Thread: TD5 engine - origins?

Originally Posted by Psimpson7

The engine uses ‘through-bolt’ fixings for the cylinder head, which ensures that each cylinder bores is subjected to the same compression from the head. This allows close tolerances to be used for piston rings due to the bore-to-head stablility, reducing emissions and minimising oil consumption. This is helped by diamond micro-finishing of the cylinder bores, a proven Rover method.

What does "through bolt" fixings mean.

Dave.

Originally Posted by Mr Whippy

What does "through bolt" fixings mean.

Dave.

Instead of the head bolting to the block, it has long studs which pass through the block to the bottom of the engine. The bottom has an aluminium ladder frame that houses the bearing carriers, oil pump etc which the head bolts to. This means that the combusion forces are the only forces that act on the block so tighter tolerances can be used as the block remains dimensionally more accurate. The reaction forces from the combustion, compression and reciprocation etc are directed from the head to the crank (or vice versa) through the head bolts rather than through the block.

Thanks Slunnie,
Makes good sense.

Dave.

Originally Posted by Slunnie

Instead of the head bolting to the block, it has long studs which pass through the block to the bottom of the engine. The bottom has an aluminium ladder frame that houses the bearing carriers, oil pump etc which the head bolts to. This means that the combusion forces are the only forces that act on the block so tighter tolerances can be used as the block remains dimensionally more accurate. The reaction forces from the combustion, compression and reciprocation etc are directed from the head to the crank (or vice versa) through the head bolts rather than through the block.

Could this be the reason for the head movement that sometimes occurs and shears the plastic locating dowels? I would have thought that a long stud that goes through to the bottom of the block would be less stiff than a short stud in the head.

Stephen.

Originally Posted by Brian Hjelm

The ECU was developed in conjunction with Lucas!!!!

Does this explain the multiple and ongoing electrical/electronic problems and failures suffered by writers to this forum?

My experience with British cars and trucks has firmly convinced me that the Poms have absolutely no idea when it comes to designing auto electrics and gearboxes.

I have to disagree. Lucas electrics are fine, it's just that they weren't designed to run in an oil-bath.

Originally Posted by Wilbur

I have to disagree. Lucas electrics are fine, it's just that they weren't designed to run in an oil-bath.

The P38A uses, in the main, French electrics - Valeo.

5 letters = code for Lucas.

Originally Posted by p38arover

The P38A uses, in the main, French electrics - Valeo.

5 letters = code for Lucas.

Hmmm.... normally I defend Land Rover products against all criticism and will hear no words against them, but even I have to admit that my 2002 P38a was 'playful' in the electrics. So playful that I had to give up and dispose of the car, which is a pity because otherwise it was a great vehicle.

I am glad to know that the electrics are French. Again I can defend Lucas with a clear conscience - and I am actually being serious, Lucas electrics are very simple and robust. Just have a look at the German made electric seat switches in the 1992 Classic Range Rovers to see how crappy German electrics can be.

In the early 90's I won a large cash bet with owners of BMW, Honda and Kawasaki motorbikes as to the effectiveness of their headlights versus the stock Lucas halogen headlight in my 1972 Norton. Why do we so easily remember the problems that Lucas electrics (like every electrical system) have from time to time, but we forget the excellences? As Shakespeare said, "The evil men do lives on, while the good is oft interred with their bones".

Sorry, I seem to have hijacked this thread a bit! Someone hit my hobby-horse button.

Cheers all,

Paul

Originally Posted by StephenF10

Could this be the reason for the head movement that sometimes occurs and shears the plastic locating dowels? I would have thought that a long stud that goes through to the bottom of the block would be less stiff than a short stud in the head.

Stephen.

Stephen,
I think you will find this is because the dowels are plastic and just not strong enough.

Dave.