I sent an email, and a reference to the pictures and this thread. Really really strange. Frustrating too! =)

 

So, any reply from Diamond??

 

No sir, and I'm getting kinda pissed off. I'm gonna have to call them tomorrow hopefully!

 

Keep us posted...

 

Diamond pistons are not going to be that far off. You need to be sure these extras weren't ordered with a little extra size for some honing cleanup etc. since they may have been ordered that way by the engine builder. Also whoever did the machining should have asked you what you were doing with this stuff and what kind of recomended clearance should be run. With a bigger blower Diamond themselves will probably recomend a little extra clearance depending on the power you are intending to make. Did you order these yourself direct from Diamond or was it through Victory? If it was through Diamond they will fix you up otherwise you need to talk with this Victory place.

 

Yeah it looks like you have an newer updated piston from what you started with. Same part number but different design now. The other pistons might have been a much older set? I haven't seen many like that in a long time.

 

Thats a real pain for them to make changes and keep the same part number. We have 3 different pistons with the same part number...

 

Yep! I deal with stuff like that everyday and people don't ever believe me!

 

Hey there guys, I just got off the phone with Eric @ Victory, its seems you have received two updated redsigned style 11503s. This is where you are seeing a differents in looks. We continue to update and make our product better for our customers, however if we made a new part# for these everytime we made a update we would have a million part numbers.

Now on to your problem, I spoke with eric, and I would really like to get both the new pistons we just sent you and a old piston that you our currently using. Something doesnt sound right, your block should be finish honed to 3.905 for the use of these pistons. The actually piston size should mic @ 3.9015 giving you a .0035 piston to wall clearance. Once I rec your pistons back I will measure them myself and see where the error is. If you have any questions please feel from to give me a call @ the shop, 586-792-6620.

Thank You For Your Time.

 

Cool, mine all measured 3.9015 when I measured them in the correct place...

 

If I'm not mistaken... Shouldn't the clearance on a 15+psi boosted motor be over .005"?

 

Probably but he was just saying what it should be if you only honed it right to 3.905. If you wanted to hone in another .001 clearance and go to 3.906 I know Diamond Mike probably wouldn't mind at all on a more serious blown app.

 

With our skirt profiles, you do not need to run them that lose. If this is a street driven engine, .0035-.004 piston to wall will be perfect. If you give it too much piston to wall clearance you will have excessive piston noise on fireup.

 

Cool Mike, I'll be shipping the 3 pistons out today fed ex express. I'll send you a pm right now.

 

I was going to shoot for .004 clearence. I figure at 14psi I will be at 760rwhp. With the added cooling of the Meth to keep combustion temps down I think it should be fine.

What do you think...??Or should I stick with .0035???

 

Mike responded to me and said .004" would work like a champ, so that's exactly what I'm going to do. =)

 

.004 Piston to Wall will be perfect for your application.