I have a 60 series cruiser, BJ 60. It had its original 3B engine in it. I purchased a new model 3B engine last week which as per the seller is from a model above 2000. It looked easy but after i started fixing it, i came to know that there is some difference in the chamber or block of the old and the new engines. The brackets of foundations also look different. So i used the old brackets but still it looks out of proportion.
I have few observations/ questions.
1. Is it necessary that the crank shaft is at the same distance from both the frames.
2. The foundations of the gear box (which are with the original fitting) are not in the center of both the frames, they are rather slightly towards the left side. And if the gear is towards the left, than should the crank shaft also be in line with the gear, means it should be towards the left frame.
3. How to know that the engine is not tilted towards any side? Is is right to check the level from the bottom of the chamber plate?
4. What if the gear box is in the original fitting but the engine gets fixed slightly towards one side or it gets fixed tilted towards one side? Would there be any problems?
First question, not really but if running a diesel it helps minimize vibration as most of the rotational forces are absorbed throught the engine mounts and equally distributed to the morth and south frame cross members.
Second question, A horizontal axis positive or negative degree change can cause problems. For instance, excessive u joints wear, excessive shaft vibrations, a pull to the left maybe, and in my opinion if you have the drivetrain and the shaft connected on an angle, the torque transferred through the shaft to the diff will be transferred unproportionately, thus causing more strain on the shaft, and possibly damaging the diff.
Third Question, Vertical tilts are very much normal with most engine fittings, because due to body and chassis structure some don't fit in straight, and there is good reason the tilt reduces vibration, but a horizontal tilt would be the same as the answer for the second question, the best way is to get a balancing tool, one used in construction, a small tiny ruler with a bubble in it, i don't know whats it called but anyways, that could tell you only whats what when the engine is in. If you wan't to check it before the engine goes in, map out your engine, measure each side, measure the mounts, their height, distance between the firewall and the brush guard, and if there is a difference you will see it coming.
Fourth question, a minor change in position is not problem, but a change in horizontal angle would be the same as the answer to second question.
Agree what is said above, just to add a few things.
When engine is coupled with gear box, the centre of crank is centred with gear box top gear/main shaft. And this line should be parallel to a frame rail. It may be nearer to one frame rail then other becuase of fitting and design requirements.