Engine break-in & oil pressure

Tue May 21, 2013 5:32 am

I just had my 154 engine rebuilt. Dropped the engine in and am now in the process of reconnection everything. How much oil pressure should I expect at fast idle/higher speed? Any thoughts on break-in? I was thinking of a couple of short runs (5 min.) with cool down between each, then 60 min. of light load moderate speed and gradually working up to full speed/load. Also plan to change oil and filter after the first 30-60 min.

Thanks to all in advance.

Re: Engine break-in & oil pressure

Tue May 21, 2013 6:12 am

You should expect 30 psi, or so at a fast idle. On break in, during the first few minutes, I vary the rpm not letting it run a a constant speed for more than a minute or two without changing it up or down. If everything is looking good, I run it till fully warm. About 90% of ring seating will occur during the first 10 mins. Let the engine cool and re-torque the head. Run it again, being a little more aggressive. Some time at WOT is good. Do your oil & filter change and put it to work. Modern piston rings break in very quickly and there's no need for any kind of extended break-in period.

Re: Engine break-in & oil pressure

Tue May 21, 2013 6:47 am

Getting up to full heat will take some time (5-10 minutes). Don't work the engine hard during breakin. Puts around and vary the throttle.

If you prime the oil passageways before starting (highly recommended) then pressure should establish within 10-20 seconds of run time.

Re: Engine break-in & oil pressure

Tue May 21, 2013 9:36 am

Ensure you have break-in lube or zinc additive for the flat tappet camshaft lobes.

I like to drain my break-in oil "mix" out after the cam break-in or after 2-3 hours of light use. Ensure your working oil is the right weight and add ZDDP (zinc diethyl dialkyl phosphate) as necessary to protect the cam.

Re: Engine break-in & oil pressure

Tue May 21, 2013 10:38 am

ghennessy wrote:. . . add ZDDP (zinc diethyl dialkyl phosphate) as necessary to protect the cam.

"As necessary" for a Cub engine is to add none.

Re: Engine break-in & oil pressure

Tue May 21, 2013 7:03 pm

There is a 1/8" plug on the LH side of the block at the very back, just a little higher than the oil pump. Is this the priming port? How much oil should I use to prime?

Re: Engine break-in & oil pressure

Tue May 21, 2013 7:27 pm

A/C guy wrote:There is a 1/8" plug on the LH side of the block at the very back, just a little higher than the oil pump. Is this the priming port? How much oil should I use to prime?
Yes on a priming port. Easier port in inside the oil filter housing near the top towards front of the engine. Put in 1/4 to 1/2 cup of oil. Crank engine without starting. When oil starts being pumped into the oil filter housing, pump is primed as well as the entire oil system.

Re: Engine break-in & oil pressure

Mon May 27, 2013 5:43 pm

:D

I finished putting everything back together today. Primed the oil pump from the filter housing with a few oz. of oil, then cranked the engine over with ignition disabled. I had good oil flow within a few revolutions.

Static timed the distributor, filled with water and set the idle speed up a little. It started on the first or second revolution and ran fine. Ran for about 7-8 min. until warmed up. After an overnight cool down, I plan to retorque the head, drain the water and fill with antifreeze mix, then drive around for a while at moderate speed and light load.

How long should I wait to change the oil/filter? (I was planning on change after the first hour of run time)

I noticed that the hydraulics didn't work. (sometimes does this for the first minute or two, after not being used for a week or so) I'm thinking I may need to open the pump return line where the short hose connector is located and prime the hydraulic pump with oil. Any thoughts?

Re: Engine break-in & oil pressure

Tue May 28, 2013 7:08 am

A/C guy wrote::How long should I wait to change the oil/filter? (I was planning on change after the first hour of run time)
Just my opinion. I would work the engine/tractor for a couple of hours before changing the oil. Oil filter is only partial flow, I would wait until next full service, oil change.

I noticed that the hydraulics didn't work. (sometimes does this for the first minute or two, after not being used for a week or so) I'm thinking I may need to open the pump return line where the short hose connector is located and prime the hydraulic pump with oil. Any thoughts?
Probably not the hydraulic oil pump. If you haven't done so, drain and replace the hydraulic fluid in the transmission/differential. Also replace the hydraulic filter.

Re: Engine break-in & oil pressure

Wed May 29, 2013 5:18 am

Last evening I drove the tractor for the first time (after rebuild). After I covered about 15", the hydraulics came alive and all is well. (I change the hydraulic/trans oil and filter every two years)

Thanks.