Re: oil pressure high

Thu Jan 24, 2013 8:21 am

Thankfully when it is really cold it doesn't snow, so that does make it easier. Currently it is -22C/-8F with -36C/-32.8F wind chills and it has warmed up since overnight. Been like this for 3 days with another week forecast. Thankfully when it is this cold, it doesn't snow. So no real need to go out and Imagemy tush off to plow snow, so Ellie and Granny are going to stay snug as a bug in a rug in the pole barn. In temps this cold, I do make sure that she idles for at least 5 minutes before I ask her to do anything. It takes a while for these almost 60 year old bones to get moving in the cold and Ellie is 6 years older than I am so she needs a little time too :D

Re: oil pressure high

Thu Jan 24, 2013 8:44 am

Rudi wrote:
It takes a while for these almost 60 year old bones to get moving in the cold and Ellie is 6 years older than I am so she needs a little time too

When I was younger I could handle that but now... that's too cold for me Rudi... It's warming up here,but going to snow again.Hopefully in two weeks I'm out of this place and going south to thaw out till June!!!! :{_}:

Re: oil pressure high

Thu Jan 24, 2013 10:16 am

When I first got the cub back after Dad passed, the gage was never any less than pegged. No matter how hot. One day I decided that maybe I ought to change the oil, since only God knew how long it had been. Once changed, new filter and desludged, I started to get real gage readings - pegged at startup, about 1/2 way fully hot.

The relief valve/regulator is quite far removed from the gage. It's supposed to regulate at 35 psi, iirc, which results in a cold reading of far in excess of 40 at the gage - completely normal. My one car with a digital gage shows 70 psi at startup but only 11-15 at idle fully warm - very normal.

So...I happened to look at the 1976 owners manual I have...from page 55:

Crankase, above 32F - SAE 30 (See note)
+10 to +32 - SAE 10

Note: Do not substitute SAE 10W30 or 10W40
(just saw this note)

But I'll still stick with 15W40 all year round.

Snow coming tonight - 24F outside - fire on the first piston up....

Re: oil pressure high

Thu Jan 24, 2013 9:22 pm

Not sure I can add much of value.

The operators manual shows how to flush out the filter canister (essentially put the filter bolt back in and let the kero run out the pipe on the side). I even found a cap for the drain pipe in the last Cub I bought in there :shock:

The threads on the gauge are the same as the Stewart Warner ones. I had one that didn't work and couldn't find my spare so I got one at NAPA and cut the mounting bolts off it. I think they installed a few different ones on Cubs, different 'calibration' may mean 'high' is different between different versions???

In my experience, the pressure should drop back at a low idle.

Re: oil pressure high

Fri Jan 25, 2013 7:37 am

ntrenn wrote:
Note: Do not substitute SAE 10W30 or 10W40 (just saw this note) But I'll still stick with 15W40 all year round.

I’ve been reading about the reduction of phosphates from gasoline engine oil; to my understanding because of emission issues. Zinc additive, the phosphates come from ZDDP (Zinc) in the oil is a main anti wear/antioxidant in oil that is still present in 15W40 which is recommended for Diesel and heavy duty gas engines. A lot of Diesel and heavy duty gas engines used today were built before the roller valve lifter was widely introduced in those types of engines and the zinc additive is used for a pressure additive for flat valve lifter engines.

In my opinion SAE 15W40 is an excellent engine oil but I haven’t had any problems using SAE 10W30 in any of my flat valve lifter light duty gas engines.

I always try to follow the recommendations of the manufacture and the oil engineers; they should know what’s best for their product.

Re: oil pressure high

Fri Jan 25, 2013 8:08 am

I have ran straight 30 W in my tractor and never had a problem, I let the ole girl warm up before I do anything with her.
good luck on your oil pressure problem

Re: oil pressure high

Fri Jan 25, 2013 8:23 am

Jack makes a good point - the EPA pretty much killed the zinc additives in oils due to emission warranty requirements. The diesel oils and the racing oils still carry lots of the additive in them. Some/many of the high mileage gas engine oils have put them back in - maybe because by stating high mileage, they get past the warranty concerns.

It's possible it may be more important to make sure the engine has oil in it than what type of oil is actually in it....

Re: oil pressure high

Fri Jan 25, 2013 8:53 am

Jack, the newer diesel motor oils also reduced the ZDDP content in the newer API classifications. So the 'best' reason for using 'diesel' oil is mostly lost these days. BTW there is a Shell Rotella SAE 30.

