Speedman
Active Member
tore my promax down Sat, lost a piston, came apart and scored the cylinder a little, maybe .015. So its off to the shop. jury is still out on what to use for pistons. I have had several reliable people from this board and S&F (including Paul Nichols, Randy, Jay Smith etc) give me their opinions. Some said replace all pistons and if I use Merc, have them top pinned, some said promarine with spacers and others said vertex?? Paul said if I am only turning 6700 that he would use USED pistons top pinned, I don't think I want used so I am still out. I believe everyones experience and am now more confused :? If I understand this right, in order to top pin a piston you have to drill a hole in it, then weld it over? is that correct? how would that effect the piston tolerences, wouldn;t it create a hot spot? not sure on the process, keep in mind,I am no engine guy...small block chevy, I can do! Boat engines, just not learned enough yet...enlighten me!