[alfa] Proper engine break in

[alfacybersite <acs@xxxxxxxxxxxxxxxxx>]

Steve Moresi brings up one of the main reasons why 'in the good old
days' it was imperative the break in period be slow and painful (for the
driver who wanted to go faster). Really, really paraphrasing what he
said is that the poured / babbitted rods and mains contained thick
sections of lead nor were the tolerances all that accurate. Later when
inserted bearings were used, the tolerances still weren't all that
accurate.

Now, with highly controlled tolerances in the manufacturing process, it
is considerably less of a problem.

I'm sure everyone out there who works on cars has a bearing scraper -
don't they? Waaay last century when I was a mere lad, knew guys who
would run the pee-pee (need to come up with a better term but piss
sounds so crude) out of their Model T's and A's during the week, then
drop the oil pan and rods, pour new babbitt into the rods, then hand
scrape using their trusty bearing scraper and lots of machinist's
bluing. Actually I would hear these stories from the old timers once
they found out my 1950 Riley had / has poured bearings.

Let's accept Steve's theory for the moment. I'm also going to include
that along with precise tolerances greatly improved lubricants have made
vast differences. Funny, but the break in period 'back then' required
the use of 10W oil. Now I believe that is what Honda (and no doubt
others) use as their 'ordinary' oil.

Not too long after I joined this august Digest, I made some rather snide
comments regarding Spicas. Fred's reply began something like, "If your
brain was dynamite, there wouldn't be enough to blow your head off."

Be that as it may, one of the situations I absolutely hate with Spicas
and fresh engines is one needs to get the engine hot before they can
adjust to get the critical 19 mm gap. Since I either silver zinc or gold
irridite virtually everything I can, that means the two Spica rods are
stripped down. Even though I count revolutions before stripping down, it
is always exciting trying to get the engine to start, run well enough to
get hot, then finally start adjusting for 'gap'.

Say what you want, but I'm considerably more concerned about glazing the
rings during this unfortunately necessary period than I am about
spinning bearings when revving a fairly fresh engine.

I do make a point of varying the idle as the engine (slowly) heats up,
but still, I fully agree the rings need Very Aggressive variations in
engine speeds right from the beginning. No, I don't feel all that good
about the other engine parts, but damned if I'm going to pull an engine
apart because the rings wouldn't seat.

Oh yeah, glazing did happen to engines in the 'good old days' but not
all that often since (pretty sure) they all had cast iron rings. It
happened to my Riley engine once - that is the last time an engine's
rings haven't seated in for me.

Biba
Irwindale, CA USA
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided