe last one.

put the oil in and 1 new filter.. cheap one.

run it 20 minutes, change that filter out.. it should have immediately grabbed any big flecks and chunks that circulated and actually made it thru to the filter. you are now on your 2nd cheap filter. retorque the head bolts now....

now go break the machine in.. do some work with it.. mow for a few hours, plow something.. get some hours on the machine. good 5 hours different spepds and rpms..

now.. get some synthetic oil and change it to that and the new filter.

I'm currently using walmart synthetic oil in a 63 4000 that I just did some top end work on.

in your area, a 5w30 syn sounds great...

should be easy on starting cold, and provide you with much more cold start protection.

plus the walmart syn oil for 5qts is only like 25$ or less

soundguy

 

[TheOldHokie]

(quoted from post at 08:53:46 12/13/11) The cold pour point of Shell Rotella 15/40 oil is much thicker than 30 wt oil.Charts have been on the forum that show this.I have a hi milage F150 pickup.I put some 15/40 in it in December during an oil and filter change.The oil pressure gauge was all over the place when I started the engine.I think the worn oil pump had trouble pulling that cold oil thru the screen.We all have had engines that were slow in building oil pressure after an oil change.The pumps drain down and lose prime.The 8N engine has to pull all its oil thru a small screen on start up.My truck showed erratic oil pressure on starting until warmer weather.I just did an oil and filter chance on the truck.Used Chevron 10/30.Little delay on oil pressure on starting.Pressure was steady.I suggest you put a sample of 10/30 and 15/40 in the freezer for a while and compare the thickness of the 2 samples.I wont use 15/40 in my truck after seeing the difference in cold startup pressures in my truck.I agree with your mechanic on the 10/30 oil.Add a sample of 30 wt oil to the freezer test.Do not take every thing you see on here as gospel.Many posters are dead wrong because they are posting things they have heard but never proven.

While I agree with you on the relative viscosities of the different grades :shock: your focus on pour points is misdirected and factually wrong . Where did you get your pour point data?

From the manufacturers product data sheets:

[i:d075b84117]Valvoline Premium SAE 30: pour point -27C
Shell Roteall T SAE 10W30: pour point: -30C
Shell Rotella T SAE 15W40: pour point: -30C[/i:d075b84117]

Not diddly difference in the pour points of those three oils. But there is a very substantial difference in the operational viscosities of the oils at various temperatures and it's measured by something called their viscosity index (VI). Plugging the 40C and 100C viscosities from the product data sheets into the Widman Oil operational viscosity calculator to get operational viscosities at a balmy 0C (32F):

[i:d075b84117]Valvoline Premium SAE 30 (VI 114) - Viscosity 1088 cSt @ 0C
Shell Rotella T SAE 15W40 (VI 135) - Viscosity 1508 cSt @ 0C
Shell Rotella T SAE 10W30 (VI 142) - Viscosity 904 cST @ 0C[/i:d075b84117]

THE FACTS:

1) The viscosity of SAE 10W30 is [b:d075b84117]25% less [/b:d075b84117]than Valvoline SAE 30 at freezing tempertures (0C/32F).
2) The viscosity of the Rotella SAE 15W40 is[b:d075b84117] 20% greater [/b:d075b84117]than SAE 30 at freezing temperatures (0C/32F).

THE WHY:

Number 1 is a reflective of the much higher viscosity index of the SAE 10W30 - it thickens at a much slower rate than the SAE 30 as it is cooled.
Number 2 is reflective of the fact that despite SAE 15W40 also having a higher viscosity index it starts out a lot thicker @100C and never catches up to the thinner SAE 30 as the temps drop and they both thicken.

And keep in mind these numbers are product specific. Different brands will have slightly different viscosities but the basic bahavior will still be the same.

TOH

 

[Dean]

I prefer a low viscosity oil upon initial start up. You want the rotating assembly to throw lots of oil onto the camshaft/lifters and the cylinder walls (not as important on low speed industrial engines with low valve spring pressures like your N).

I usually change the oil and filter after about thirty minutes of operation (longer in a bypass system like your N) as the moly assembly lube commonly used by engine builders will be trapped in the oil filter.

Change to an oil appropriate for your climate at that time.

Dean

 

[36 Coupe]

My statement is based on what I saw on the oil pressure gauge on cold startup after an oil change.Ill keep the 15/40 out of the crank case now.A freezer test of 3 oil samples will prove my idea.

 

[TheOldHokie]

(quoted from post at 06:03:52 12/14/11) My statement is based on what I saw on the oil pressure gauge on cold startup after an oil change.Ill keep the 15/40 out of the crank case now.A freezer test of 3 oil samples will prove my idea.

Places like SWRI are in the business of rigorously conducting ASTM D-97 pour point "freezer tests" and I gave you the published results. No need to try and duplicate that at home - their tests are very well controlled and quite accurate. All three of the different grade oils I listed have the same pour point.

Your basic idea vis-a-vis SAE 15W40 and SAE 30 has already been proven and I gave you the data to support it. But your analysis is focusing on the wrong property. Kinematic viscosities at 40C and 100C (e.g. viscosity index) is what you should be comparing - not pour points. Just FYI the Rotella SAE 10W40 and Valvoline SAE 30 viscosity curves cross at about -10C (14F). So at temps below 14F the SAE 15W40 is actually thinner than the SAE 30 while above 14F the oppositie is the case. Get it???

If you really want a grade 40 oil for winter use in your truck use something like Mobil 1 SAE 0W40. It has a viscosity index of 184 and will work just fine on the coldest winter day.

TOH

[size=18:488b39655e][b:488b39655e]PICTURE OF A TYPICAL "FREEZER TEST" AT SWRI[/b:488b39655e][/size:488b39655e]

 

[farmsjake]

The Wal-Mart oil is the worst junk you can buy.