Author: Dave Williams; dlwilliams=aristotle=net
We've already done a rebuild on the original 283 for Tommy's '65 Impala SS. Then we did a thumping 311 inch 283 stroker. Now he has a 383 stroker, for a hundred cubes more than he started with...
Here we begin - a crusty old 350 from a 1975 Chevy van. One of the last of
the heavy blocks before GM started their weight loss program.
The engine was essentially complete, with the original intake and 6-quart
truck pan, which will be used in the subsequent buildup.
This particular engine had essentially died of old age. The previous owner
had changed the oil every now and then, so it wasn't the slimer it could have
been.
After everything unbolts, you get to drive the cam bearings out and then
remove the freeze plugs. Typically, about half the plugs will come right out,
and the rest will require much hammering, pliering, chiseling, and cursing.
Once the freeze plugs are out, you can tilt it on its nose and run a 3/8"
drill through the square head oil plugs in the back. You can play with the
torch, wax, penetrating oil, square head impact bits, and other tools, but
they'll take longer, and about half the time you'll wind up drilling the
[deleted] plugs out anyway.
Hammer a cape chisel into the drilled hole, turn with wrench. EZ-outs of
various sorts will just wedge the tapered pipe plugs immovably into their
holes.
Three foot long, 5/16" steel rod pops the front oil plugs out from the back.
Now the block goes into the tank for its first cleaning.
The much cleaner block with the brand new 3.75" stroker crank. The pan rails
and cylinder skirts are ground to provide .060" clearance for the rod bolts.
The block had to be align bored, which isn't very common for a Chevy. I guess
it had seen a hard life. All the naughty bits got cleaned up and balanced
afterward.
Since this is a truck motor that will get run hard on cheap gas, it got a
short fill of Hard Blok to stabilize the bores.
Another view of the block filler. The trick is to mix it liquid enough to
pour through a large mouth funnel; the first few times I used it, I didn't use
enough water.
The buyer wanted new rod bolts. The ARP bolts only cost a few bucks more than
stock replacements.
Resized rod, new piston, rings are already gapped, bearing clearances checked.
We're ready to rock and roll now.
And shortly after, all right pistons are in. Quench side is to the intake
manifold. These are 8.5:1 pistons. For a few per cent peak power loss, the
lower CR will make it much easier to tune and more tolerant of bad gas, hot
weather, or hard going pulling a trailer through the mountains.
Cam degreeing time again.
Offset bushing kit. The 4 degree bushing is the one I wanted.
The dowel hole in the crank sprocket has to be enlarged to take the bushing.
The retaining bolt holes also have to be enlarged or slotted.
And here we are, with the cam advanced 4 degrees. The bolt lock plate is
necessary to keep the bushing from falling out. Chevy used them on 265s and
some 283s, but dropped the lock plates about the time the 350s came out. New
Grade 8 bolts came with the kit. I torqued them with Loctite 252 and bent the
locking tabs over.
Now I screw the fancy adjustable piston stop in... it won't work with the deep
dishes in these pistons, so I had to dig out the extended stop I use for
Fords, which have a shallower plug angle. The crank is gently turned until
the piston contacts the stop.
That's a brand new 400 balancer. There's a brand new 400 flexplate on the
other end.
We make a mark on the balancer, then turn the engine the other way until it
hits again.
Halfway between the two marks is Top Dead Center. This one was pretty close.
I filled the groove in the balancer with paint, and marked TDC and 8 Before on
the timing tab.
This engine got brand new 1.6:1 rockers on the intake side. I used stock
1.5:1 rockers on the exhaust side. I always dress any dings or dimples off
with the disc sander. Anything more than a faint impression, easily sanded
off, goes into the metal recycling bucket.
Adjusting the valves. I had a Compact Flash chip decide to freak out and lost
all the pictures of the heads. These aren't the heads that came on the core
engine; they're a set of thickwall 993 open chamber heads that I had pocket
ported years ago for another engine, which was also a 383. They had come back
as trade-ins for another pair of more seriously ported heads. These got new
bronze guides, brand new 2.02/1.60 stainless steel valves and pocket rework to
accomodate them, got decked true on the head machine, Magnafluxed, three angle
valve job, new Z-28 290# valve springs, Perfect Circle seals, yadda yadda.
This is the oil filter bypass for a small block Chevy. Its stated purpose is
to open and allow oil to circulate if the filter gets completely stopped up.
It has a very weak spring, which lets unfiltered oil bypass the filter when
the engine is running. I knocked the spring and disc valve out and used a
3/8" NPT pipe tap in the hole.
