FORD TOUGH

Are all PI heads the same? Is there a difference between the mustang heads and the truck and crown vic heads?

Stevecooper

Valve covers are the only difference. Performance wise they are all the same.

FORD TOUGH

thanks

pcs

01-04 romeo pi heads have a smaller combustion chamber than 99-00 windsor heads, so un-ported the romeo heads will make more power, ported/ re-worked, the same hp.

mustangman281

WRONG

The only difference between any of the PI heads is 03 and 04 they added extra threads to the sparkplug holes.

If anything the 99-01.5 will make more power because they have less of a dish in their pistons. But the chambers are all the same.

pcs

the pi romeo cars will avg more power, part for part than a windsor.
the chambers are different. when i had my windsor heads off and taken to a shop to get cleaned up, they already had a set of romeo heads that were about to get ported.after all the cleaning my winsdor had a 46cc chamber and the romeo heads that 44 cc chamber. both stock heads that had never been off the block.
also 99-01.5 windsor have a 18.5 cc dish on the piston
01.5-04 romeo have a 15.8 cc dish on the piston
http://www.sullivanperformance.com/YVS450/tech/tech.htm

myslow2002gt

The combustion chamber volume was NEVER altered between model years 1999-2004. The difference you saw was the tolerance between two sets of cylinder heads.

Ford PI castings are 43.8cc's with a tolerance of +/- 1.8cc

Stevecooper

Its a cast piece so yea none of them are going to be 100% the same. That being said the mold for the camber is the same on all PI heads no matter where they were made. Ford even lists them as 43.9 /- 1.5 cc combustion chamber, so yea you could see a 2cc difference between heads.

pcs

ford lists the new romeo casting for 43.9 +/- 1/5cc
46cc would still be out of tolerance
43.9cc+1.5cc=45.4cc
46cc-.10cc accuracy of a pyrex titration rig= 45.90cc
close, but out of tolerance for a romeo.
anyways to answer the original question, not all pi heads are the same. they can be swapped for one another, but not they are not identical.