Originally Posted by
inferno13
i bought and just received a back up 7R off here with a gallon ran through it, motor is in great condition, i took the head off and the guy had 4 copper shims and a aluminum shim in it???? does the 7R shim differnt than the 5R? or can i remove a few copper shims and leave 1 aluminum and 1 copper? running 20% byrons right now.
for now I would leave the .3mm alu shim/.2mm/.1mm then after break in I like to run .4mm or .3mm it all depends on the engine/ pipe temps. If pipe is getting to hot melting bodies=too many head shims. To little shim has reverse effect. It should be on massive mods web site in the tuning area. Mark did a good job a explaining it.
