Engine break in prep and video

Discussion in 'Street/strip 400/430/455' started by Jim Weise, Oct 13, 2010.

  1. Jim Weise

    Jim Weise 1000+HP

    Originally posted as a reply to an issue, but at the request of some board members who saw it, I have edited it and reposted it here.

    Engine break in prep and procedures.

    Because this comes up from time to time, here are a few pointers, and a video.

    Successful new engine break in, starts when assembling the engine.

    I use a heavy assembly lube, such as Clevite's "bearing guard" on all engine bearings during assembly, including the cam bearings.

    Lifters are installed with just a little oil on the sides, but with the cam break in lube on the bottom. Soaking the lifters in oil, makes it impossible for the cam break in lube to adhere to the bottom of the lifters. Do not soak or "pump up" the lifters manually.

    The valvetrain was setup and preloaded/lashed properly.

    The oil system was primed

    The distributor was installed and timed close enough to start.

    The carb was checked for jetting, and set close enough for initial startup.

    Then, at the dyno shop, the timing was checked by just turning the engine over briefly, with the ignition system on but no fuel in the carb, so it won't start, until we are ready. But it is verified the timing is close, and the distributor is in correctly.

    Then, the carb is filled with fuel, via the electric fuel pumps, the float level is checked, and needle/seat sealing confirmed.

    At that point, we go to the vid..

    "" f

    Now, what's happening here is simple

    Immediately the engine is brought up to 2000 rpm

    timing is checked and set at 30*, which is where I set all NA engines to start with at break in.

    After a quick glance up at the A/F ratio meter in the cell, I see it's running lean, so I do a quick check for vacuum leaks.

    No vacuum leak is seen, so the carb is adjusted richer, via the 4 idle mixture screws, and brought to right around 12.5 to 13-1 A/F ratio. Not too rich, and not too lean.

    Temps are checked with an non-contact thermometer at the back of each cylinder head, to insure water flow and even warm up.

    A small leak on one of the external water lines (this is a filled block engine) is noted, Ron hands me a wrench to tighten a hose end a touch.

    At about 3 1/2 minutes in, Ron notices the header primary pipes are glowing, he asks me what compression the motor is.. this one is only 8-1, as it's actually set up for a Supercharger, and because of the low compression, we compensate for inefficient fuel burn in the cylinders, with another 4-6 degrees of timing. The engine responds to the extra timing, and the headers stop glowing.

    Low compression engines, can glow the pipes, from the excess fuel burning off in the exhaust and headers. It's worst with a STG 2, due to the very short exhaust port.

    This is not something I have ever seen in a 10-1 or higher engine. But be aware, headers glowing is never a "normal situation". In a low compression engine like this, you might have to bump the timing to burn the fuel completely, but this is done only after your sure that your A/F ratio is correct.

    Typically, glowing headers indicates an engine is lean.
    A word on Q-jets: Typically these carbs are lean and break-in rpm. The carb was not really designed to run at this speed, with the choke open, and no load on the engine- To allow for break in, it is recommend that you close the choke plate slightly, to richen the mixture. Pretty simple here-- just close the plate until the engine speeds up.. if you go too far, it will start running poorly. Then you can use a small chunk of duct tape, between the choke plate and the back of the air horn wall, to hold the plate in position.

    In our video here, notice thatat no time is the engine ever allowed to idle. The higher oil pressure at above idle rpm, and the splash lubrication provided by oil coming off the connecting rods, is all that lubricates the cam, during the critical break in phase. All adjustments and tweaks are made with the engine at that rpm, and two sets of eyes are on it, looking it over.

    If you encounter a problem that can't be fixed easily, then quickly bring the motor back to idle, and shut it down. Once the problem is repaired, then start it back up, and get it back to break in rpm immediately.

    This was just the first 4 minutes, but the rest of the vid is pretty boring, as it's just another 15 minutes or so of watching it run. Everything need for a good break in, was done either back at the shop, before it was started, and then right after start up.

    That first 5 minutes is the most critical time in an engine's life.

    Last edited: Aug 25, 2017
    446370 likes this.
  2. DaWildcat

    DaWildcat Platinum Level Contributor

    Thanks for the good info.

    At some point does the dyno operator start a pre-programmed cycle from low to higher rpms and back again for the sake of piston ring health?

  3. Ragtop 455

    Ragtop 455 Atlanta Driver...

    Very informative stuff here..I appreciate it...
    A question, though. As I have my engine coming out this week and I'll be going through it to replace the rings and the rear main seal, I need to understand the valve lashing process a bit more.
    I'll not be changing cams or lifters, and the lifters are already full of oil.
    My heads are milled .040 ( intake .070) and so I use adjustable pushrods.
    Can you re-educate me on this procedure so I do it right the first time?
    Thanks again.

    1970 Skylark Convertible
    455 engine is a 1973 Vin U
  4. Jim Weise

    Jim Weise 1000+HP


    Later in the break in, we will cycle the engine a bit between 2000 and 2500.

    But real ring break in happens on the first couple pulls. It takes full load cylinder pressure to really seat the rings.

    Typically, we will see 5-10 HP increases, touching nothing else, in the first 3 pulls or so. This is due to ring seal increasing. When the motor will repeat, then it's time to get into the tuning.

