correct motor break in after rebuild

[pw520a 19]

Hello, I am looking for advice on how to properly start for the first time and break in a freshly rebult 390, I am sure it is probibly the same for any size. I have been told I should run it at 3,000 rpm for 20 min to break in the cam, Does that sound right? What weight oil ? I was told there is a special tool you hook to your drill motor to circulate oil before starting. Any advice would be appreciated. Thanks Gary

[coz 108]

Stock or performance? Hydraulic or solid lifters? That will help select oil and if you need to even perform a break-in routine.

 

Yes, you can prime the oil pump by pulling the dizzy and inserting a long socket/extension in. Not sure what size socket though... Been years since I had to do that.

[pw520a 19]

It has been rebuilt stock,except for alum intake and edelbrock carb. it has been sitting for about 18 months since rebuild.

[jholmes217 65]

Hello, I am looking for advice on how to properly start for the first time and break in a freshly rebult 390, I am sure it is probibly the same for any size. I have been told I should run it at 3,000 rpm for 20 min to break in the cam, Does that sound right? What weight oil ? I was told there is a special tool you hook to your drill motor to circulate oil before starting. Any advice would be appreciated. Thanks Gary

 

You may get many different answers to this one. Here is what the pro engine builder told me after I picked it up from him when he was done with the machine work: You will definitely want to prime the oil system. This link goes to a product from Milodon that I use. http://www.milodon.com/oil-system/primers-restrictors.asp

If you have hydraulic flat tappet lifters, you will want high zinc oil. I use Royal Purple engine break in oil http://www.summitracing.com/parts/RPO-11487/. Pour the oil across the rockers with the valve covers off and also fill the oil filter before putting it on. Once you are at capacity (probably 5 quarts,) prime the engine with using the instructions with the Milodon primer and drill. Spin it until you see oil circulating back into the valve train, then put your valve covers on. Chec for oil leaks. Top off all other fluids. Auto tranny cars might have to wait to get completely topped off with tranny fluid until after the 1st 20 minutes. Make sure you have your timing and your carb set as close as possible before you fire it up. Once the engine fires, get it up to 2,500 rpm and keep it there for 20 minutes. After that, dial in the timing and carb and then take it for a 40 minute ride, and vary the rpm a lot to help seat things. Stop frequently and check for leaks. Keep the RPM below 3000 for the 1st 500 miles. After 500 miles, change the oil, but use the break in oil again. Once you hit 2500 miles, you can start using regular oil (but use a zinc additive or use a special oil for our old cars that still has zinc. It's pretty much broke in at 500 miles. Check the filter and oil for signs of metal and water.

 

I'm sure others will chime in also, but they will probably be close to this. Have I missed anything guys?

Edited February 19, 2011 by jholmes217

[schultzy69 10]

You may get many different answers to this one. Here is what the pro engine builder told me after I picked it up from him when he was done with the machine work: You will definitely want to prime the oil system. This link goes to a product from Milodon that I use. http://www.milodon.com/oil-system/primers-restrictors.asp

If you have hydraulic flat tappet lifters, you will want high zinc oil. I use Royal Purple engine break in oil http://www.summitracing.com/parts/RPO-11487/. Pour the oil across the rockers with the valve covers off and also fill the oil filter before putting it on. Once you are at capacity (probably 5 quarts,) prime the engine with using the instructions with the Milodon primer and drill. Spin it until you see oil circulating back into the valve train, then put your valve covers on. Chec for oil leaks. Top off all other fluids. Auto tranny cars might have to wait to get completely topped off with tranny fluid until after the 1st 20 minutes. Make sure you have your timing and your carb set as close as possible before you fire it up. Once the engine fires, get it up to 2,500 rpm and keep it there for 20 minutes. After that, dial in the timing and carb and then take it for a 40 minute ride, and vary the rpm a lot to help seat things. Stop frequently and check for leaks. Keep the RPM below 3000 for the 1st 500 miles. After 500 miles, change the oil, but use the break in oil again. Once you hit 2500 miles, you can start using regular oil (but use a zinc additive or use a special oil for our old cars that still has zinc. It's pretty much broke in at 500 miles. Check the filter and oil for signs of metal and water.

