New Engine Break-in Proceedures?

30Tudor

Senior Member
I just finished putting my rebuilt engine in the car. I am just gearing up to start it up. Any recommendations on break-in proceedures?
 
I'll second the recommendation to follow the proceedure put forth by Antique Engine Rebuilding. I have followed his tips on three engines and they have broken in as anticipated. Gar Williams
 
Thanks for the reference.

What I am hearing from a couple of people is the following:

For the modern head gasket. First run it for 20 minutes, let it cool down to stone cold and then retorque the head gaskets.

Second time you start it, get it on the road and run it hard for the first 100 miles (i.e. acceleration and up hills) to get the rings seated in properly.

What have other people done?

Mike
 
Those were the instructions that came with the modern head gasket for the Synder's high compression head.

Mike
 
It has been my experience that more than one retorque of the head gasket is required. With the higher compression head, new grade eight studs and nuts, and either the new "silicon" or the original style copper clad gasket, the gaskets have compressed enough to require a number of torque checks in the first thousand miles. Several members in our local clubs have neglected to pay attention to the torque after the first several hundred miles and have had failures. It is a very simple quick job and well worth the effort. Gar Williams
 
Here is some info from a fellow club member...

Excerpt from Ron Bishop, "Rebuilding the Ford Flathead," which has appeared in installments in Skinned Knuckles

There's one thing certain about breaking in a rebuilt motor; if you ask a dozen different people what's the proper way to do it, you'll get a dozen different answers. Everyone seems to have a secret formula for breaking in a motor, and he's con­vinced that his is the only right way to do it. There seems to be one common element in all of them; everyone will agree that the most important factor in breaking in any engine is the seating of the pis­ton rings.

Getting a good sealing surface between the rings and the cylinder wall is what determines whether or not the engine will burn oil and also whether or not is will make horsepower. The best way to establish a good ring seal is by running the engine at varying rpm for the first few hundred miles. Be sure to spend some time in deceleration as well as acceleration during the break in. The ring seal is governed by the gas pressure exerted on the rings, and that pressure is determined by engine speed. Running at a constant speed will generate a balanced pressure and may lead to polishing of the cylinder walls. Therefore, continually varying the speed during break in is of importance. The accel­eration/deceleration cycle is necessary because this will load both sides of the rings against the walls.

As soon as the motor is started it should be set at high idle which will allow oil to circulate through the engine. Oil pressure is important, so keep an eye on the oil pressure gauge. Also keep a close watch on the engine temperature gauge to avoid any chance of overheating which could dis­tort the internal components at this critical time in the engine's new life. After the engine has reached operating temperature and runs for 20 or 30 min­utes, recheck the ignition timing and adjust the carburetor for correct idle speed. Shut off the engine and retorque the head and manifold bolts. Check oil and coolant levels.

Don't take any long trips and don't run the engine at extreme rpm. After the first couple of hundred miles, change the oil and oil filter. It's also a good idea to spend some time checking the engine compartment for loose belts, hoses, elec­trical connections, and so on. Once the 200 mile mark is reached, you may go ahead and run the engine the way you plan to drive it. If it's not broke in by the time you reach the 500 mile mark, it probably never will be.
 
I like what '30 Tudor' has posted. Seems to make a lot of sense to me. I didn't have benefit of Ron Bishop's comments prior to first operating my engine. i do have the 'NEW CAR DIRECTIONS' that Ford placed in every car that left the factory and have been following it. The engine seems strong, pulls good going uphill, and responds well to the throttle. Have not exceeded 35 mph in 210 miles.

Best Regards
 
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