6.7 vs 8.3 cummins

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srt cummins

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I just picked up a 2006 sterling acterra with a blown 7.2 c-7 cat engine. Called the cat dealer and the want 11,500 for a rebuilt engine including the core charge. If I'm putting that much into it I would rather put a cummins in this medium duty truck. This trucks have no balls at all but can get the job done. How big of a difference will the 8.3 vs 6.7 in displacement be a factor in towing? I can build the 6.7 to make it a lot better and more efficient and parts are easy to come buy. So the ISC 8.3 or ISB 6.7 to haul with?
 
I want to do the 6.7 I guess it's time to start looking on copart for a decent wrecked truck.
 
8.3l C-series or 8.9l L-series all the way! As the old saying goes, there's no replacement for displacement. If you get an electronic Cummins the instrument cluster in the truck will work off the J1939 data wires just like it did on the Cat. With a Dodge/Cummins engine and electronics the dash will not function.

B-series engines are best in pick-up trucks, not medium duty trucks.
 
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Might wanna be careful with that, your transmission is probably a SAE bellhousing. I don't believe they ever made a SAE housing for a Dodge/front geartrain 5.9/6.7 commonrail engine.
 
If you go with a B-series engine you'll want an RGT genuine Cummins, not a Dodgefvcked cummins.
 
I like the displacement of the 8.3 and the way it's built like a real diesel should with sleeves and what not. I just can't seem to get past they only offer a 360hp tune for the 8.3. I don't want to be drivin down the highway and can't pass the old lady in the right lane.
 
9724VF350 said:
Might wanna be careful with that, your transmission is probably a SAE bellhousing. I don't believe they ever made a SAE housing for a Dodge/front geartrain 5.9/6.7 commonrail engine.
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They did the old medium duty trucks with the 5.9 had them.
 
srt cummins said:
They did the old medium duty trucks with the 5.9 had them.
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Yes, but a front geartrain commonrail ain't a old medium duty 5.9. The bolt patterns on the back of the block are different and possibly the dowel locations are different.


I have a pretty good sized stack of SAE B series housings sitting here.
 
9724VF350 said:
Yes, but a front geartrain commonrail ain't a old medium duty 5.9. The bolt patterns on the back of the block are different and possibly the dowel locations are different.


I have a pretty good sized stack of SAE B series housings sitting here.
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That's something ill have to look into more. What years are the best for electronic 8.3?
 
A 425 HP 8.9L ISL would probably get the job done. I ran one of those (2007 in 365 and 425 HP configs) in a test cell for my graduate research. Love that engine.
 
srt cummins said:
That's something ill have to look into more. What years are the best for electronic 8.3?
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Find a Common Rail 8.3l and I may be able to help you out in the power department. ;)

The HX40 turbo they come with is too small.
 
Not to mention the 8.3 can use a genuine engine brake, not a pansy exhaust brake like the 6.7.
 
I'd go for a the ISL its got a real compression brake, and you find them cheap... or a series 50 they had em 350hp stock in fire application snormally 320hp... stock ,all the series 60 stuff works on them too so you can bump em up pretty good..again real compression brake and beef.
 
I found a 8.3 isc 360 hp 2009 model with 31,000 miles for 6,000 plus shipping. It's a drop in ready to go beside the wiring harness.
 
Sounds decent $ wise, the ISC. Injection pump is not as tuneable as vp44, etc.... The question about the load leash WEEPer brake, relates. That its aWeeper not a compression brake, weepers open at all piston positions, compressions just near tdc. Etc.l
 
Jmpidgeo said:
PacBrake makes a 6.7 engine brake too.
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No, they make an exhaust brake.

Those simply block exhaust flow.
A compression brake (Jake brake, engine brake, intebrake) pushes open the engine's exhaust valve to release compression pressure from the cylinder.

The difference is the exhaust brake is making 65psi MAX exhaust pressure while the compression brake works with over 500psi.

therabbittree said:
Sounds decent $ wise, the ISC. Injection pump is not as tuneable as vp44, etc.
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2009 will most likely be common rail unless its an off-road engine.
 
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