Two questions I can't find an answer to

[Go Time]

Does any one make a top pinned cast pistons w/ 1.5mm rings for a promax?

Is there an aftermarket source for the Blue NGK resistor plug wires?

[Go Time]

I guess the answers are no & no.... :confused:

[merc326]

Why not run the vertex 1.5 mm ring piston.

[wired247]

No one makes a cast top pinned piston. You can have yours top pinned if you want.

[Go Time]

ODBA, I have one engine with the vertex piston w/ 1.5mm rings and it has worked out just fine so far. But that vertex is a bottom guided piston and requires two large washers when used on top guided rods. I was hoping to find a top pinned cast piston with 1.5mm rings.
No one appears to make a cast top giuded piston with 1.5mm rings period except for mercury, and no one makes an oversized one.
Wired, what did you use in you new Promax block you built?

I did find the NGK plug wires in red from some motorcycle parts places, but you have to cut them to length and put the boots and terminals on the coil end.

[wired247]

ODBA, I have one engine with the vertex piston w/ 1.5mm rings and it has worked out just fine so far. But that vertex is a bottom guided piston and requires two large washers when used on top guided rods. I was hoping to find a top pinned cast piston with 1.5mm rings.
No one appears to make a cast top giuded piston with 1.5mm rings period except for mercury, and no one makes an oversized one.
Wired, what did you use in you new Promax block you built?

I did find the NGK plug wires in red from some motorcycle parts places, but you have to cut them to length and put the boots and terminals on the coil end.


I used the standard 200 HP Vertex pistons with the 2.0 rings and that thing lived at 7200 . Not sure the 2.0 vs 1.5 mm ring thing is worth even searching for. The 225 promax on my Allison has the 2.0 mm ring Pro V pistons in it and it will also live at 7200. Top pinning has its place and if I was running forged pistons past 7K I'd probably have Marles do them . I even considered having my Vertex's done that way just for the hell of it but I tried for weeks to get ahold of John Marles when I was building that one and never could .
I used the Jay Smith's 8mm plug wires just because I loath building plug wires. The ones he sells now are not as "attractive" as the ones he used to sell not that that makes any difference.

[Go Time]

Have you ever heard of WSM pistons? I understand they are built in Germany and come with 1.5 millimeter rings

[wired247]

Ive used WSM pistons before . Not specifically for 225 promax as I dont know those exist. The ones I used were 200 pistons and had 2mm rings.

[eli]

I used the standard 200 HP Vertex pistons with the 2.0 rings and that thing lived at 7200 . Not sure the 2.0 vs 1.5 mm ring thing is worth even searching for. The 225 promax on my Allison has the 2.0 mm ring Pro V pistons in it and it will also live at 7200. Top pinning has its place and if I was running forged pistons past 7K I'd probably have Marles do them . I even considered having my Vertex's done that way just for the hell of it but I tried for weeks to get ahold of John Marles when I was building that one and never could .
I used the Jay Smith's 8mm plug wires just because I loath building plug wires. The ones he sells now are not as "attractive" as the ones he used to sell not that that makes any difference. john marles email works best he will get right back to you