What’s the recommended piston to head clearance for these “big block” engines?
If it makes a difference we’re running ARC billet rods. I have 0.040” (1.016mm) as the spec now which seems a bit tight for such a big slug.
Background: Going through the VC460 engines on our rental fleet and noticed we have some witness marks on the piston crown. Admittedly the reason we’re taking them apart is due to smoked rod bearing shells… so it could be just that. I figure since were going though them it would be wise to send them out with sufficient head/pistonclearance. Not looking to set to kill.
Here’s the specs I have for reference for our VC460 with billet ARC 4.510” rods. They may or may not not apply to other engines. Open to feedback on these in a non max performance setting.
Big end bearing (ARC 4.510” Rod): Oil clearance 0.002” - 0.004", torque 120 in/lb, 144 in/lb then 180 in/lb
Crank web diameter: 1.4160" +/- .0005"
Ring gaps
Top (Chrome): 0.016”
Middle (Black): 0.018”
Oil scraper rings: 0.015”
Carnage Pics for entertainment.
