1948 8N Oil Pressure and Governor Help

[Hiney]

I am looking for some help with my 1948 8N. I have finally got it to run. When it first starts it has 40 psi oil pressure at idle and then after it warms up only has 5 psi oil pressure at idle. As you move from idle then the oil pressure will move to around 20 psi but no higher. I know that once the engine warms up the oil is warmer so the pressure may be less, but I think that this is excessive. Any thoughts?

The second question is about the governor. Is there any way to check the governor to make sure that it is working correctly? When I move the throttle up just a little from idle, the engine seems to go to rev up to full RPM. The throttle on the quadrant is not even close to the top of its travel. Any thoughts?

Thanks,
Hiney
 

[arthur ward]

i advise s.a.e. 30 wt. oil in the summer. once the engine is warmed and working hard it will drop. 10 - 15 psi when worked hot and let down to idle doesn't suprise me.

i use castrol sae 30 in the summer. if you look at 30 wt oil when you put it on your finger during the hot summer...it sures looks thin to me. just think what your poor car engine goes thru with 10w30 in the summer or even 5w30.

even though current oil far exceeds oil from 50 years ago..there is still a difference. many in fact. sheer is a major problem with oil. when oil heats and sheers...then you have wear. better hope you have zinc in your oil at that time(castrol does).

my ratings are kendall race oil then castrol oil as best from all the info i studied. sythetic may leak around vintage gaskets. front rope seals on N engines would probably leak sythetic but i haven't tried it.

the worst thing for an engine is to start it over and over and over. once running...use it.
 

[Colin King]

Sounds like nothing is wrong with your oil pressure. Even 5psi at hot idle is considered okay for these older engines. Your 20psi revved hot is great!

Colin, MN
 

[8N'r--WI]

Hiney--first off, I would move your throttle arm to the low end of the quadrant so the engine is idling. Grab the short, non-adjustable rod that hooks to your carb and governor and "jazz" the rod.

If the governor is working at all you should feel a "noticeable" tug on that rod. If you do not feel any tug, remove both the short and the long rod from the governor, as well as the oil line that lubes the governor.

Remove the 2 bolts and the governor will pop right off. Check the 4 steel balls in the governor for flat spots, as well as the upper and lower race for wear. If they need to be replaced, it is an inexpensive fix. (your gov. probably is leaking oil anyway and you can address that at the same time).

If the governor pans out OK, I would then adjust the long throttle rod that connects from the governor to your throttle assembly. On both the 8N's that I have worked on, the adjustment was the problem with getting the engine to idle right, and maintain constant RPM's when using the tractor.

Common mis--diagnosis points to your carb---usually not the problem fixer----post back with results of what you find.

Tim
 

[TheOldHokie]

Consider some hard data from a couple conventional motor oil product data sheets chosen pretty much at random:

Castrol HD SAE 30

Kinematic Viscosity @100C 11.5 cSt
High Shear Viscosity @150C 2.9 cP

Pennzoil HD SAE 10W30

Kinematic Viscosity @100C 11.7 cSt
High Shear Viscosity @150C 3.5 cP

Makes one wonder doesn't it?

TOH
 

[souNdguy]

Ditto on the info about the gov and the oil. 5psi hot idle. while not bragin' rights.. is still acceptable. i fthis is on 30w oil.. move to 40w oil on next change and you might see 7-8 psi hot idle.. wich is almost respectable on these old machines.

Do check the gov. one thing though.. goose the throttle fast.. if it stumbles any.. check your carb main jet to make sure it is not way lean. or way rich ( sooty smoke )

Soundguy
 

[arthur ward]

where did you get that info from? if from a website...can you give me the link?

thanks
 

[TheOldHokie]

Those numbers are from the product data sheets on the Pennzoil and Castrol websites. Product Data Sheets for most all major brands of engine oil are available on the manufacturer's websites and contain detailed test results for their individual motor oil products. In particular they usually contain the results of the viscosity tests that are required by the SAE viscosity grading specification (J300).

You might also find this an interesting read:

http://mysite.verizon.net/oldhokie/windyridge/oil.pdf

It's a compilation of historical and technical info about the specification which I've culled from a number of different sources. It's a tad long and a bit geeky but I think the historical content is particularly relevant to the interests and concerns of many members of this forum. I'll be adding a section describing the actual viscosity testing procedures currently mandated by J300 in the near future as I think it clarifies exactly what performance characteristics the individual specifications are designed to measure.

Hopefully you'll find it as interesting as I did when doing the research. And by all means - if you find any factual errors in the content please let me know.

