Breaking in an engine on a stand vs in-car

S

sonny30coupe

Senior Member
I have a newly rebuilt engine ready for the car. I also happen to have an engine test stand that is set up with radiator and the works. My question is, is it really a good idea to run that engine on the stand before it is put in the car after the resto, or should the engine have the forces at work against it that it gets when being ran in the car. Shouldnt it be ran with the pull on the motor and all or is good to let it just "freewheel" on the stand with no drag on the motor? I hear of guys on here all the time running engines on test stands but not sure if it is a wise idea to do so. I would like to hear it run before it gets installed in the freshly painted newly restored car just in case there is a problem and it would need to be removed. Your thoughts please. Thanks in advance, Sonny
 
I think the answer is "with moderation." It is not good to run a new motor for prolonged periods of time without a load, as the rings will not have the proper forces to break in. That issue aside, there is a happy medium whereby the engine can be run at high RPM on the test stand for a short period (10 minutes ) or so to break in the cam, and check for leaks. MHO
 
I like to run the engine before installation if possible. I fire it up and rev it slightly and back to idle a few times, until it gets to operating temperature. I then shut if off and let it cool to room temp, check the head nuts and start it up again and run it up to operating temp again. I like to do this two or three times, then install it and drive it lightly for at least a few miles before turning it over to the owner.

At my last job I had to overhaul a big diesel engine for the front end loader. I fired it up just setting on it's oil pan on the floor. Everything sounded good, so I then went ahead and installed it into the loader.

It's 12:30, just after midnight, and I'm at Mark's house in a north Chicago suburb and just heard some coyotes outside his house. I didn't know they were this far east, and this close into the city.
 
if you can install the trans on it also that is what i would do. there was a time where we did a car and everything was rebuilt and new and the stupid through out bearing was bad.(it was a new piece) so we had to take the rear and trans out and change it and then reassemble.(on our dime no less) i say run it on the stand.
tk
 
Sonny,
I run engines on a stand for about four hours varying the speed, shutting it down to cool and retorque the head as required. I like to verify there are no leaks and I also do a compression test twice during the run-in. I like to know the engine is right and have data to backup my work prior to delivering the engine. More than once during the first couple engines I rebuilt, I had to chase a rear main leak and it was much easier to remove it from the engine stand than a car. The other reason I like to complete this run-in period...I have control of the initial ring seating. I find from the compression tests I do the rings are well on their way to seating after this 4 hour process. Just my preference...
Another thought...If you plan to use a "block sealer" in the coolant, it would be wise to do so on the stand rather than your car.
Moderation was mentioned in an earlier post...use moderation describes the process of breaking in an engine whether on a stand or in the car.
Good Day!
Dave in MN
www.durableperformance.net
 
The high dollar engines we run in aircraft are usually run in on a test stand with either a test club (propeller) or in the case of turbine engines, on a run stand with a water brake so it can pull power. This is the only way a rebuilder/overhauler can sign an engine off as completely overhauled without installing it in an aircraft. If it is entended to be "run in" in the aircraft, it can only be signed off with a partial maintenance release till the test run is completed.

One of my bigest customers is the USDA APHIS Wildlife Services branch. Their job is to thin the coyote population and try to keep it healthy. They drop rabies vaccine baits to control rabies coming in from Mexico. The pesky critters are everywhere now. The latest infestation on their list is feral hogs. The damn things are not so slowly taking over down here.

Kerby
 
If I remember correctly Henry said; Place the block assembly on the stand add light oil and spin it with the electric motor until it "smokes freely" can't remember where I read that -- suposedly from Ford, EL
 
Jeff/Illinois said:
How long did Ford run them in at The Rouge when they were built? Were the motors under a load? You've got my curiousity up. They were chucked into an electrical drive mechanism correct, rather than actually running on gasoline?
Click to expand...

