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Re: 240 engine in a 740 (leemillerjr)

Welcome to Swedespeed, Lee.

Any B230F engine from a 240/740/940 will fit.

The main decision will be how to handle the electrics.

If your 740 has all systems OK and just the dead engine then use just the 240 engine and hook it up to the existing sensors on the 740 so that the ECU can adjust to the running conditions of the 240 engine.

That said, be sure the donor engine is OK otherwise you will be wasting much time, labor and $$$.

George Dill
 

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Re: 240 engine in a 740 (gdill2)

Quote, originally posted by gdill2 »
If your 740 has all systems OK and just the dead engine then use just the 240 engine and hook it up to the existing sensors on the 740 so that the ECU can adjust to the running conditions of the 240 engine.

Not quite. Depending on the model year, the MAF, ignition system, ECTs can be different. If so, they'll provide analog signals that the ECU will not understand.

The ECUs in 200-, 700-, and 900-series engines aren't neural net processors. They don't "adjust" to anything, instead going into limp-home mode if they receive unacceptable signals from major sensors. The MAF is one of these sensors. Hall sensors in distributors are others. Ditto for RPM sensors. Engine Coolant Temperature Sensors don't provide information that is critical to the running of the engine, but they'll throw off the injector cycle to the point where the engine won't run correctly.

The bottom line is that the block and heads of B230s are interchangeable, but you'd better swap ancillaries like distributors and sensors.

Otherwise, you'll waste a lot of time learning why...
 
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