Thread: Td5 Bottom End

Originally Posted by Kaaaiju

Hi,

i am rebuilding a new motor up to handle a little bit of power, so any tips for the bottom end with over sized pistons etc or things to look out for?

Thanks

The bottom end is pretty tough, the only thing that ever seems to get them is oil pump failure/oil pump bolt loss.

In fact I've never seen a knackered bottom
End.

Just keep the oil in and the dirt out.

The centrifugal filter is brilliant, every diesel should be using them.

Cheers
James

Have been looking at many things TD5 over the last months and did come upon an older article where they were looking at the development of a more powerful motor and in particular a 2.8 litre version (which I think LRA did one). The overriding point it made was as Shack said, the bottom end is not a problem and capable of higher power than they had possibly thought, this was of course in the early days of the mods and tuning of the TD5.

Even the head has not had too much done to them it would appear and surprised me when I did the head change over as to the size of the valves. Back when it was always the breathing side that engine builders got the greatest gains, oversize valves etc.

One thing that you may be interested in from Darkside Developments (where I got the turbo and manifold from) and that is injectors. How this would impact on the engine will leave it to others to discuss with intelligence but there are alternatives. As they note it would need a proper retune to maintain EGT's

Firad Race Injector Nozzles for Land Rover TD5 Engines (Denso)

Originally Posted by RRT

Have been looking at many things TD5 over the last months and did come upon an older article where they were looking at the development of a more powerful motor and in particular a 2.8 litre version (which I think LRA did one). The overriding point it made was as Shack said, the bottom end is not a problem and capable of higher power than they had possibly thought, this was of course in the early days of the mods and tuning of the TD5.

Even the head has not had too much done to them it would appear and surprised me when I did the head change over as to the size of the valves. Back when it was always the breathing side that engine builders got the greatest gains, oversize valves etc.

One thing that you may be interested in from Darkside Developments (where I got the turbo and manifold from) and that is injectors. How this would impact on the engine will leave it to others to discuss with intelligence but there are alternatives. As they note it would need a proper retune to maintain EGT's

Firad Race Injector Nozzles for Land Rover TD5 Engines (Denso)

I wonder how much the injectors are needed? I hadn't heard of anyone having fuel flow problems, but thats not to say much.

Interestingly TotalTd5 also do a ported AMC head. Its interesting that with petrol engines, people look at the camshaft early on, but nobody seems to touch them with diesels.
Totaltd5 ported AMC head

The AMC ported head will be over $5k delivered and as I already have a AMC head not really worth it

Originally Posted by Slunnie

I wonder how much the injectors are needed? I hadn't heard of anyone having fuel flow problems, but thats not to say much.

Interestingly TotalTd5 also do a ported AMC head. Its interesting that with petrol engines, people look at the camshaft early on, but nobody seems to touch them with diesels.
Totaltd5 ported AMC head

Interestingly it appears they still maintain the same valve size, LR must have got it pretty right out of the box.

As with the injectors, agree, haven't heard of fuel starvation issues at higher psi's (assuming this is where they would come into their own) due to the injectors. The 16P had increased pressure (still below the max the injector was designed for) but seems, same injector cams. On common rail injection, it appears the increases in PSI increases the performance so accepting that the pressure is important (sure the multiple injections etc play here as well), the injector cam itself should be the mod to increase pressure and hence performance... Ahhh know so little but so many questions!

Originally Posted by Slunnie

Its interesting that with petrol engines, people look at the camshaft early on, but nobody seems to touch them with diesels.

The exhaust valve on the TD5 open at 57 degrees BBDC and closes at 14 degrees ATDC. I'm not sure how you could improve on that. Open a bit later maybe to get more power, close a bit sooner to stop exhaust gas re entering the cylinder.
The inlet valve opens at 14 degrees BTDC and closes at 33 degrees after BBDC. I guess at the closing stage the increase of pressure in the cylinder starts to push air out.
I am guessing that most petrol engines are tuned for efficiency, not power. Hence the need to change the cams.

Originally Posted by Bohica

The exhaust valve on the TD5 open at 57 degrees BBDC and closes at 14 degrees ATDC. I'm not sure how you could improve on that. Open a bit later maybe to get more power, close a bit sooner to stop exhaust gas re entering the cylinder.
The inlet valve opens at 14 degrees BTDC and closes at 33 degrees after BBDC. I guess at the closing stage the increase of pressure in the cylinder starts to push air out.
I am guessing that most petrol engines are tuned for efficiency, not power. Hence the need to change the cams.

It is funny when you read these sort of figures and take into account at say 2500rpm, each rev is roughly only 0.024secs and that 1/8 (33'+14') of that is taken up up before opening so giving 0.021 secs to fill the thing up and so, about a 1/5 of a blink of eye to fill up half a litre, even under pressure, how much difference can a few degrees make??? But it must!!

As the post is on the Td5 bottom end, I will share that I have just experienced what appears to be a broken crankshaft.
Returning from a week on Fraser Island, I didn't make it to Gympie.
That was Tuesday, and the Disco will arrive home by tow truck today.
The Gympie Land rover specialist said it is uncommon, and I had never heard of a Td5 breaking a crankshaft before.

Anyway, now to weigh up what to do with the old thing.
I have kept it because anything newer is $$$ for not a lot more capability.
Reliability had been ok but availability of parts is reducing.
But a broken crankshaft?!