TOH
 

[arthur ward]

Regarding Penzoil 10w30:

high shear viscosity is cP 3.1 not cP 3.5

Viscosity at 100`C is 10.4 ...i don't know where you got 150`C from

one thing they don't list is zinc and ash content.
 

[TheOldHokie]

Off the top of my head I'm guessing you looked up a different product. Pennzoil Heavy Duty SAE 10W30 Motor Oil is what I looked up.

• The high shear viscosity test is measured at 150C (and 3600 RPM) per the SAE requirements.
• Kinematic viscosity test is measured at 100C (and much lower RPM) also per the SAE spec.

Look at the 1999 SAE J300 table of requirements in the link I gave you.

IIRC the Pennzoil HD product sheet lists zinc at .11 as opposed to the Castrol at .09. I don't recall if the ash was listed or not - it usually is along with a lot of other useful info.

But you seem to have missed my basic point which is that the SAE grade designation only tells a piece of the story. And that a multi-grade will have, for all intents and purposes, the same viscosity at normal engine temps as the corresponding single grade. The grade specifies a range (two ranges actually) - not an exact number. Without looking each specific product up you can't even reliably predict which will be higher, the monograde or the multigrade, the traditional or the synthetic, etc.

TOH
 

[TheOldHokie]

[arthur ward]

ok...i got ya. another guy told my about the pennsylvania crude...instead of saying pennzoil.

they actually insisted that the oils drilled from pennsylvani have a high ash content simply because of the soil that it comes from vs. the texas oil fields.

same guy also told me that sythetic oil leaked out his gaskets on his rebuilt chev 350 motor. he put that in after breakin with regular oil.

i would use sythetic in my 8n's just rebuilt motor but i don't know if those rebuild kits have proper gaskets for it or not. the front seal is a rope seal i guess.

i think that one could get away with the cost of sythetic oil year round in wisconsin. just change it every spring. as long as the tractor is worked enough to evaporate the condensing water in the winter time. i just spent $1750 on the motor rebuild and want only the best for that precious engine.

here is a link to a site that kinda explains some stuff. i base my decision on a few things like the zinc, ash, viscosity...etc.

let me know what you think of it, ok?

here is the link:
http://www.unofficialbmw.com/all/misc/all_oilfaq.html
 

[TheOldHokie]

I visited that link whilst compiling my "research paper". It has a very comprehensive discussion of the chemical content - ash zinc, etc and a very detailed chemical analysis of a lot of competing oils. I am not very knowledgable in those matters and I take it with the normal large grain of salt I reserve for most self appointed web experts (like me!). It's probably reasonably accurate and well intentioned.

However it has several factual errors in the very brief discussion of the SAE viscosity grading scheme. That leads me to believe the writer is repeating information he picked up anecdotally rather than through any hard research. I doubt he/she has any in depth understanding of the current system or how and why it evolved.

If you read my "treatise" you'll find mention of the differences between Gulf crude and PA crude. Those differences were recognized by the automotive engineering community as early as the 50's. My discussion of the differences centered around the fact that PA crude yielded oils with higher viscosity indexes - meaning a Pennzoil SAE 30 didn't thicken up as much as an SAE 30 oil refined from a Gulf crude when it got cold. That was a major performance advantage in cold winter climates. It motivated a chnage in the SAE grading specifications and it was very much a part of the drive to develop multigrades.

I don't care what oil anyone uses in their motors except me. It's your tractor/truck/hotrod etc. Do what you want. But I think if you want to make the best decision possible you need to get as much factual engineering info as possible to aid you in making that decision. And there's a lot of FUD floating around on the Internet and in the various gearhead forums. We all need to be very careful what "facts" we parade around. I for one have been enmbarrassed to find that some of my facts weren't. I hate it when that happens.

I think we are in pretty much in agreement on the basic issues. Nice chatting with you - now let's leave these folks to a little peace and quiet ;-)

TOH
 

[Joe(NYC)]

One caution when putting back the 2 bolts on the governor. I have read here many times that the bolts are two different lengths. If you put them back in the wrong holes you will do internal damage. Make sure you mark them correctly as you take them off.
 

[arthur ward]

Hokie, This is the mobile 1 10w30 specs off their site. WOW, i didn't think that penn 10w30 would be better than the mobile 1 also.

Mobil 1 10W-30

Viscosity, ASTM D 445
cSt @ 40º C 62
cSt @ 100º C 10.0
Viscosity Index, ASTM D 2270 147
Sulfated Ash, wt%, ASTM D 874 1.0
HTHS Viscosity, mPa·s @ 150ºC ASTM D 4683 3.14
Pour Point, ºC, ASTM D 97 -45
Flash Point, ºC, ASTM D 92 224
Density @15º C kg/l, ASTM D 4052 0.86