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SCAT crank

6.5L

6.5L

Old Iron Runner
Messages
1,177
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433
Location
Northwest Wyoming
Question 1: Is the Optimizer 6500 series crank better or different than stock GM crank???

Question 2: What makes a SCAT crank better than a stock or Optimizer crank???
 
The specs I got last November (from Peninsular) showed two cranks for the 6500 where the only real difference was one had a 'beefier' crank than the other and the commentary from Peninsular was that most folks went with the beefier one. And IIRC, in stepping up to the P-400 (again from Peninsular) it used the beefier crank.

From what I can tell, visually it does not look like much, if any difference from the beefier Peninsular 6500 crank and the SCAT, but am not in a mood to get spanked by better experts if in fact there are any important differences :hihi:
 
The p400 uses a forged crank the scat is cast but with better quality materials. I've never read anything on the optimizer cranks.

Sent from my Studio 5.0s using Tapatalk
 
The GEP crank is done by Navistar from what I've read, its cast and better than the OE crank. Scat seems to be hit or miss from what my machine shop friends say so if you can find a GEP crank, I'd prefer that over Scat.
 
I've also heard SCAT cranks were hit and miss. I got the GEP Optimizer crank. I was gonna see if I could just stick with the GEP crank that's in my Optimizer now. Which is kind of a relief. I guess now that money can go towards the Moose pump. Hello 120cc's of awesome. Got a big plan in the making
 
6.5L said:
I got the GEP Optimizer crank.
Click to expand...

Two ways to interpret: the regular crank in the 6500 or or the forged crank from the '400 HD' / P-400 . . .?

Went back through my notes, and the 'beefier' crank that I mentioned earlier was forged which was an option in the Optimizer ('400 HD'), so the P-400 has the forged it as well.
 
I too have heard scat cranks can be hit or miss in the 6.5. Surprising because there stuff on the gas motor side is damn near bullet proof. Weird that they have not been able to back that rep up with there 6.5 cranks.
 
Chevypoor said:
I too have heard scat cranks can be hit or miss in the 6.5. Surprising because there stuff on the gas motor side is damn near bullet proof. Weird that they have not been able to back that rep up with there 6.5 cranks.
Click to expand...

I was meaning more towards their line. My machinist has checked a few Scat items brought in and they weren't true or round etc.
 
6.5L said:
Not P400
Click to expand...

Ok, but the 6500 crank could go either way (or more specifically when I ordered last November) as the forged crank was an option and not an automatic part of the build. Put another way, it was possible to get the less beefy crank in the 6500, or pay to upgrade for the forged crank.
 
Seeing as it was a teds motor, I kind of doubt it has the forge crank. However, even if the "less beefy" crank isn't forged, as long as its better than stock GM crank, I don't care what it is.
 
JayTheCPA said:
Ok, but the 6500 crank could go either way (or more specifically when I ordered last November) as the forged crank was an option and not an automatic part of the build. Put another way, it was possible to get the less beefy crank in the 6500, or pay to upgrade for the forged crank.
Click to expand...

I would venture to say the GEP stock crank is miles better than any 6.5 crank, so even though its not forged, I wouldn't hesitate to run one.

6.5L said:
Seeing as it was a teds motor, I kind of doubt it has the forge crank. However, even if the "less beefy" crank isn't forged, as long as its better than stock GM crank, I don't care what it is.
Click to expand...

Yep, its better.
 
I wish I took more pictures when I had mine out of the optimizer and the van engine to compare. I remember seeing differences, but can't remember details, sorry. The rods, and cam were also made different. You guys will get me trained yet.
 
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