The 351 Cleveland Stroker Crank by Dan Jones

Dan Jones discussing Stroker Cranks in the 351
from the Detomaso Email list

(reprinted with permission from Dan)

Q: The part number goes with 2.75 mains, just curious if this is a drop in for the
guys who want a 377? Seems like a good deal, I'd guess you can't get a cast
crank offset ground for much less?

I think Dan Jones said it isn't quite a drop in, but maybe just takes knowing
what you need to do?

Same seller has a 4 inch stroke crank for you guys looking for big torque.
That might be a cheap big torque motor build because the 4V heads should be
happy with the big stroke?

Dan: Those types of cranks are often referred to as "Cleveland style" because
they use the 351C main diameter. 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. Cleveland cranks have 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.

Most aftermarket cranks use small block Chevy 2.1" diameter rod journals
and 0.940" width rods. However, Ford Sportsman and certain 3.85" SCAT and
Eagle cranks are set up for 2.311" diameter 351W rods.

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.

Canted valve Cleveland heads require 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.

Dan Jones