You.....AGAIN!!? Well, ok!! :)
You will get opinions galore on this so best to follow advice of engine
builder
of course, Mike.....after all he is the one
who built the motor and he is the one
guaranteeing the job. So, in any event,
he is "the man"!!
I have just 900 miles on my new Rivergate 1293. This is a street motor
"planned" on the tight side with respect to
"tolerances". It ran "hot" when new and
is slowly beginning to run "cooler" unless
opened up....so it's still "tight" with respect
to higher rpm's (over 3,000). Also, fuel
economy is getting noticeably better though we've just gone over to "H6"
needles in place of the "AN"'s as we
are beginning to go to 4,500 revs once
in a while and will shortly go higher.
The motor:
is "tailored" for eventual installation of a
Judson blower, so it's static CR is only
8.3-1. It's aluminum head was "cc'd"; it
sports a Cooper "S" cam (510 grind)
"advanced" 4 degrees, 1.5 "rollers" (bushed) and Total Seal rings. The
stock
flywheel is lightened by 5lbs. and the
entire rotating assembly (EN40B crank, etc.) is balanced to "street"
spec.
The engine was built assuming a long
break-in period. It runs normally aspirated
on the stock carb set-up at this point, the normal 1275 dizzy with max
centrifugal
advance being set at 32 degrees utilizing
93PON unleaded. K&N filters are used
in the stock "cans". It has a medium bore
"coated" header running to an RC40 (rear
box only).
Oil and filter were changed at 500 miles
and head retorqued and valves reset to
.018 "cold". The carbs were "retuned"
at that point and leak down test performed; virtually "0" across the
board.
At 1,000 miles we will go through the same procedure but add a
compression
check. The engine uses very little (virtually none) oil. The engine
sports
a magnetic oil sump plug. These work!!
This engine's initial 500 mies were spent
in short (1/2 hr.) drives on suburban
"countryish" secondary roads
(little, if any traffic) with plenty of
cool down between drives (per River-
gate instructions). No "lugging", ever!!
My mechanic did the intial running to break-in the cam properly and I
took it
from there. The engine never smoked.
During the first 500 miles, 3,000 rpm was
never exceeded and throttle opening was
limited to far less than 1/2 throttle.
In the last 400 miles (after the initial 500)I I have gone to 4,500 rpm
maybe 6 or 7
times while consistently using 1/2
throttle during ANY acceleration whenever traffic conditions permitted,
and have taken short drives on limited
access highways wherein 3,000rpm was
sustained for a few minutes at a time in
5th gear (Datsun 5 speed).
The 2nd thousand miles will see a lot
more use of mid-rpm range up to spurts
to 5,000 using 3/4 throttle as mileage
increases beyond 1500. The 3rd 1,000
will include WOT spurts to between
6 and 6.5K. Sustained cruise at ANY given rpm will be avoided 'til we
pass
the 3,000 mile mark.
Oil and filter will be changed at every
500 miles through the initial 3,000 at
which point we expect to see virtually
no "swarf" on the magnetic oil plug.
At 5,000 miles we will go from multi-
viscosity mineral oil to Oil Extreme
Synthetic. We will also go to the
"normal" every 3,000 mile (or 3 month)
oil change schedule.
At this point Mike, the rings are obviously
seated, the engine produces excellent
torque (power) and is extremely "responsive", and smokes NOT!! It uses
virtually no oil in the 500 miles between
current changes. It has one hell of a 'healthy" sound despite being only
an
8.3-1 engine and I attribute this to the
excellent sealing qualities of the Total
Seal rings which "hold" compression
within the combustion chamber far better
than other ring types, as the K&N filters
on each of the crankcase vent "tubes"
show virtually no contamination with
crankcase "blow by" gasses.
You'll hear other ways to break in engines
but removing the least amount of metal
slowly over time (miles) is MY way of
ensuring I get the most bang for MY buck
in terms of long engine life. This is a street motor, not a race motor,
which are
built and broken-in quite differently considering their more or less
constant
and continuous "high load" application.
AND relatively short intervals between
"rebuilds".
Remember that you change oil to remove
contaminents and not because the oil has
lost it's film strength or ability to properly
lubricate (this includes your 25,000 mile
synthetics!!).
New engines "make metal" most in their
initial break-in period and "coming apart"
(usually "age" (mileage) related) period.
During break-in you are removing the
"hills" from metallic surfaces; the more
gently you remove these "peaks" the less
metal will get removed from the "part"
along with the "peak"!! And this spells "longevity" for the parts, all
else being
equal. These metal particles aren't doing
the oil any good as a lubricant; thus the
magnetic oil plug and constant oil & filter
changes every 500 miles for the first couple of thousand miles or so
before
going to a "normal" oil/filter change schedule. This is NOT a
"production
factory-built motor", after all!! We also
"dumped" and washed out the oil
cooler, as well.
Is the above "overkill" or just "cheap
insurance" with respect to your financial
investment? Take your pick!! :)
Oh, incidentally, this "gentle" break-in
technique....does wonders for clutch life,
as well. "Works good, lasts a long time"
all other factors being equal!!
The gearbox is a "new" rebuilt as well.
It's oil got changed at 500 miles as well
and will be again at the second 500; then
once a year.
Long post, huh?? :) "Sopranos" time!!
Cap'n. Bob
'60 :{)
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