221 rods into 250 - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

XA Fairmont · 03-07-2005, 02:48

Gday. Ive got a few questions about putting 221 rods into a 250 x flow.

Why do people put 221 rods into 250's, Is is to make them rev more?
Do they go straight in?
Do you loose many cubic inches?

Thanks Chris

INJECTED250 · 03-07-2005, 03:01

people put 200 rods in the 250's.. its still a 250

yeah right · 03-07-2005, 23:01

They rev harder without throwing rods because the longer rods don't go through such acute angles relative to the crank. The compression ratio goes up but the bore & stroke don't change so the capacity remains the same.

ACL do a range of piston kits for the specific purpose of using 200 rods on a 250 crank, depending on whether you want to turbo it or not.

XA Fairmont · 03-08-2005, 02:55

For a N/A motor do you thing its a good idea? So you cant use 250 pistons?

INJECTED250 · 03-08-2005, 03:18

nope u carnt due to the rod being longer it will make the pistion stick out of the block.. thats why they make pistons with higher pins

clevo400 · 03-08-2005, 06:16

The compression ratio will go up cos the piston will be popping out the deck and hitting the head.
ACL make 2 sets of pistons for the 200 rod onto the 250 crank. One set they say need to have the top of the rod modified so it doesn't hit the innner side of the piston.
Someone had a set of Probe pistons for sale here. Sure he is in Townsville QLD.

XA Fairmont · 03-08-2005, 17:23

Im not intrested in buying any rods yet but are 200 rods easy to come across?

clevo400 · 03-09-2005, 04:27

Any 3.3L crossflow will have em and they r givin em away at the dump but trying to find one is the hard part. I have a set in an engine but don't know what condition they r in yet ???