Proper engine break-in procedures
Jefferson Bryant - October 03, 2013 10:00 AM
1 The Easy-Run stand has a lot of options, but everything is modular, so you can add on as you go. Plus the unit can be field stripped and set upright for storage.
2 We bolted a flywheel to the 302; you have to be able to start it.
3 We had two bellhousings, one for an auto and one for a manual. We used the manual housing to match up to the flywheel.
4 The engine was positioned over the stand with the hoist. The motor mounts on the stand are adjustable and are secured with clevis pins.
5 You don’t want the motor to slide back and forth on the motor mounts, which are universal, so the extra space was taken up with washers.
6 We used an Ingersoll-Rand cordless impact to make quick work of all the bolts. The bellhousing mounts are heavy straps with multiple holes.
7 The bellhousing straps connect to a round bar that sits in a V block on the base of the stand. There is an adapter for this that works with automatic transmissions.
8 Monitoring the engine is critical for a safe break-in. The Easy-Run comes with mechanical sensors for oil pressure and temperature. You can always convert it to electrical if you wish.
9 We filled the pan with Royal Purple Break-In Oil to ensure the flat tappet cam would be protected.
10 Prime the oil pump with a drill and a priming tool. Fords are easy; you just need a long socket for the pump drive rod. Chevy and Mopar engines require specialty primer tools. Rotate the crank a few times to ensure the bearings get lubed up.
11 The instrument control panel has everything you need. The mechanical oil pressure gauge showed over 45 psi with just a corded drill.
12 Next, we pulled the #1 plug and set the piston to top dead center of the compression stroke. Then we stabbed the MSD distributor and set the base timing.
13 The electrical connections were next, the block is grounded straight to the OPTIMA battery we used on the stand. The stand even has a nice battery tray.
14 The stand has a mount for the coil and uses simple alligator clips to make easy connections.
15 Underneath the radiator is a five-gallon fuel cell. The Easy-Run comes with inlets/outlets at all four corners on the radiator, so that it will work with any engine.
16 Another really cool feature of the Easy-Run is the throttle control. The cable-actuated throttle has threaded stop that can be used to maintain rpm and/or rpm range.
17 We bolted a set of mufflers to the headers to quiet it down a bit. Without them, we may not have heard the lifter issue when it first popped up. ￼For Your information:
So you finally finished rebuilding the engine for your muscle car. All the bolts are torqued, the valve covers in place. Now what?
The typical answer is to drop it between the frame rails, hook it up and go. Not so fast cowboy, there is a little more to it than that. Every fresh build needs to be broken in. There is a process for running the engine for the first time to set the engine’s wear patterns. This is the most critical moment in an engine’s life, and just like impressions, you don’t get a second chance.
Whether you choose a run stand or install it in the chassis, the process of breaking in an engine is the same. However, there are some very real benefits to using a run stand. A run stand allows you to break in and test the engine without ever having to set it in the car. If something breaks, the repair process is much simpler. Other uses for a run stand include tuning, parts testing and even secure engine storage.
The basic procedure for breaking in an engine starts with having everything correctly installed and ready to start. Don’t even think about firing up the engine if you do not have proper gauges monitoring the vitals: oil pressure, water temperature and rpm are the three most important stats you need in this process.
The tach is your guide for the run; you need to set the rpm from 2,000 to 2,500 for the first 20 minutes of the engine’s life. Don’t let the engine idle. This is most important for flat-tappet camshafts. Roller cams are nowhere near this critical; they simply do not have the friction that a flat-tappet cam sees.
The cam lobes are not the only parts being broken in. The rings, bearings, valve springs, oil pump, all of these items are being run for the first time in most cases so it is important to follow the procedures. The first 20 minutes of run time begins the ring seating process by smoothing out the minute edges on all the machined parts. One of the key ingredients to all of this is proper break-in oil. Modern break-in oils have more ZDDP and other additives to protect virgin metals during break-in. Regular engine oils have been regulated by the EPA to remove these protective elements that a new engine needs.
We recently rebuilt a Ford 302 with a flat tappet cam for a ’65 Mustang. While we could have just dropped the engine into the car, we wanted to get it tuned in and ready to go so that we wouldn’t have to break our backs working over the fenders. This would also give us the opportunity to address any issues should they arise.
When our Easy-Run test stand arrived, it was clear that this was a serious piece of hardware. All of the components were well designed and the assembly was straightforward. You can even mount an automatic transmission on it if you don’t have a manual-style bellhousing.
After the 302 was set up on the Easy-Run, we fired it up. Everything was going great until we heard a faint tap. Suddenly it got louder. Oil pressure was fine, but the engine developed a miss and we shut it down. After some diagnostics, we determined that a lifter had failed.
If the engine had been in the car, we would have had to pull it out, as the final diagnosis was junk in the lifter oil galley that filled the driver’s side lifters, keeping them from bleeding off. The only solution was to tear the motor down and clean up what was supposed to have been done before the assembly in the first place.