Can I fit a 4.0 or 4.6 litre engine in place of my 3.5, 3.9 or 4.2?
Yes you can, and we have done this many hundreds of times. Although the later style 4.0 and 4.6 litre engines do not have distributors it is very easy to convert them to take all of your earlier ancillaries.
There are three main differences to the engine block and crank shaft that slight modifications need to be made for. Detailed in our fitting kit instructions, these are:
- The later style engine has a cranks shaft angle sensor located on the rear of the engine block (the opposite side to the starter motor). If the original mounting plate for the sensor was left in place a hole would be left. This plate will require removing and a blanking plate fitting in its position.
- The 4.0 and 4.6 litre crank shaft nose is slightly longer than the early engines. This means that when bolting your original 3.5, 3.9 or 4.2 litre bottom pulley in place it will not pull tight. This is simply taken care of by a spacer (large washer) so that the pulley can tighten to the end of the crank shaft.
- On the rear of the crank shaft there is a small locating dowel, this will stop you from fitting your flywheel to the crank shaft. This can simply be removed as detailed in our fitting kit instructions.
Once these three small points are taken care of you can install an earlier style cam shaft with the ability to drive a distributor and fit you earlier style covers etc.
It is important to consider your ignition and fueling system when upgrading the engine to any specification as these will under more demand.
We would suggest at the very least, for your ignition system, going through our Check List, upgrading to Magnecor plug leads and our Power Amplifier. And for your fueling system using the Weber 500 carburettor, or indeed, if your engine has the later Hotwire fuel injection system chipping the ECU.
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