Replacing rod bearings, do they have to be broken in?

[1993MTXSHO]

As the title states I am replacing he rod bearings on my 93, what I am wondering is can I replace them and go drive the way i usually do (beating on the car occasionally) or do I have to keep the rpms down and go easy on her for 500 miles or so?

 

[sdpatt]

You can edit your first post to correct the spelling of the subject line.

This Mustangs & Fords article provided some good tips on engine assembly and break-in. Other than spinning the engine without spark or fuel to provide oil pressure and film prior to startup, I would be kind to the new bearings for a few hundred miles just to ensure a low stress break-in period.

 

[Eric VerValin]

Nice to see that part about using regular old oil for break in.. i was wondering myself about using synthetic for the first time.

 

[1993MTXSHO]

Nice to see that part about using regular old oil for break in.. i was wondering myself about using synthetic for the first time.

good point, I am replacing all my seals and the bearings although now that the tolerances of the engine have probably gotten bigger because of mileage it might not be wise to use synthetic, whats everyones take on that, how about a synthetic blend?

 

[SHOZ123]

I see no issues what so ever on using synthetic oil. Especially on new bearings.

 

[1993MTXSHO]

How about on the rings? Would using synthetic cause more oil burning? Maybe ill start with a synthetic blend for 3k miless then switch it over to a full synthetic

 

[Eric VerValin]

another thing i was wondering about is priming the oil pump ? do i need to do this? or will turning the crank by hand do that? Wouldnt turning the crank by hand a few times be enough to coat and seat everything? Or does it require some pressure by turning it over with no spark, as stated earlier?

 

[Axianator]

As the title states I am replacing he rod bearings on my 93, what I am wondering is can I replace them and go drive the way i usually do (beating on the car occasionally) or do I have to keep the rpms down and go easy on her for 500 miles or so?

Personally, I have never found a valid reason for "going easy" on new rod bearings.

another thing i was wondering about is priming the oil pump ? do i need to do this? or will turning the crank by hand do that? Wouldnt turning the crank by hand a few times be enough to coat and seat everything? Or does it require some pressure by turning it over with no spark, as stated earlier?

IMO, the easiest procedure for re-pressurizing the crankcase oil pressure would be to disconnect the DIS module and crank the engine until the oil pressure light has been extinguished. Doing this will build oil pressure within the crankcase by forcing oil through the engine while the lack of spark from the disconnected DIS module will prevent the engine from actually starting.

 

[SHOZ123]

You did pre-**** the bearings when you installed them right?

 

[SHOtime2511]

just to share what i did
i took it easy on my 91 for about 400miles after rod bearings,less than 4K rpm

 

[Rockledge]

Personally, I have never found a valid reason for "going easy" on new rod bearings. .

I'm of the same opinion. I figure that once motor is warm and the oil has flowed for a while, you're good to go.

IMO, the easiest procedure for re-pressurizing the crankcase oil pressure would be to disconnect the DIS module and crank the engine until the oil pressure light has been extinguished. Doing this will build oil pressure within the crankcase by forcing oil through the engine while the lack of spark from the disconnected DIS module will prevent the engine from actually starting.

IMO it would be a good idea to also push the gas pedal to the floor while cranking to ensure that the fuel injectors are not squirting fuel and potentially flooding the cylinders.

 

[Axianator]

IMO it would be a good idea to also push the gas pedal to the floor while cranking to ensure that the fuel injectors are not squirting fuel and potentially flooding the cylinders.

Excellent point. Thanks for getting my back.

 

[1993MTXSHO]

woah wait pushing the gas pedle to the floor cuts the fuel injectors on new cars?

 

[SHOZ123]

Yes indeed. It is how you clear a flooded engine with FIs.

 

[Rockledge]

woah wait pushing the gas pedle to the floor cuts the fuel injectors on new cars?

While cranking, yes.

 

[1993MTXSHO]

sweet never knew that im more used to carbs