break-in procedure

[Mike Arman]

Break-in comments -

1) Don't use synthetic oil at first. It is too slippery, and the rings may never seat.

2) ALWAYS warm up the engine, maybe 30 seconds in warm climates, perhaps a minute in colder areas. 
Important in all engines, moreso those with cast iron blocks since the coefficient of expansion of 
aluminum pistons is greater than that of the cast iron block - if you push it with the engine cold, 
the pistons will expand faster than the block can get out of the way, increasing wear and possibly 
scuffing the pistons and damaging the rings.

Warmup also gives the oil a chance to circulate and start to thin down a bit, and remember you might 
also want to go gently on the transmission because it needs to warm up, too. Don't sit for five 
minutes to fully warm up the engine and then launch with a stone cold transmission . . .

Turbo engines also need to cool down. Turbos run HOT and if you screech to a stop and just shut them 
off, the oil in the turbocharger's center bearing will cook. Idle for a minute or so before turning 
off the key, let the turbo housing cool off and the oil circulate. Mooney advises idling for five 
minutes facing into the wind before shut-down to protect the turbocharger.


3) Change oil and filter at 500 miles, again at 1,000, then at 3,000. If you want to use synthetics, 
now is the time to switch. Most cars are quite happy on any quality brand of dino juice, most 
synthetics seem to be just a way of separating people form their money (like most car waxes), and 
most synthetics are semi-synthetics anyway. If you are nervous about the so-called "lack of quality" 
of plain old motor oil compared to synthetics, look and see what the racers are doing. They run 
their cars much harder than we do, and rebuild them more often. Their engines usually break from 
being overstressed (bent rods, cracked pistons, blown head gaskets), not from oil or lubrication 
failures.

(Ever see the remains of a funny-car engine that has failed? There's a good reason they call it 
"grenaded". These are not lubrication failures. Well, at least most of the spark plug wires are 
still good . . . )

Synthetics were originally developed for jet engines which run a lot hotter, make rather more 
horsepower, and cost fantastically more than cars. Core temperatures on most turbine engines are 
much higher than any car and synthetics don't break down from heat as quickly as mineral oils. Just 
because it says "aviation" doesn't mean it is better, but it does mean it will cost more.


4) After break-in change the oil and filter at recommended service intervals. I read these stories 
about Audis burning a quart of oil per thousand miles and "that's OK". Sorry, if my crappy Honda 
Accord doesn't leak or burn a drop of oil in 7,500 miles between recommended oil changes, something 
is wrong - you can't tell me Audi knows less about engines than Honda or that Audi can't build an 
engine as well as Honda.

5) Too frequent oil changes are a waste of money, but not changing oil is flirting with disaster. 
One of the byproducts of the internal combustion engine is dilute sulfuric acid (water from 
condensation in the crankcase combines with sulfur in the oil), and you need to change the oil to 
get rid of that crap and other contaminants (metallic, chemical, carbon particles, etc.). This is 
especially a problem in cars which are driven around town in cold weather and never really get 
warmed up - the engine doesn't get hot enough to boil off the water. Always remember, oil is cheaper 
than engines - a LOT cheaper.

If you break in your engine even close to properly and change the oil regularly, it will run almost 
forever. If you fire it up and instantly launch stone cold from day one, you'll be looking for 
another engine or another car pretty quickly.

Best Regards,

Mike Arman

90V8Q, and LOTS AND LOTS of other engines, plus 50+ years of hands-on experience with them, from 
.020 model airplane engines through countless mowers, motorcycles of all sizes and flavors 
(including rotary), something like 150 cars, some outboards, and real airplane engines from the 
O-200 all the way up to four engines on a DC-7 freighter which I am *very* glad not to have owned. 
Very glad indeed. I'm sure there were more, apologies to any engines I've forgotten.