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300tdi cylinder head onto Discovery 200tdi engine block.

3996 Views 15 Replies 6 Participants Last post by  rdavisinva
My friends Discovery 200tdi cylinder cracked in the usual place between the valves. He couldn't find another cylinder head and as I have parts here we decided to give it a whirl to show others our findings when we put on a 300tdi cylinder head without changing out pistons. We couldn't find anyone else on the internet who had chronicled it to date.

If it all goes horribly wrong we don't's only a 30 yr old engine on a 30 yr old Land Rover.

I'll list what parts are required at the end along with some mentioned as we go along...

200tdi cylinder head

I had a 300tdi head kicking about so as you can see the distance between the valves is further apart than on the 200tdi.

We set about cleaning the dusty head that's been in the workshop with copious amounts of brake cleaner.....

We will need the rocker assembly too.....

We cleaned off the block as best we could in readiness for the head to be fitted, scraping off any left over gasket material........

We put on a new cylinder head gasket and mounted the head.......we torque down first to 40Nm then continue two tightening sequences at sequence at 60 degrees.....each flat on a bolt is about 60 degrees hence the marker pen marks.

300tdi pistons have a different combustion chamber to the 200tdi there should not be a perfect burn pattern going on. We'll see what it drives like later.

300tdi pistons......

200tdi pistons......

You'll need the 300tdi injectors.....glow plugs are the same as are the pushrods.....the 200tdi valve stem caps will work if you haven't lost any down into the pushrod holes.

The first goofy thing you'll find is the hard fuel lines from the injection pump need to be 300tdi....17mm same size to tighten as with the 200tdi, but the thread is different to 200tdi injectors....

You'll also need to take off the connectors that keep the fuel pipes together and parallel. You'll be pulling and bending same to make them fit

Once we set the valve clearances and put on the rocker cover the next goofy thing we found was that the water heater tube was fouling the connection of the water temperature sender which meant the tube would not pass......after tightening the sender gingerly the tube was able to no need for a 300tdi inlet manifold.

You'll also need the 300tdi rocker cover breather canister and the thermostat housing.....after that it's ready to go apart from rummaging about for some water hoses to connect the water pump and heater.

First brief start up just to see that it works......we'll find a water hose routing solution next.....we're thinking it should not be up to full power when we test drive due to the different pistons, injectors but we'll see and report back. We should give it a whirl this weekend.

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Thank you kindly for the updates.

As an aside, the later heads, the sensor shown is water temperature ERR2081. My 1995 earlier head just has a bolt plugging that hole and the 1997 head I have mounted has the sensor as seen.

All the best.


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How did this turn out? How was the power and feel of the engine? Could you have used the 200tdi intake and exhaust manifold instead of the 300tdi intake/exhaust?

The owner reported back that he didn't feel anything different when driving.
Interesting... In the video they have on youtube the 300tdi intake and exhaust is installed. So, did they switch it out later? The intake/exhaust manifold gasket is the same between the two, so it makes sense that the manifolds are interchangeable.
I am wanting to get a hybrid build like this going. So far I have gathered that optimally the pistons should be changed for the 300tdi pistons. The injectors would be 300tdi. The fuel hardlines should be swapped to 300tdi lines. It also sounds like the thermostat housing from a 300tdi is required. The injection pump is exactly the same, no need to switch.
One unanswered question is do you keep the 200tdi connecting rods? My guess is yes. The 300tdi rods are 5mm longer and I have a suspicion that you retain the 200tdi connecting rods.
There is a engine builder in the Eugene Oregon area that is offering these hybrid engines. But, he will not share the information about the parts needed for the hybrid engine build. If anyone else has information please share.

By coindence, I'll be making this head modification to my own 200tdi Discovery engine in my 110 (with my donor 300tdi Discovery for all the parts) over the next couple of weeks except that I will be going with the 300tdi pistons/rings scenario after removing the engine. The alloy 'ladder' at the sump means the big ends can't be replaced from below.

I will keep my 300tdi con rods because the top of the 200 con road is too wide to fit into the 300tdi pistons to make the gudgeon pin line up with the small end. The gudgeon pin is the same part number.

The reason for all of this is that I need to change out my piston rings at present so whilst doing that I can also change out my big end bearings also, which are the same for the 200tdi and 300tdi. A cylinder hone and that should see me ready for this summers travels which, if all goes well, should see a drive to Africa.

All that to one side, a major factor is that 200tdi heads are virtually impossible to find whereas one can purchase new 300tdi heads easily for any future requirements. If traveling I can DHL a head and repair where I stop as it were. It's just a matter of time until the 200tdi head zaps in the usual place.

I'll post up images.

All the best.
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