> SO.. I bought the kit directly from K1, they recently (last year I think)
> partnered with wiseco to put out these kits. It has the 6.2" rods, and shorty
> pistons. Is this a problem for a mostly street, and occasionally strip engine?
As you've probably figured out by now what you have is a Windsor kit
designed for a race block with Cleveland main journals.
> Yes they are dished, with valve reliefs.
Those are pistons for Windsor heads which have the intake and exhaust valves
all in a single line. Cleveland valves are canted. upper ring height...
> Is the stock 351C deck height 9.5 or 9.2?
351C has a 9.2" deck height with 2.75" main diameter.
351W has a 9.5" deck height with 3.00" main diameter.
Race blocks can have either deck height and either main diameter.
> I can start measuring and actually figure out if they will clear or not...
Stroker math is simple :
rod length + crank stroke/2 + piston pin height = deck height (for a zero clear
The pistons are stamped with 5094H3 which, according to Wiseco's website, are
Windsor pistons with a compression height of 1.280".
6.2 + 4/2 + 1.280 = 9.480
As Brent pointed out, in a 9.5" deck height Windsor block, that would be 0.02"
below the deck (assuming an unmilled later block). In a 351C with 9.2" deck
height, the pistons will stick out of the bore more than a quarter inch (0.28").
You'll likely run into the same problem Hans did if you substitute a 6" rod.
The piston skirts will hit the crank. You can try reducing the outside diameter
of the crank but that will upset the balance of the crank which will then need
rebalancing (holes drilled in the throws and dense Mallory (tungsten) slugs
inserted). That can get expensive. A friend had a custom $2100 billet crank
made for his 5.0L-based stroker by a company that does mainly NASCAR cranks.
They didn't realize it was for an 8.2" deck 5.0L rather than their usual 9.2"
and 9.5" deck blocks so the billet OD was too large. The engine builder didn't
discover the problem he had balanced the reciprocating assembly. The crank had
to be sent back to have it's OD reduced and then it had to be rebalanced.
> Is there a problem with having "shorty" pistons?
No but you need pistons with the correct canted valve notches and the correct
compression (pin) height for your stroke, rod length and block deck height.
Plus, on a 351C block, the top ring land needs to be low enough to clear the
notch in the Cleveland block.
> considering the scat kit comes with both for about $2000.
I've not seen a SCAT kit that cam with a flywheel (for a manual transmission)
but I have seen SCAT kits come with flexplates (for automatic transmissions).
> For the record, the only reason I went with K1 was because scat is
> out of stock on the 408 cranks until at least the end of May. (which when I
> started all this, seemed like a long time away. Now, not so long)
Thanks for the heads up. We've got a couple of 4" stroke SCAT kits to order
in the near future.
> i called k1 and they guy is going to "talk to his product manager" and see
> if they will let me return it.
If they claim this is the first time they've run into this problem, you might
want to remind them I warned Tom Molnar in 2008 (I still have his email
messages saved) and Hans Olsson ordered the exact same kit as you (via Wiseco)
and had the same problems back in May 2010.