Author Topic: Crank, Rods, & Pistons? (Read 2292 times)

Sinister68 · « **on:** January 16, 2002 - 09:12:15 PM »

I'm putting together a 12 second 440 and was wondering if an Eagle 4340 crank, MP heavy duty rods, & Ross 30 over 10.5 pistons are adequate for this type of setup? �What about Sealed Power moly rings?

Chryco Psycho · « **Reply #1 on:** January 16, 2002 - 11:21:47 PM »

It will be more than adequate, I might do things a little different & use the stock steel crank, Eagle Rods as the stock crank will take approx 750hp. I got 11.7 s out of a stock crank ,6 pack rods, Speed pro forged 6 pack pistons, you can`t have a heavier bottom end but it lived at 7200 rpm for 10 years & never hurt a thing.
The sealed power moly rings are great, the seat fast, get the file fit if you want to be dead accurate, the Total Seal rings are awesome too & will keep it sealed for a very long time

Sinister68 · « **Reply #2 on:** January 19, 2002 - 09:47:49 PM »

I would use the stock steel crank but its already .010" undersize and it's well worn!

In terms of the Ross pistons, what are "spirolox"? Are the larger wrist pins (1.094) better or worse than the smaller wrist pins (0.990)?

Chryco Psycho · « **Reply #3 on:** January 20, 2002 - 12:43:07 AM »

The crank is 10 under and well worn ...SO send me the crank I`ll use it !! Seriously have it machined & use it, if the machining is done properly you will not have a problem with it

The piston pin has to match the diameter of the small end of the rod I believe the .990 is the Chev size & you will have to special order a new set of rods with the .990 dia small end to use that pin size. There are 2 ways of holding the piston pin in place, the factory presses the pins into the connecting rods & the rods squeeze the pins to prevent them from moving, the second way is to put a bushing in the small hole in the connecting rod & machine in a clearance for the pin to "float" in the rod then they use a snap ring in the piston to prevent the pin from moving over too far & scoring the cyl wall. The spirolox are the snap ring used to retain the pin, personally I would NOT recommend using spirolox & just press the pins in for street use, as I have seen too many failures with floating pins & spirolox. The theory is that floating pins free up HP by allowing all 3 surfaces to move [ the 3 surfaces are the L & R pin bosses in the piston & the pin boss in the rod] if this actually frees up any hp is very debatable & I would only use it in all out race engines where maybe 5? hp is criticle

Sinister68 · « **Reply #4 on:** January 21, 2002 - 05:15:58 PM »

In that case, press fit it is!

Author Topic: Crank, Rods, & Pistons? (Read 2292 times)

Sinister68

Crank, Rods, & Pistons?

Chryco Psycho

Re: Crank, Rods, & Pistons?

Sinister68

Re: Crank, Rods, & Pistons?

Chryco Psycho

Re: Crank, Rods, & Pistons?

Sinister68

Re: Crank, Rods, & Pistons?