Thread: 300tdi 2.8lt conversion kit

I looked into it when rebuilding recently.
I was needing to put in OS pistons and get the crank ground so it would have been minimal increase in machining costs to set the block up for the 2.8 and the new 2.8 crank would save on machining the old one...

However the experienced and well regarded engine machining shop I used poked and prodded the block I was getting worked. In his opinion taking the bores out the requisite 100thou (I think this is right for the 2.8) was borderline.
You would only need a small defect in the block casting to turn your donk into an expensive and somewhat heavy paper weight.

I spoke with M&D about this who said they have done "6 trillion over bores and never had a problem" call me gun shy - I didnt want ot be the first!!!
I went with 40 thou pistons and am happy with the outcome.
Only 250 hours on the rebuild but it is the nicest 300 that I have experienced.

Steve

Cost wise it looks good but i'd also worry about boring the block out that far, i thought they might supply new liners.
Is the 2.8 a larger stoke and bore ?

Yeah larger stroke and bore.
No liners just over bore the cast block, new crank and pistons. I think new rods but cant be sure on that one.

If it was supplied with liners - obviously the block would then have to be bored even further again! You might end up with a wet linered engine

S

Originally Posted by roverrescue

Yeah larger stroke and bore.
No liners just over bore the cast block, new crank and pistons. I think new rods but cant be sure on that one.

If it was supplied with liners - obviously the block would then have to be bored even further again! You might end up with a wet linered engine

S

Yes.

Based around many of the International HS2.8 internal parts, this kit increases the cubic
capacity of the ‘300’Tdi from 2.5 litres to 2.8 litres.
The kit comprises of :-
1. New crankshaft.
2. Set of new connecting rods.
3. Set of new pistons and rings.
4. Set of new big end bearings.
5. Set of new main bearings.
6. Set of new thrust washers.
7. Special metal layer head gasket.
8. Full instructions and dimensions for rebore of block.

I too wouldn't trust it.

You only need the slightest of core shift and your block is cactus, and Land Rover castings sometimes don't have the greatest of reputations.

Ad to that, how stable is a thin walled bore ?

You want the bores to be nice, straight and as parallel and true as possible during combustion to retain ring seal, when thinning the bore that much... Hmm...


Put it this way, the real 2.8 block must use wider cores, although using the same bore spacing.


Personally I'd rather get a 2nd hand 2.8 engine out of a wrecked Ford Ranger in Brazil or Argentina and do it up rather than risking all that machine work on a thin walled 300Tdi block.

What would be the engine size if you stuck with the original pistons and just used the 2.8 crank? Would this increase the torque of the engine by a large or medium amount or not enough to bother with?

The issue is
The kit consists of crank/rods and pistons
You would first need to ensure that the 2.8 rods would work with more standard pistons

Assuming that my memory is correct and the over bore is 100 thou overall bore diameter is increased by 2.54mm. I think stock is 89mm, So roughly roughly roughly the overbore should account for 5.5% of the capacity increase. So then that the stroke (cran kand rods) accounts for the remainder amount.

Soooooo if you could attach OEM style pistons to the 2.8 rods you WOULD still get an appreciable increase in engine capacity

S

Originally Posted by luke68

What would be the engine size if you stuck with the original pistons and just used the 2.8 crank? Would this increase the torque of the engine by a large or medium amount or not enough to bother with?

The torque increase is almost entirely from the vnt turbo pushing more boost . The extra 300cc is a minor player.