smash fascism

I know this has been covered but wondered if openions have changed.

Runnerdown

Verify good oil pressure, no leaks and then run it hard. I am not talking out my ***, this is what I do and it works great everytime.

ralli

heres a site that im sure has been posted before.

http://www.mototuneusa.com/break_in_secrets.htm

shorto85

Drive it normally

SOHCD16y8

speaking from experience, break it in HARD

Scott_Tucker

This is quoted from the book <u>ENGINE SERVICE</U> by Gary Lewis except where noted. Gary is a teacher at DeAnza College in Cupertino, Ca.

"ENGINE BREAK-IN:

For years it was common practice to break in engines on lightweight, non-detergent oil (detergents can turn into ash and leave deposits behind the piston rings, it's possible this is a property of Honda's break-in oil but I am not sure - Scott's comment). Currently, it is recommended that the crankcase be filled with an oil having the service rating intended for the engine. This recommendation is based on the fact that many emission-controlled engines develop tremendous heat, and oil with a lesser service rating than specified will break down and not maintain normal oil pressure and lubrication. This oil breakdown can lead to early failure in a new engine. Also, oils with lesser service ratings do not provide adequate scuff protection for the camshaft (Cam break-in is critical. It is imperative that you use the break-in method recommended by your cam grinder for that cam. Some cams have been 'Parkerized' which is a zinc-phosphorus coating that adsorbs oil which helps protect the lobes by releasing oil if the metal reaches a critical temperature - Scott's commment)

The engine should be run at a high idle speed for the first few minutes of operation to ensure adequate oil throw-off onto cylinders and oil circulation to all moving parts. The vehicle should then be run on the road for the initial seating of the piston rings. This is done by cycling the engine speed: first accelerate, and then decelerate repeatedly until oil smoke is no longer apparent at the exhaust pipe (a catalytic convertor may hide any smoke - Scott's comment). Gas pressure forces compression rings against the cylinder walls on acceleration, causing seating to take place more rapidly. On deceleration, oil is drawn up onto the cylinder walls, owing to vacuum above the piston, thus preventing cylinder scuffing or scoring during cycling. The engine idle speed may be set to specifications after cycling the engine. (The cross-hatch angle and stone grit used for final honing is critical to proper ring sealing. If your machinist never asked you what type of rings you are running you may have sealing problems. Consult the ring manufacturer for cylinder wall specifications - Scott's comment)

Driving at high speeds may overheat new bearings, which are relatively soft and deform easily. This softness is necessary to permit bearings to conform to the shape of housing bores and rotating shafts. The bearings conform to shape and harden after the first several hours (500 miles) of engine operation and are not as easily damaged. Long periods at idle should be avoided because oil throw-off onto cylinder walls is reduced. Overheating may also occur during long periods at idle.

It is generally recommended that the owner drive the car “normally" during the first 500 miles. High speeds and long periods at idle are to be avoided. The owner must also be cautioned to watch engine temperature indicators, because new engines tend to run hotter because of increased friction and efficiency.

The oil level in the crankcase must be checked frequently during break-in. It is normal for a new engine to use 1 or 2 quarts of oil during break-in, especially if driven at highway speeds. Be careful because the engine may use no oil when driven around town and then use 1 or 2 quarts very quickly when driven on a long highway trip.

FOLLOW-UP SERVICES:

The oil and oil filter should be changed after break-in (right around 1000 for a street car in my opinion - Scott) because abrasives and metallic particles picked up during engine service work free during the break-in period. Cylinder heads and intake manifolds should also be retorqued after break-in to compensate for changes in gaskets caused by heating and cooling cycles.

Never, ever use synthetic oil to break in an engine. Synthetics do not allow enough friction for the rings to break-in and thus will not seal properly. It's OK to use it at the first oil change. Changing your oil and filter every 100 miles for the first 1000 will not accomplish anything positive. - Scott's comments

Carburetor (final tuning - Scott) adjustments are generally required after break-in. Choke operation changes after rebuilding the engine because the exhaust passages used to heat the choke are clean and possibly work normally for the first time in years. Idle speed keeps increasing during break-in because internal friction in the rebuilt engine slowly diminishes. Fuel mixtures are affected also because ring seating changes intake manifold vacuum.

Valves will recess slightly into valve seats during break-in. Because of this recession, valve adjustment should be rechecked in all engines without hydraulic lifters. Re-adjusting valves with hydraulic lifters will not be necessary because plunger travel will allow for valve recession. "

I have been using the methods described here for 16 years with no problems. A couple final points: If you drive your car too conservatively, the rings will not break-in and you will have sealing problems in the future. Also, if your car is excessively rich because it is not tuned properly you run the risk of having the excess fuel condensing on the cylinder walls and washing all the oil off them (obviously not good) and possibly filling your oil pan with fuel.

-Scott Tucker

.1type.

Chris22215

91civicDXdude

that sounds like an old schooler. i was under the assumption that bearings need no break in, and that valve seats needn't be hardened since the days of unleaded fuel

Scott_Tucker

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91civicDXdude &raquo;</TD></TR><TR><TD CLASS="quote">that sounds like an old schooler. i was under the assumption that bearings need no break in, and that valve seats needn't be hardened since the days of unleaded fuel</TD></TR></TABLE>

Bearings do break in, it's not something that's really ever mentioned because there is not much you have to do about it, it is just a natural process. The tin/lead babbit layer on the surface of the bearing work hardens as mentioned by Gary Lewis in his book. Another function of the babbit layer is to absorb small metal particles so they don't score the bearing journal. In other words, small particles, usually left over from machining and assembly, will imbed themselves into the soft babbit layer rather than staying in the oil film between the bearing and the journal where they could possibly damage the journal. Valves should always be adjusted after the engine is broken in. Valves seats are always hardened in modern engines. Although they might not be far out of adjustment, even a small variation in valve clearance in a mechanical (meaning not hydraulic) valvetrain can vary the seat to seat duration of the cam from cylinder to cylinder and possibly cause a rough idle (not to mention high valve seating velocities at high RPM if they are too loose).