The forum software will probably screw up the formating but here goes...

> I have read there are economical ways of doing strokers such as the 377
> by offset grinding the crank. I've read you can use 6" chevy rods,

You have to either narrow the SBC 6" rods or widen the journals on the
Cleveland crank. Narrowing the rods is cheaper and easier if you're offset
grinding the crank but a wider bearing may last longer. If you're going
with an aftermarket cranks, most will use the small block Chevy 2.1" diameter
rod journals and 0.940" width rods. However, the Ford Sportsman and certain
3.85" SCAT and Eagle cranks are set up for 2.311" diameter 351W rods. Don't
get hung up on rod ratio. The effect of rod length is relatively minor.
In talking with Jon Kaase, he mentioned his rule of thumb for rod length is
2" longer than the stroke. He says that has worked well on his engines from
351C's to his mountain motor stuff. All the combos below will have a better
ratio and ring placement than popular 347 cube stroker kits for the 5.0
due to the fact the 351C has a deck height a full inch higher than a 302.

Be aware the aftermarket "Cleveland style" cranks are not exact Cleveland
replacement cranks. Rather, they are cranks meant to go in Ford Motorsport
hybrid blocks (or other race block) which combine the 2.75" Cleveland mains
with a Windsor architecture. The Cleveland snout is longer than the Windsor
one. Most aftermarket "Cleveland style" cranks use the Windsor snout. The
Cleveland snout has a "snout ring" ahead of the #1 main, to space the lower
sprocket out to clear the journal. Windsors have a collar on the back of
the sprocket and are machined flat ahead of the journal. When using a
"Cleveland style" crank in a 351C iron block, a Ford Motorsport spacer (part
number M-19009-A341C, required with 351 SVO crankshaft when used in production
iron 351C engine, will fix the problem. The spacer is not a press-fit and you
can push it on by hand. There are true Cleveland spec aftermarket cranks but
they tend to be custom order. Also, RDI stocks a hybrid 351W/351C timing set
from Dynatech to match the Windsor crank snout in a Cleveland block.

The Cleveland #3 (thrust) main is narrower by approximately 0.009" (as
measured by Jim Sams). Most aftermarket cranks with 2.75" diameter mains
use the narrower Cleveland thrust width which allows the use of Cleveland
main bearings but ask before ordering. The main bearing spacer kit that
allows 351W blocks to use 2.75" diameter cranks uses the 351W thrust width
which requires a special thrust bearing (available from Ford Motorsport).
The cast iron 2.75" diameter main Ford Motorsport Sportsman cranks have the
351W thrust width to match the spacer kit. The 4000 series SCAT "Cleveland
Style" cranks have the Windsor snout but have 2.75" diameter mains and take
351C bearing, including the thrust bearing.

SCAT offers their cranks in versions to use with 6.000, 6.125, and 6.200
inch long rods, the difference being in the OD of the counterweights.
My engine builder wants to external balance to 28.2 oz-in and suggested
ordering the 6.2" version, even though we are using 6.0" rods. That way
he wouldn't need to use any expensive Mallory metal for balancing (could
grind down the counterweights as needed). The tech at SCAT (Brian)
insisted this was a mistake. He said that even with my heavier pistons
(large bore Fontana block) the 6.0" version would likely need to be
lightened. Furthermore, he said the counterweights are cam profiled on
a CNC machine and that turning them down on a lathe would ruin the balance
and not have the desired effect.

> in some cases chevy pistons.

Dave Williams has put together some budget combos that take modified
off-the-shelf pistons:

351C crank, KB112 pistons, Chrysler rods, 3.64 stroke = 373 CID
351C crank, 1.14 pistons, 6.200 Eagle rods, 3.71 stroke = 380 CID
400 crank, 1.14 pistons, Chrysler rods, 3.88 stroke = 398 CID
400 crank, 1.14 pistons, Olds rods, 4.120 stroke = 422 CID

He put together a reciprocating assembly for Jim Sams using a 3.64" stroke
offset ground 351C crank with 6.125" Mopar rods. They could have used
modified Keith Black hypereutectic pistons (1.14" pin height, designed for
a 6" rod 383 cube Chevy stroker) for an inexpensive package. However, Jim
called KB and John Erb (KB's chief engineer) recommended against fly-cutting
the pistons for Cleveland style canted valve notches. Jim ended up with
custom forged pistons. In most cases you're better off with custom forged
pistons. The canted valve Cleveland requires uniquely positioned valve
notches at the edges of the pistons. The limiting factor for Cleveland
stroker pistons is often the valve notch in the block and pistons.
Cleveland blocks are usually notched at the tops of their bores for valve
clearance/shrouding which can place a limit on the top ring placement (needs
to be below the valve notch at TDC plus rod stretch). The depth of the notch
varies from block to block but on my Aussie XE block, it's about 0.27" down
from the deck. If running quench heads on pump gas, you'll probably want a
dished piston for anything over 3.7" stroke. If so, don't use a circular
dish. A d-dish is better and a mirror image of the combustion chamber is
better yet. Wiseco will do a mirror dish if you send them an image. You
need a flat pad on the piston where the quench pad is on the head to maximize
the quench effect.