 

I'm sure others will chime in also, but they will probably be close to this. Have I missed anything guys?

Nope that pretty much everything you need to know.....But i heard that during the first 20min start you should change RPM's every five min or so staying between 2000 and 3000 rpm. never go below 2000!

[pw520a 19]

Thanks for the info it was much appreciated, Gary

[gsxrken 21]

Two other points-

it's not a bad idea to bump the motor by hand while you are priming, just to get all the crank's oil passages getting all the bearings.

 

The other thing to watch for is how hot the engine gets. Have a good gauge. If you have any suspicions about it running hot (.060 overbore, old radiator, or poor fan shrouding), trickle cold water from a hose constantly into the top of the radiator and leave the petcock open that amount. This can help with the 390s and their weird radiator cap deal that can trap some air, too.

You don't want to shut down due to heat in the middle of your break in.

[Burn 14]

I recently broke-in my engine using the following Lunati cam break-in procedures: (Note: I used Royal Purple Break-in oil during the break-in and for the first 250 miles. After that I switched to RP 10w-40.)

 

Lunati recommends “pre-oiling” your engine prior to start up. Failure to do so will result in premature parts wear and possible cam failure. Dry cam lobes and lifters will wear out immediately upon start up. Lunati will not warranty cams that have failed due to improper break-in, lack of lubrication, or dry start ups. Oil pump primer tools are available through most major auto parts suppliers and speed shops.

 

We have found that utilizing straight 30 weight, non-detergent motor oil works best for initial start up and cam break in. Switching to a multi-grade, premium quality oil for your climate conditions is acceptable after the first 500 miles of engine operation. DO NOT use synthetic or synthetic blend oils prior to the first 5000 miles of engine operation.

 

Lunati recommends filling the oil filter with fresh oil in addition to the crankcase prior to initial start up.

 

Filling the carburetor float bowls, or priming the injection pump will facilitate quick engine start up. This prevents cam and lifter wear during the initial engine firing. Once the engine fires, Lunati recommends setting the throttle RPM at 2000-2500 for the first 20 minutes of run time. After the first 20 minutes, we suggest increasing the engine RPM in increments of 500 RPM for 1 minute at a time up to 3500. After reaching 3500 RPM and maintaining for one minute, begin to decrease RPM in increments of 500 RPM for 1 minute at a time until the engine is back down to 1000 RPM. Once this is accomplished, your Lunati cam and lifters have successfully completed their initial break in run cycle.

 

In the event your engine develops a problem (overheating, fuel leak, etc.) shut the engine off immediately, let it cool down, repair the problem and resume your break in procedure.

[bigperm2 10]

Like Jholms said, you will get a bunch of different answers to this. The zinc additive is important and you should use it. A good conventional diesel oil like Rotella T (as of a few years ago) still has a little zinc in it, but don't run it permanently. My personal preferance is straight weight 30, it will be thick cold. For FE motors, you should prime the motor with the valve covers off, to make sure you are getting oil to the top. Oil gets to both heads through one of the rocker pedistals, and the distributor does not need to be in to get pressure to the top (some motors need the distributor in to get pressure to both sides of the motor.) You can use a 5/16 deep socket with extensions... set your drill backwards to counterclockwise.

 

I prefer to break in motors with water only, since over 50% of the time, it boils over. Just be cautious if you leave it overnight in a below freezing garage before running the proper mix.

 

The 20 minute breakin at 2500ish RPM seems to be the norm, and that is what I shoot for, but don't loose sleep if you have to shut it down and adjust something, and start it back up. Change your oil after... The first startup on the filter can fill the filter with enough crap to bypass the filter (very bad, might have destroyed bearings on an engine for me once!)

[02Lightning 10]

Don't use a cordless drill to prime it either. I had smoke rolling out of mine.