PROBE FORGED PISTON SOLID MODELS AND SPECS! LOOK!

Are these pistons acceptable for our group buy?

  • Yes.

    Votes: 36 94.7%

  • No.

    Votes: 2 5.3%
  • Total voters
    38
starscream5000

starscream5000

Senior VIP Member
Aug 23, 2006
6,359
0
36
Hot and Humid, KY
Guys, I'd be more at rest here if wer had a couple figures closer to something like this:

0.250" - 0.260" thickness of the crown under the 20cc dish
0.175" - 0.200" skirt thickness

Ross were made beefy for a reason John. I'd much prefer (and I'm sure others would too) to have these specs closer to the "stoutest" piston for the 7M made. Why are we so worried about the weights here? No matter what, these pistons are going to be a helluva lot lighter than what the stock piston were... I truly feel we are skimping out in this area. I know how you like to build your engine John, overbuild it to exacting tolerances that way you have peace of mind. Please be understanding in this...

I'd also be curious to see the measurements on the other brands of forged pistons for comparison here.
 
D

Doward

Banned
Jan 11, 2006
4,245
0
36
Alachua, FL
I will certainly be passing these concerns along - but as of right now, the very highest hp 7Ms I know of, are running JE (the thinnest and lightest) and Wisecos (another very lightweight piston) - obviously, those two pistons are working VERY well!

The skirt length is a problem I have with the JEs, so well as the ring pack used in the Wisecos and JEs.

So basically what we have here in the Probe piston, is a slightly thicker JE with longer skirts, and a ring pack better suited to life on the street.

Isn't that what we were shooting for in the first place?

As for weight, the Ross is 357g, and the stock cast pieces are 366g. The JEs are 296g, and the Wisecos are 317g.

I think before I contact Shawn again, and we go trying to thicken the piston even more beyond his recommendation, we should really get the specifications on the other piston sets out there.

To my line of thinking, if the Ross' (on the high end of the scale) are .260" thick, and the JE's are more like .200" thick, then the Probes are right in the middle!

I'm loving the discussion guys, keep it up!
 
starscream5000

starscream5000

Senior VIP Member
Aug 23, 2006
6,359
0
36
Hot and Humid, KY
Doward said:
but as of right now, the very highest hp 7Ms I know of, are running JE (the thinnest and lightest) and Wisecos (another very lightweight piston) - obviously, those two pistons are working VERY well!
Click to expand...


We aren't looking to have a race piston here, it's a street piston that will be reliable for plenty of power, last a long time, and be able to take detonation incase a shitty tune, or something going wrong with a good tune.

Doward said:
So basically what we have here in the Probe piston, is a slightly thicker JE with longer skirts, and a ring pack better suited to life on the street.

Isn't that what we were shooting for in the first place?
Click to expand...

Sort of, but with the peace of mind that we won't have to worry about our piston being too thin in certain places like the JE's are. JE's would be right on the edge of tolerance for a reliable race piston, I honestly don't think the majority of us are wanting something like that...
 
bigaaron

bigaaron

Supramania Contributor
Apr 12, 2005
4,692
1
0
50
Pomona, CA
www.driftmotion.com
I have Ross pistons in my own engine, and I really don't like them very much. They are noisy, and it started burning oil in the #6 cylinder at 20k miles. I don't know when Ross became the standard to judge all other pistons by. We built several engines with JE pistons and they worked great.

There is no reason at all to have a .2" thick skirt. I bet the reason that the skirt is .2" thick on the Ross is because they use that same slug in another application with a smaller bore.

I just talked to Doward, and he got some specs on the Weisco and JE pistons:

The Weisco crown is only .160" thick under the dish.
The skirt thickness is only .1" thick.
The skirt length is 2.232"

The JE piston is .230" under the dish.
The length is 2.20" on the skirt.
They didn't know the skirt thickness.
 
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