cracked piston

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
7,535
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34
Lexington, Ky
I've got my sleeves and head cut for an oring. Some people say it's not a good idea to ring a duramax because of how close the coolant ports are to the cylinder though


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bml2200

Member
Oct 16, 2008
256
0
16
IL
If your're already going to be machining for o-rings, why not drill out everything to fit Socal 14mm studs instead of the 625's?
 

MarkBroviak

DMax Junkie
Vendor/Sponsor
May 25, 2008
2,134
464
83
Danville Indiana
If your're already going to be machining for o-rings, why not drill out everything to fit Socal 14mm studs instead of the 625's?

That brings on a whole other list of issues that don't seem to be worth the trouble to me. Having to sleeve the bolt holes in the head because the broke out isn't my idea of a good time. Dealt with two motors with the 14mm studs and don't plan on it again anytime soon. The 625's have been more than effective for us so far. I'm a little more unorthodox than most I guess, so take it for what it is worth. We still run cast oval pistons in Brett's truck that goes 8.5xx@161mph in the quarter and yet guys are having issues with cracking Mahle race cast factory bowl pistons at 700-900hp range. Call me crazy but I'm going to continue doing what is working great for me.:D
 

bml2200

Member
Oct 16, 2008
256
0
16
IL
That brings on a whole other list of issues that don't seem to be worth the trouble to me. Having to sleeve the bolt holes in the head because the broke out isn't my idea of a good time. Dealt with two motors with the 14mm studs and don't plan on it again anytime soon. The 625's have been more than effective for us so far. I'm a little more unorthodox than most I guess, so take it for what it is worth. We still run cast oval pistons in Brett's truck that goes 8.5xx@161mph in the quarter and yet guys are having issues with cracking Mahle race cast factory bowl pistons at 700-900hp range. Call me crazy but I'm going to continue doing what is working great for me.:D

Thanks for explaining. I've also cracked delipped cast mahle pistons in my old LMM, sucks.
 

meshanic

All In Trucks
Dec 9, 2010
436
0
16
West Texas
Really good tech here guys! Speaking of building the bottom the best way possible, how do you guys feel about billet main caps compared to dowel pins in the stock caps? I'm having my billet main caps dowel pinned because I already had the billet main caps line bored when I started hearing about the dowel pins.
 

RPM Motorsports

smokinum
May 13, 2008
3,271
10
38
Central Valley Ca.
Just food for thought, we ran stock de lipped LB7 pistons well over 100 passes at 1k hp in the Chevelle. We never cracked one until we started adding the N20 to it. I'm thinking they survived the conditions because of the 3560lb weight, but who knows. We never expected that motor to live as long as it did. Basically bone stock motor with Carrillos and std ARP 2000's @ 90+ psi boost.