That is crazy. Question, I looked back to your first post, why was broken cam shaft your first thought? I would never expected that.

 

The reason I thought that was it was that there was spark and fuel but no fire in the four rear cylinders. All the electronics checked out, but compression failed in the rear 4 cylinders. It was the only reasonable explanation in my mind.

 

Man oh man, I have never heard of a cam shaft breaking, never. Not to say it cant happen, you have proof that it did, but why did it break?
That thing is solid all the way though.

 

That's my next adventure, to figure out why. I suspect that either an oil passage to a bearing was plugged, or a bearing was left out during assembly. Either way, I might just opt for a full engine swap.

 

Man that sucks, I have only heard of BMW (hollow) and Olds diesels breaking like that. My aunt had an Olds that busted the crank at 28K and then the new motor busted the cam at around 84K.

 

You said the motor has about 35k miles? SO was it rebuilt?

 

So here's a question - I know from part of a lifetime owning Hondas - before I got religion, ha :-) - that they use "interference" engines where if the camshaft stops rotating (due to timing belt failure or something like this) the valves basically stop in position, contact the still-moving pistons, and then you are s.c.r.e.w.e.d., for want of a better term.

Is this the same with the v-8's in our Disco's? or are the valves safe if the camshaft stops?

Just curious - still trying to learn more about the beast.

Sorry to hear about the problem and I hope you get back on the road with the least possible amount of pain.

Bob

 

It was supposed to have been a replacement by Land Rover for the previous owner after the original motor failed, so I believe it was a new motor, but I don't know if it was only a block or if the camshaft and heads were included by the factory.

 

That's a good question. I was hoping that somebody could answer that one before I get too far on this project. If I need to have the heads done, I might as well scrap the motor and get another one.

 

That is because your Honda's have over head cams, our trucks do not, they have the standard cam and lifter set up.
When the timing belt on a overhead cam engine breaks the cam stops turning because the timing belt is what turns the cam.
The timing belt runs off a crank shaft pulley, over a cam pulley and then back down, there is a belt tensioner in there too to keep the belt tight.
With this set up they also run the water pump with the timing belt.
Because the cam has the resistance of the valve springs and has less rotational mass than the crank shaft when the belt breaks it stop right now.
But the crank keep on moving, the pistons keep going up and down.
When a piston comes to TBC (top dead center) all valves had better be closed, if not they get bent by the piston if you are lucky, if you are not so lucky the valves punch a hole into the top of the piston.
Not all over head cam engines are this way, some are non interference, meaning that there is enough room inside the combustion chamber for the valves to be open and not make contact with the pistons.

This is not a Rover engine but a push rod "V" engine is a push rod "V" engine, they have not changed since they first went to over head valve.
So this is a cut away of what your engine looks like from the front.
http://www.howstuffworks.com/enlarge...+engine&page=1
The cam is in the middle of the engine, in the "V", or valley.
A timing chain that runs off the crank shaft turns the cam, the lifters are moved by the cam and they move the rocker arms with open the valves.
Timing chains almost never fail and last the life of the engine.