Now a 3/8" hex head pipe plug and Loctite eliminate the bypass. This has
proven safe even in subzero weather as long as you're not running 50-wt
sludge. Theoretically, with thick enough oil, cold enough weather, and a
heavy foot, you could either blow the filter off the block or strain part of
the pump drive system, but I've never had it happen... and it makes me happy
to know *all* the oil getting to the filter is going through it instead of
around it. The rear main on the small Chevy runs unfiltered oil, a holdover
from the days before Chevy cobbled a filter onto the small block, which
originally had none. That's why there are so many strange turns in the oil
path of the small Chevy.
Melling M55HV high volume pump.
The new pickup tube being driven on with my homemade tool. Beats the heck out
of trying to do it with a chisel or screwdriver.
Another shot of the tool.
Now we clay the pickup and trial fit the pan.
When the pan comes off, the smashed clay gives us the pickup clearance. We
were right at the recommended 3/8", so I didn't have to tap the pickup up or
down to adjust it.
And the pan goes on for real... the assembled engine gets a final coat of
Dupli-Color Plum Purple when it's done. The purple was a joke on the buyer,
but most of the people who saw it liked it.
Fired up first try, spent two hours on the run stand, cool as a cucumber. The
214/214 cam is dead smooth in an 8.5:1 383. The oil came out clean, it's
ready to ship.
M A X I M U M O V E R D R I V E R A C I N G E N G I N E S
383 Chevy stroker for Tommy Wilson
completed 04/03/2003 (complete engine)
4.060 bore (+.060)
3.750 stroke (+.250)
388 CID, 6365cc (6.4 L)
72 cc combustion chambers
26 cc dished pistons
3 cc .015 deck
7.3 cc .035 gasket
------
108.3 cc clearance volume
796 cc swept volume
+ 108.3 cc clearance volume
--------
904.3 cc total volume
904.3/108.3 = 8.35:1 CR
warranty: if it breaks, you get to keep all the pieces you can find
heads:
993 heavy-wall castings
pocket ported
new 11/32 valve guides
SSI 2.02/1.60 one-piece stainless steel valves, single groove
3-angle valve job
chased all threaded holes
clearanced intake pushrod holes for 1.6 rockers
.080-.090 exhaust seats
.060-.070 intake seats
Perfect Circle seals and steel umbrellas (no O-rings)
.001-.0015" guide clearance
new Z/28 valve springs, 190# open
block:
350 Chevy, two bolt main
bored .060 over, honed #400
1/3 fill Hard Block
new cam bearings, Dura-Bond CH-8
new freeze plugs
clearance bores and pan rails for stroker crank
chase all threaded holes
align honed mains
new lower dipstick tube
pistons:
Dynagear 1383-P-60, .060-over
26cc D-shaped dish (checked)
no pin offset
1.43" pin height for 5.7" rod 383
rings:
Hastings 4.060", 5/64, 5/64, 7/64"
gaps:
1) .018 2) .016
.018 .016
.024/.032 .026/.026
3) .027 .018
.024 .019
.039/.037 .030/.030
5) .022 .021
.020 .023
.035/.037 .033/.032
7) .020 .017
.020 .017
.033/.032 .032/.031
rods:
stock Chevy 5.7" forgings
inboard corners beveled for cam clearance
ARP 134-6003 rod bolts
cam:
Elgin E1029
214/214 @.050, 112LC, .443 lift
installed 4 degrees advanced (offset bushing)
valvetrain:
new hydraulic lifters
1.6:1 intake rockers
1.5:1 exhaust rockers
Cloyes double roller timing set
stock pushrods
crank:
new 383 stroker casting, 3.75" stroke
std main bearings, Clevite MS-909-P; clearance .002-.0025"
std rod bearings, Clevite CB-663-P
rod journals .0005" under; clearance .0015-.002"
new Pioneer 400 harmonic balancer
new Pioneer 400 flexplate
balance:
external balance
new Pioneer 400 harmonic balancer, 8" diameter
new Pioneer 400 flexplate
413 rod big end
413 rod big end
55 rod bearing
55 rod bearing
703 piston with pin
59 rings
179 rod pin end
-----
1877 bob weight
setup RPM 800
balance RPM 650
front imbalance .05 oz-in
rear imbalance .06 oz-in
oiling:
Melling M55HV high volume
6-quart truck pan
misc:
stock iron Quadrajet intake manifold
paint Dupli-Color DE 1640 Plum Purple
stock Chevy valve covers with load spreaders
requires 1/8" hole in thermostat or heater bypass; bypass port in
block is covered by Hard Block.