    A lot depends on the particular type of rings, as well as the cylinder wall finish. My typical stuff, with 1/16 compression Hastings Racing rings, breaks in completely by the 3rd pull.

    I recently dynoed a motor with Perfect Circle Moly rings.. that motor took 5 pulls to come in, and picked up almost 25 HP. That's unusual, I attribute it to cylinder wall finish of that particular engine, as well as the 5/64 compression rings, required by the Speed pro Pistons. It was one that my customer worked with a local machinist with, for machining and parts. But it did come in, and repeat, just took a little longer.

    But again, you won't really seat the rings, until it tugs hard against the water brake.

  5. Jim Weise

    Jim Weise 1000+HP


    If you had no valvetrain issues or noises before, and your cylinder heads had consistent tip heights, and you use the same thickness head gaskets, you should be fine. Just drop the pushrods back in.

    If you had issues and need to re-adjust.. assuming you have hydraulic lifters.

    1. Do it with the intake manifold off, so you can see the lifters. No need to confuse yourself with firing orders, or cylinder sequences.. just look at the lifters as you rotate the engine.. once the intake lifter follows the cam lobe back down to the base circle, turn the engine another 10-20* (clockwise) and adjust that cylinder. Then watch to make sure that the next cylinder in the firing order is closing the intake as you turn the engine over, and repeat.

    As you look at the engine from the front, the pattern for the lifters is Exhaust, Intake, Intake, Exhaust, Exhaust, Intake, Intake, Exhaust.

    And except for the outer 4 exhaust valves, whose cam lobes are hidden by the block, you can visually look at the cam, with the intake off.

    Putting the intake on, and then adjusting the valves, makes more work and thinking than is required here.

    2. Once you are certain that you are on the base circle, then adjust your length until you achieve no freeplay, and then lengthen the pushrod approximately 1 turn, to achieve .030 to .045 of preload. Inspect the lifter cups to insure they are pushed off the wire retainers approximately that amount.

    Solid lifters adjust the same way, except that you allow a specified clearance in the valvetrain, by using feeler gauges between the rocker and the valve stem.

    matt68gs400 likes this.
  6. arden_dean

    arden_dean Well-Known Member

    good stuff thanks
  7. gsman

    gsman '67 GS 400

    Jim, Would you mind giving me the link to your video? I can't seem to make it work from your thread.


  8. stg2NW

    stg2NW Well-Known Member


    STAGE-2 TORQUE STAGE-2 Buick "482 Stroker" soon!

    Mr. Weise ... "YOU ARE KING!!!!!"

    I honestly appreciate this video and all associated with it.

  10. DaWildcat

    DaWildcat Platinum Level Contributor

    Oil change after break-in came up in this thread: http://www.v8buick.com/showthread.php?253107

    I have always changed oil and filter after flat tappet cam break-in as I mentioned in that thread.

    Would love to hear thoughts from others.

  11. Drachen

    Drachen Well-Known Member

    I am having the 455 of my 1970 Wildcat rebuilt - new rings, valve seals, bearings, gaskets, etc -
    but keeping the original block, heads, pistons and other moving parts. This is strictly a road
    car and will not be raced (unless of course some rice-boy in a Civic wants to try his luck at
    the red light... :) )

    To the best of my knowledge the shop doing the rebuild does not have a dyno. After reading
    this post, I do plan on asking what procedure they will be using at first start-up, so thanks
    for the info.

    One question though - what would be the proper method to break-in this rebuilt engine?

    I've heard that the best method is a 10-15 mile drive while varying throttle position and
    then shut-off/cool-down for the first run, followed by progressively longer rides up until a
    total of 200 miles or so. After that, a complete oil and filter change and then another
    500 miles of the same procedure, followed by a second oil change.

    This info was told to me many moons ago, so I don't know if its accurate or not.

    Would appreciate any insight.


  12. Jim Weise

    Jim Weise 1000+HP

    Before the advent of Plasma moly coatings on compression rings, long "break in " periods were required, as you suggested. 200 to 500 miles of light throttle, variable throttle input driving was required.

    These days, the only thing we worry about really is initial break in, with a flat tappet cam. That is critical to get the engine started quickly, with a minimum of cranking. Then run the engine for 20 minutes, at 1800-2200 rpm, while maintaining less than 210* water and oil temperature. If it gets hot, bring it down to idle and quickly shut it off, cool it down, then continue the process. Do this as many times as it takes to get your 20 minute cam run in.

    On the road, we need cylinder pressure to seat the rings. I suggest several part throttle "test runs" to insure that all your settings are correct, there is no detonation or fuel issues, and then two to three WOT runs from a 10mph roll to 75mph..

    Then drive it normally, all break in has now been accomplished.

    Two things are critical for success.. a good plasma moly ring set with proper cylinder wall finish, and the correct, high zddp, low detergent break in oil. I highly recommend Joe Gibbs BR30. It's simply not possible to spend too much money on break in oil.

    Run it for 500 miles, normal driving, and then change it out for whatever oil your going to run after that.

    Be aware. there are still $60 plain cast iron ring sets available.. stay away from these. Use Quality plasma moly coated, ductile iron top compression rings only..

  13. Drachen

    Drachen Well-Known Member

    Thanks for the advice! I will be having a conversation with my shop tomorrow.

    Fortunately for me, I am only a 10 minute drive to Summit Racing.:3gears:

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