> It's a little confusing to say the least. Does anyone have any specifics
> for the above combos?

Stroker math is straight-forward:

piston pin height = deck height - (rod length + crank stroke/2)

When I was mulling this all over, I calculated a few numbers. Note this
assumes zero deck on a block that hasn't been milled. You'll have to
adjust for whatever you block mesures out at. Rearranging the equation:

deck height - (rod length + stroke/2) = pin height

9.206 - (5.778 + 3.50/2) = 1.678 r/s = 1.651 stock 351C
9.206 - (6.000 + 3.50/2) = 1.456 r/s = 1.714
9.206 - (6.125 + 3.50/2) = 1.331 r/s = 1.750
9.206 - (6.200 + 3.50/2) = 1.256 r/s = 1.771 what many circle track racers
run with Aussie 2V heads
9.206 - (6.250 + 3.50/2) = 1.206 r/s = 1.786
9.206 - (6.000 + 3.70/2) = 1.356 r/s = 1.622 popular 351C stroker specs, uses
offset ground 351C crank
9.206 - (6.125 + 3.70/2) = 1.231 r/s = 1.655
9.206 - (6.200 + 3.70/2) = 1.156 r/s = 1.676
9.206 - (6.125 + 3.75/2) = 1.206 r/s = 1.633 forged crank, popular high rpm
drag race combo with 4V heads
9.206 - (6.200 + 3.75/2) = 1.131 r/s = 1.653 pushing the pin height limits
for a street motor
9.206 - (5.950 + 3.85/2) = 1.331 r/s = 1.545 Scat cast steel crank, 2.75" Cleveland
mains and Windsor rod journals.
9.206 - (6.000 + 3.90/2) = 1.256 r/s = 1.538
9.206 - (6.000 + 4.00/2) = 1.206 r/s = 1.500 400 nodular iron crank (or aftermarket)

The popular budget choices for a Cleveland are:

1. 377 (3.7" stroke, 0.030" over):
3.7" offset ground Cleveland crank with 6" rod (Olds or 2.1" journal Chevy),
custom pistons. Offset grind 351C crank to SBC journal, widen crank journal
or narrow rods (easiest), 6" rods, custom pistons. Most conservative. Assuming
your crank grinder works reasonably, the least expensive. If not the 3.85"
stroke SCAT or Eagle cranks may be as cheap. Room to go to longer rods (6.125"
or 6.2"), if desired. Conservative compression height and rod ratio with room
for a standard ring pack. Done right, pretty bullet-proof. These are popular
with the Pantera crowd and the Pantera Performance Center in Colorado stocks
pistons for this combo. A friend is running a 377C with C302B heads and a
hydraulic roller cam (Comp Cams 245 deg @ 0.050", 110 LSA, 0.600"+ lift),
830 CFM tuner Holley, 180 degree headers putting down 470 RWHP on 91 octane
in a street-driven Pantera.

2. 393 (3.85" stroke, 0.030" over):
3.85" Scat or Eagle crank with 5.95" Windsor rods or 6" Chevy rods, custom
pistons. Chinese import cast steel/iron cranks with 6" rods and custom
pistons. Also 5140 forged steel and 4340 forged steel cranks are available.
Like a 377 but with more cubes. This is what I picked for my aluminum
Fontana block (3.85" SCAT 4340 forged crank). With the 4.1" bore of my
block I'll be at 407 cubic inches.

3. 408: (4.00" stroke, 0.030" over):
4.00" Ford, SCAT, or Eagle cranks, 6" rods, custom piston, 1.2" compression
height. Most cubes while keeping a decent pin height. Most power for a
given RPM (best torque) but higher piston speed. Any longer stroke and you
risk running into the block notches with the top ring.

Longevity is dictated by the power the engine makes, the strength of the
components, piston speed (a function of RPM and stroke), rod to stroke ratio
(side wall loading) and rin pack (narrow ring packs don't seal as well,
tend to rock at TDC). The 377 is best for high RPM, the 408 the worst.
Keep the 408C below say 6500 RPM and it should live. Premium components will
make any of them live.

The usual Chinese made SCAT or Eagle rods will probably suffice but for a few
more dollars you can get the much nicer 6" Oliver Superlight I-beams. Callies
has a great deal on these. I got my set for $620 IIRC.