Engine internal part strength

bigboost7m

New Member
Apr 20, 2005
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Center Line, MI
racetek82;1011846 said:
Okay, Eagle rods it is. Now, any opinions so far on the Probe pistons? The price isn't too far off from just getting JE pistons, so is it worth going cheaper with the Probe pistons? Any money I can save will go toward other deserving mods.


My personal experiences have been anything but good with Probe pistons. I've never built a 7M with probe pisotns, but I have built quite a few "budget" minded builds on V8's with probe pistons. Each one had a really awkward skirt profile; the wear pattern was never the same on any of the pistons. And I know for dam sure the machining was done correctly, it was all done on CNC machines at my old job (Livernois Motorsports). Each set of pistons typically had +/- .0006":aigo: difference between the 8, and they were all measured at the recommended measure point (.400" from the bottom of the skirt). And also, each set of pistons had pin oiler grooves, but they were 180deg apart from each other (9 and 3 o'clock position), the proper place for them would be closer together, near the 11 and 1 o'clock positions, that would intern lead to excessive wear on the pin boss bore.

But then again, none were on a 7m though. I think what usually is true for one is true for all. If it was me, I would go with the JE's, no question about it.
 

Adjuster

Supramania Contributor
The 7M rods are forged, and they are shot peened stock.

The weak link on the stock ones is the cheap ass bolts, and then the oil squirter hole at the shoulder of the rod...

I've seen stock ones fail there, and at the bolts..

HP wise, if your going to spend the money on the motor, why go cheap on the rods?

Pauter makes the nicest 7M rods.. :) This is why I have them on my stroke'd 7M.. Of course, they are really made for a 327 SBC, but hey, the design is the same, only the 327 has 2" mains and slightly larger pin bores than the 7M... (You'll need custom pistons with custom pin heights and much more.)

The Pauters make my engine resistant to abuse, at least so far. ;)