I read somewhere that the freshly assembled engines were monitored as to the resistance (load) they exerted against the electrical drive mechanism. It was my impression when I read about the process that they watched the amp draw on the drive unit but I couldn’t say for sure. When the engine’s resistance dropped to a certain level, they considered it ready for installation.
Good Day!
Dave in MN
 
I like to run an engine prior to installation however, I do not idle the engine for long periods of time, and I do not idle the engine at all during the first 15 minutes or so of running. Run the engine at about 1200 RPM or so for the first 15 Minutes varing the speed every so often. This is to be sure everything receives good lubrication including the camshaft.

Be sure the timming is corret. During initial brake in, I run the engine at about 1/2 advance.

Retorque the head after every "heat cycle" and repeat as necessary until the torque does not change. Sometimes it may take 4 or 5 "heat cycles" to get the head fully "seated".

I do not like to run the engine excessively on the engine stand. I would think 30 Minutes or so should accomplish everything you need to do. Rings will seat much faster when you get the engine under load.

Running a "new" engine on a stand is a good idea. Often some problem such as a minor water leak or something like that is easy to correct on the stand then once it is in the car.

My Opinion,

Chris
 
If it was me and i had a stand/radiator set-up I would most surely run it on the stand, at least up to operating temp and 2nd torque on head bolts. Aso if there were any leaks/other issues, now would be the time to address them rather than after it's all hooked up in the car..... JMO
Paul in CT
 
I have run my mill twice in the bare chassis of the car for 20 minutes at a high idle. After that amount of time the entire engine and oil pan are about as hot as they are going to get. I re-torque the head the next day when it's stone cold. I am going to do it once more then I think it's on the road. The only problem so far is a little tear drop on one of the studs.
 
I believe using your test stand is a good idea. I do not have a test stand and just recently started a new rebuilt engine after installing it in my A.

I ran the engine at fast idle for 20 minutes until it was up to operating temperature, shut it down and immediately re-torqued the head as I used a copper head gasket.

On a previous rebuilt engine I used a Snyder head gasket, so after running for 20 minutes I shut it down, let it cool overnite, then re-torqued the next day.

Depending on the type of head gasket you use on your engine is the determing factor at to when to re-torque.

I'm not going to get into torque values as I do not want to start that kind of discussion as everyone has different ideas.

Ron
 
Jeff/Illinois said:
How do you torque the heads at 55 pounds/feet on the water outlet connections without snapping the dog ears while you are doing the rotation? Ease off on those two?

I've broken more than one over the years. Just curious what you guys do.
Click to expand...

The main cause of broken ears is thick paper gaskets, followed by non-flat mating surfaces.

I sand the outlet with abrasive paper on a FLAT surface such as a surface plate or cast iron machine table like a table saw. I check the head surface for burrs or other high spots. Then I assemble using a thin layer of RTV sealant, allowed to cure for 10-15 minutes before installation, and NO gasket. Then torque to the value of your choice or as specified by your head manufacturer.

Joe
 
Engine break-in at the factory was accomplished by coupling the engine to a "water brake", which was actually the power driver to rotate the engine. When the resistance of the newly assembled engine dropped off, the engine was accepted for the next step.
When I overhaul an engine, I prefer to exercise or spin the engine during the various steps of assembly, using a large electric drill as as driver. Lots of oil to the various components during this process is of the most importance.
Wish I had a test stand with gauges for engine analysis, would rig it up with possibly the transmission connected, as suggested, and build up my own type of "Water Brake" using some type of industrial pump.
 
I agree with the previous comments about the use of a stand before installing in the car. My stand has a ratty old radiator and I can run the engine with block sealer, then drain and flush any residual gunk and rust particles out of the block before installing it with new hoses and a good clean radiator.
 
Jeff in Illinois,

I torque the two front head studs and the manifold at 50 lbs., and the rest of the head studs at 55lbs. Guess I've been lucky, havn't broke a water outlet casting in many years.

Ron
 
This may be an interesting side-note. I have a friend with a couple A-powered open-cockpit Pietenpols. The A engines work so lightly in that light aircraft that he can't break an engine in in one, so he puts the engine in a Model A and drives it around for 500 miles, then puts it back in the plane. They cruise at about 1850 RPM and make a pleasant whisper when they fly lazily over.
 
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