Ross Pistons

I have a complete set of new Ross pistons, the compression height is 1.865, pin is .990. They were ordered for a 4.125 stroker engine.

Can they be installed in a stock stroke 400 or 440 block, if so what rod?

Or do they have to be installed in a stroker engine?


They will fit a .030 over 400 block or .055 over 440 block.

If I mathed right, a stock stroke RB would need a 6.985 Rod and a stock stroke B would need a 6.4675. There is nothing really close.

I used.
Deck Height - (stroke/2) - Compression Height = rod length

First of all this is a bigblock chevy wristpin size so why not use the vast variety of lengths available for it? They do mean either getting a crank with a different crankpin or grinding down a 440 crank. While doing that, the stroke can be adjusted, but it costs money

Stock stroke and stock rod in a 400 will leave the piston down 0.067"

Stock rod and stock stroke in a 440 leaves the piston down 0.217". Using an aftermarket RB rod increases that number by 0.008"
Substitute a 6.86" Hemi rod for the 440 rod leaves you 0.125 in the hole

My choice: Substitute a 392 Hemi rod from Molnar and piston top is 0.035 down, pin bushing is 0.984, should be able to hone to 0.990, and rod journal is 2.375 stock 440 size. Now you only have to buy the rods, assuming you already have a 3.75 crank. The 392 has a narrower big end similar to bigblock chevy and those are in use all over with the larger side clearance.

R.

PS: If you have to buy a crank you'd be foolish not to use an aftermarket rod sized for 2.200/0.990 pins and make the switch There are many more choices to be made going the bigblock chevy route.