408-418
Thread Starter
Joined: Oct 2007
Posts: 604
Likes: 1
From: Gainesville FL
408-418 Is there any reason why I shouldn't do 418 ci instead of a 408 . I got a good deal on a crank that would make my motor a 418, or do i pass. I am using a 6.0L castiron truck block. I might FI or nitrous on it,realy haven't decided on that yet WHAT IS YOUR OPINION ON IT ? 
The 418 does have some problems the piston is farther down the bore at BDC and the high pin height in the piston can make them noisey from piston rock if the clearances are not exact. With a good tune and no detonation they will live 4 years or longer trouble free, but on the other hand the top ring is at least .050 closer to the piston top and most piston crowns with a pin height that high are around .040 thinner. If you do the 418 use the wiseco piston set with the steel top ring and you with have less chances of any issues. Do the research there is alot more post on troubles of these engines than the 408's and the 408 is far more common.
I was wondering this myself and from what ive gatherd, if you plan on any type of power adder you really want the top of the piston as thick as you can get in order to take the heat and abuse happening in the cylinder when you add the the power adder. If you were to use that 4.100 crank it would move the rod farther into the pison thus making the piston thinner. Everyone seems to have good luck with the 402 and 408 using the 4.000 crank.
I was looking around on the interweb last night and saw a piston designed to work with a rod that is 6.100 instead of 6.125 giving the piston more crown. Has anyone else seen these or run them?
Also with them could you then be more confident when you go with a 4.1 crank?
Also with them could you then be more confident when you go with a 4.1 crank?
