engine break in procedure

[wisnia07]

Hello everyone!

With your great help, I'm finally done with my 280 engine rebuild. The engine is in the car and it's ready for the first start-up.

I am wondering what is the best engine break-in procedure for our engines. I've spent some hours googling the subject and found out two different approaches: easy and a hard one. How do you break in our engines?

The engine is filled with Millers Trident 10W40 semi-synthetic oil and I'm not sure if it's good for the break in period. Shall I use some ZDDP additive (for example ZDDP Red line break-in)? How many times and exactly when should I change the oil and filter?

I'm sure that breaking in the engine is very important and I don't want to mess anything up.

Thanks for your help,
Wojtek

 



 

[ja17]

Consider using a good break-in-oil. I never had good luck trying to use synthetics for break-in. Synthetics seem to be  too slippery for the rings to seat. Make sure you have the upper oil filter housing seal in place or your engine oil will not be filtered. Short start-up and running a little longer each time seem to be a good way to begin, tweaking  and adjusting as needed. Allow to cool between runs. I do a head bolt re-torque and valve adjustment after first warm-up.  Adjust valves after engine cools.  Always loosen radiator cap before re-torqueing head bolts. Watch your gauges!!

[Tyler S]

Before the first startup, remove the fuel pump fuse and crank the engine until you have oil pressure on the gauge.
Alternatively, a better safer procedure is to remove the tachometer cable and drive sleeve, then remove the vertical tach/oil pump intermediate shaft. Insert a long rod with a notch at the end to couple to the oil pump shaft. Chuck it into a drill and prime the oil pump. Be sure to set your drill clutch loose otherwise you may get hurt when the pump primes and the drill kicks out of your hand.

[Benz Dr.]

I spin the engine over without spark plugs until I see oil pressure. Since there is no load on the crank or bearings there's very little danger of damage. After the engine starts I let it run at a fast idle until it warms up and then re-torque the head bolts.

There's a lot more to breaking an engine besides just starting it. I start with driving at slow speeds and light throttle and gradually increase road speed and throttle opening while the length of time I accelerate is increased in direct proportion. The idea is to use different engine speeds and load to make the piston rings bite into the cylinder walls a little bit. Load will cause the rings to remove high spots on the cylinder walls while while light or no throttle will allow a bit of a polishing effect. Proper break in can take several hundred miles and I figure that when the cooling fan rocks backwards at shut down then your engine is fully broken in. If your engine stops dead then it's still tight.

Driving around the town for the first 200 KM isn't a bad idea. The one thing you shouldn't do is go out and drive at the same speed all day long before your engine is properly broken in. I've seen the exact or very similar break in methods detailed in MB literature so I feel confident in passing this method along.   

[George Des]

When I did my engine, I had a pressurized oiler. Essentially a tank you fill with oil and then pressurize. This is connected to the engine-can’t recall exacly where and then the valve is opened up to fill all the oil gallies in the engine. Many ways to do it including the drill in the oil pump drive. Other thing I was told to do was to pack some prelube in around the oil pump vanes to help with the initial prime. Maybe overkill but I did anyway.

[wisnia07]

Thanks for all your answers!

I will go for a special break-in oil, as Joe suggested. How many times during the break-in period would you change the oil and filter?
I heard of someone changing it every 200km, but that was on a modern turbocharged engine. That seems crazy too often to me.

I had primed the engine just after I got the cylinder head mounted. I placed the timing chain away on the manifold side, and spinned the IP sprocket by hand. I used a garden hose as a by-pass in place of the cooler.

Thanks for the procedure, Benz Dr.! I will follow your suggestions.
I've searched the forum before about the break-in steps, but only just now I discovered this post https://www.sl113.org/forums/index.php?topic=27005.msg193669#msg193669

With all this information I should be fine. Thanks again for your great help!

[Rolf-Dieter ✝︎]

Hello Wojtek (wisnia07)

Glad you found the link for Robert. He was my business partner for 25 years in the Turbogenerator business. His hobby is old-timer American cars and he rebuild car engines (Chevelle, Corvette, Cadillacs etc.). He does not own a Pagoda as of yet, however, each time he visits me here in Ontario his interest level goes up, perhaps some day he will have to look after my car one way or the other, time will tell. ~smile~

We are both retired now after looking after our Customers Steam Turbine Generators (ranging from 5 MW to 300 MW) in the Pacific North West of Nordamerica as well as the US, Australia and the Philippines.

He is not only a brilliant Turbine Engineer his passion is old-timer cars he has quite a few of them. I may just drive my Pagoda across the country and together with his help do some major work on it. I initially invited Robert here and to comment on Tom's question. And that he did in great detail.

It goes without saying that the 25 years I spend with Robert as a business partner were the most satisfying years of my working life.

Best,

Dieter