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I am researching a possible Cummins engine for old Toyota FJ45 and was wondering if anyone has had any experience with the newer Cummins QSB compared to the older 4BT engines? I am familiar with the Dodge Cummins engines when it comes to the 12 Valve Vs 24 Valve----I would much rather have the 12 Valve. I was just wondering if the older 4BT was still a better engine than the newer QSB? Thanks in advance for any help
 

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4bt/qsb

The QSB is an construction/industrial engine, has full authority
electronics, unless you have some special computer skills, it will be a little difficult to make changes to the QSB...Insite would be required and even with that you are really limited to what you can and can't change.
 

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Can the 4 cylinder QSB be run with a dodge engine computer, or does deleting two cylinders present similarly difficult problems?
If you could essentially turn it into a 4 cylinder dodge performance and tuning options would be greater.
Or am I dreaming?

Grigg
 

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I looked at a few QSB's after seeing this thread, and the 3.3 in 110hp trim is pretty attractive for those of us with smaller vehicles, especially at 585lb dry. Problem is, since its an off-highway engine its probably governed pretty low. I doubt you'll be able to just change a spring and go like you can with the 4bt. Some computer wizardry would probably be required. The 4.5 is available in a good range of ratings, you might not need to do any tuning at all.
Also the ones Ive seen pics of all have SAE bellhousings. It is a QSB, so the 4bt adapters may or may not work. In an older thread about the qsb's somebody said none of the 3.9 junk would interchange, don't know if that includes adapters. Even so, you might be able to source a flywheel and make an adapter ring like the guy at isuzudieselswapper.com did.

http://www.everytime.cummins.com/every/applications/qsb33_const_tier3.jsp

http://www.everytime.cummins.com/every/applications/qsb45_const_tier3.jsp
 

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The QSB series are for off-road, industrial applications.

The ISB is the on-road version.
 

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