This article explains (about half way down) ... engine-oil

Re: oil pressure high

Fri Jan 25, 2013 11:45 am

Guys, in my experience oil weight has little to no effect on oil pressure.

My old LoBoy would start at around 35 and drop down to about 15 after mowing the lawn. This was on SAE30 oil.

OK, I tried SAE40. Same measurements.

OK, I went to 20W50 so the oil would be thicker when hot. Oil pressure didn't change a bit.

Re: oil pressure high

Tue Apr 30, 2013 11:31 am

I had the same problem after an oil change last month in my '47 when I changed the filter for the first time in a while (I do not change the filter every time I do the oil).

At the risk of starting a fight I will say that the oil filter serviceability on the cub is poor at best: my friend had painted my machine and I had a very hard time to make sure I did not get paint or other debris down the filter housing since it is flat flush against the block, not visible from the top of the engine with the fuel tank and sheet metal on it, and prone to dirt and debris (paint chips from the cover) getting in. I was paranoid and looked with a mirror to make sure I did not get any junk in there. To top it off the original covers bend and even after replacement with a stamped one it took a week of messing around to get a composite/steel rubber hydraulic o ring to put in top to stop it from leaking.

That said: After changing the filter and replacement with 30 weight oil, the oil pressure was pegged to the right and would not move. Worse, the engine was smoking on and off which it never did. This was going of for a week and I was worried I got crap got down the oil filter housing and I ruined it. The trouble is the smoking was not consistent, and I was baffled by the pressure. So I looked on this site and the the tech manual and saw that this is a "dry" forced lubrication system with the crank entirely above the oil in the pan. There is an oil channel and reservoir inside the block ending in the oil pressure regulator for return to the crank case. I believe this design suites it well for non detergent oil and settling of debris in the pan and dirt from fields and such? Now, I am running non detergent oil because I am stuck with it from the beginning. So on a hunch I drained the oil filter plug stem which I forgot to do. A sausage of sludge came out and then 3/4 of a quart of oil. However the machine had been sitting got a day...and the oil pan dipstick still read full. There was 3/4 of a quart of oil trapped in the reservoir somehow. My guess was that sludge freed itself from the filter housing and clogged the regulator shut. All the oil being forced into the engine lubrication reservoir was exiting under the highest pressure possible through the push rods and crank journals, forcing oil to get into the combustion chambers. At risk???, I wound the engine up to 1800 rpm and let it run for 15 minutes. She was still smoking. Then I quickly dropped it down to an idle. The oil pressure was still pegged. I repeated this process four (4) times over an houruntil finally the oil pressure dropped and now tracks the engine rpm. No more smoke! No more excess pressure.

Re: oil pressure high

Tue Apr 30, 2013 9:26 pm

Not sure it would have helped, but the Op manual says to drain the 'oil filter drain pipe' before pulling the filter. It seems this is pretty well ignored, judging by the Cubs I have seen. It also says to inspect the small metering hole at the end of the oil filter retaining bolt, if plugged with will stop all flow through the filter. A Cub does not filter all the oil. Since the oil pressure gauge is in the filter housing I wonder if that being plugged would build up pressure??

It is also a good idea to flush the filter housing, put the bolt back in and use kero, draining it though the pipe. Good idea on any 'new' Cub. I even found the drain pipe cap in my last Cub! Another I found the copper washer for the bolt.

Glad you fixed your problem. Thanks for filling us in.

Edited to add the picture: flushing the filter housing, found a 'stray' pipe cap in there! Note the cap 'bolt' keeps the junk out of the oil pan and down the pipe....

Re: oil pressure high

Wed May 01, 2013 10:40 am

Thanks for the additional input.
Yes I believe what you could drop just about anything down inside there due to its location and lack of easy inspection (unlike the older "A" bell housing design which was superb)
I wonder how many cub engines unknowingly have met their eventual demise because of this design.

You are right, from my understanding the partial oil filter system is alongside and in parallel with the oil channel in the block. I believe the overall pressure is still determined by the oil pressure regulator, though: The gauge does not explicitly show the pressure against/through the filter but the overall lubrication system pressure. The filter could be completely clogged and not allow any oil through and I do not think this would effect the pressure gauge which is essentially a "tap" into the system? Unless there is a flow splitter somewhere else, I do not see how this could be otherwise.

Anyone else have any info or comments on this?