The Stovebolt Site Forums The Shop Area Engine Shop 235 Engine Brake-In

Now that I’m ready to start my ’53 power glide engine after a complete rebuild, I’m wondering about the initial break-in. I have already primed the system by spinning the new oil pump and it makes 40 PSI and oil comes all the way through the rocker system. The machine shop that did the boring and crank grinding said “when it starts as soon as you see oil pressure take the engine to 2000 RPM for 20 minutes to properly ware-in the new lifters and cam”. Then drive 100 miles at varying speeds and change the oil at 100 miles. They recommended a good 30 weight oil and a pint of STP. Any other ideas or comments?

20 weight

The initial 2000rpm run is to work harden your cam and lifters.
You would be amazed how easy it is to wipe out a new cam/followers if you don't.......(Don't ask!)

The advice you've received is good but try not to lug the engine during the break in period.
It's not good practice anyway, regardless of the age/condition of the engine.
All that achieves is excessive engine wear and wastes gas.

The oil change is critical too as this first fill will effectively flush the engine and trap any 'nastys' including the initial break in wear.
I would change the filter too.
The extra $$$ spent now will pay dividends later.

Good luck and enjoy!

RUN, do not walk away from anyone who reccomends STP for break-in. Back when I used STP for engine assembly, I had repeated oil-related failures for no good reason, mostly premature rod or main bearing wear. I even built one more engine that way, just to convince myself it was a fluke- - - - -nope, same results, a scored main bearing! Otherwise, you've gotten some good advice. The high-idle break-in is necessary to assure plenty of splash lubrication to the cam and lifters while they're establishing a running fit with each other. Make sure you've got plenty of cooling, maybe a fan or squirrel-cage blower aimed at the radiator during the initial run-in is helpful.
Jerry

Thanks, guys, for all the advice.

It started on the second revolution with the starter, ran for 15 seconds then stalled. On the second try it started on the second or third revolution and continued to run, the oil pressure came right up so I took it to 2000 RPM and held it there for 10 minutes.

I had initially set the timing at the ball using a continuity light across the points, but when it started the engine seemed to be trying to “catch up to the starter” so I advanced it several degrees on the octane selector and after checking for leaks and other stuff gone wrong I restarted and ran at 2000 RPM for the second 10 minutes.

The radiator has a new core (much more efficient) with the old tanks so it did not over heat. After it got to temperature I could see the gauge respond as the 180 thermostat opened and closed.

Jerry:

Your advice on STP is too late. I sure hope I don’t suffer the same fate. I did spin the oil pump for several minutes on two different occasions and had turned the engine at least 4 revolutions by hand while adjusting the hydraulic lifters between the times I spun the oil pump. What would you recommend as a zinc additive to the oil?

I really can't say why my STP experience was so bad, but after losing a pile of money on several rebuilds, I just got really gun shy about using it. I've been using 15W40 DELO oil for quite some time on engines with high mileage, or ones I think can use the extra zinc compounds. I'm not sure if they still add extra zinc to diesel rated oils, but they do perform well with the extreme pressure present in engines with 22:1 compression, which would be way above the cam lobe loading on a stovebolt. BTW, the letters DELO stand for Diesel Engine Lubricating Oil, something I learned back in the 1950's when it was reccomended for customers of Dad's shop whose engines were experiencing hydraulic lifter problems. Hydraulics gave a lot of problems, particularly the ones Olds and Cadillac used in their first-generation overhead valve V-8's.
Jerry