Thread: D2 V8LPG vs TD5

Slunnie - I will defer to your knowledge here, but are you saying that even high k TD5's only need a hone and set of rings (and pistons say) and you back with a motor that will do the same sort of ks again? Otherwise I dont understand why a top end and bottom end re-build are irrelevant to a TD5 - what about crank and bearings for example.

Further, my point about re-builds is particularly valid if you manage to cook one...it can happen.

Cheers

Such a large Blower???

Its a GT20......

That is not a large blower by any stretch of anyones imagination.

Also, the bottom end of a TD5 is a work of art, very large, strong crank journals etc.... Very over engineered for its output.

The V8 on the other hand, is thin wall castings, yes it is a 4 bolt main, but the wall thickness is thin, prone to slipping linings, and the head chamber design shrouds the valves causing poor burn and sooting in the valve region causing missing and poor running.

BTW - Many light truck diesels were small capacity compared to Petrol brethren... Hi BMEP engines are now the norm...

Go to Europe, Germany etc and watch a VW 1.6L diesel blitz you on the Autobarn and you'll understand powerful small high BMEP diesels in action.



ALSO - I personally know of at least 3 TD5s pushing over 280,000km with no issues.

I personally know 6 or 7 V8s which have needed new blocks, liners, heads etc rebuilt / replaced.... in Under 160,000km...

It all comes down to maintenance, driving style, fuel quality, use etc...

Originally Posted by ozscott

Slunnie - I will defer to your knowledge here, but are you saying that even high k TD5's only need a hone and set of rings (and pistons say) and you back with a motor that will do the same sort of ks again? Otherwise I dont understand why a top end and bottom end re-build are irrelevant to a TD5 - what about crank and bearings for example.

Further, my point about re-builds is particularly valid if you manage to cook one...it can happen.

Cheers

Cook an alloy engine of any make and you'll be looking at possible block and head replacement if the metal has changed..

TD5 - Cast Block - Head Alloy (head replacement only)
V8 - Alloy everything - Can require block and head replaced...

Seen both cooked - V8 was replaced (block had gone bad from heat) TD5 had new Head fitted...

And there are now O/Size pistons etc available to rebuild the TD5.

Oooh, triple quote... I don't think I've done that before.

Originally Posted by ozscott

Slunnie - take your point mate however having 16 plus gears might have something to do with the comparo truck motors doing their thing well - and of course the build of those motors is amazing strength wise. The fact remains that no other manufacturer of TDs in larger 4wds use such a small CC with such a big blower...the smallest I can thing of is the 2.8 Patrol motor....which has more than its share of problems and is a towing mole.

I guess its a debate that no one will concede on, but hey they are all landies (I was just correcting some of the earlier posts and adding some balance when I did my (slightly inflammatory) posts.

Just buy a landy!

Cheers

I agree, just buy a landy!

The trucks may have 16 gears, but half of them overlap. The ones that I've driven (Heavy rigids, not semis) have a crawler and then 8 with a split gearbox (Road Ranger) and then there is a small split for the hwy that doesn't make a lot of difference to me. The newer ones have less gears. They have a heap of gears because a large engine like that wont rev very hard, and you're changing into 5th gear at about 40-45km/h already. Newer more flexible motors rev more and have less gears.

I also believe that motor durability is actually more a function of revs used rather than power output

Originally Posted by ozscott

Ohh...Slunnie - aren't you comparing GVM of the Disco with laden weights of the others....ie 50 + tonns for a semi is laden (ie max capacity). So to do the comparo you would need to do the max capacity of the TD5 Disco which is the 2.7 odd for the vehicle plus 3.5 t a trailer...or otherwise you would have to compare the 2.7 odd TD5 with a prime mover sans trailer...at whatever that is say 12tonn or so?

Cheers

Hmmm, good thought though I based the figures on normal operating conditions rather than towing whcih is a bit exceptional. Then again I should have also used a NT 3 or 4 trailer road train as an example also. A D2 with 3500kg in tow has to pull 250kg from the boot due to nose weight so 2500 + 3500 = 6000kg (note that a car licence only allows up to 4500kg) which is the eq of 2400kg per litre which is still well under that of Semi's.

Originally Posted by ozscott

Slunnie - I will defer to your knowledge here, but are you saying that even high k TD5's only need a hone and set of rings (and pistons say) and you back with a motor that will do the same sort of ks again? Otherwise I dont understand why a top end and bottom end re-build are irrelevant to a TD5 - what about crank and bearings for example.

Further, my point about re-builds is particularly valid if you manage to cook one...it can happen.

Cheers

Top end maybe if its got a lot of km's on it, still not the bottom. They're built stronger than petrols. Interestingly, even after being on the market now for 10 years and having asked on here, there is still no evidence of a worn out TD5. Even on my old race motors we would do about 5 top ends to a bottom end, so I'm not sure why the V8 wears bottom ends. If you cook any regular alloy engine you replace the alloy head at a minimum.

I really is a moot discussion though, as really they are both decent motors and it just depends on what he wants from it.

Tombie, I didn't realise it was a GT20 turbo. These things were being used on 2 litre petrol engines by Toyota in the Supra or something. It'd be interesting to see if the GT25 would bolt on. Then again, after seeing Disco Mick put the Nissan 3.0TD turbo on, I'm liking that also!

I'm currently waiting on the arrival of the 1st production ready, bolt on VNT turbocharger for my disco.

Final tuning is being done this week on the unit, so when I get the first unit here (on mine) and upload the tune to it we should see some nice improvements on the vehicle!!!

Note, we are NOT chasing big power, but rather improved numbers with a much fatter torque curve - perfectly suited to the Discovery and Defenders already impressive abilities...

I'll keep you all posted!

Bloody hell...now Im thinking that if I can stick in a set of ear plugs the TD would be better long term (Im a bloke that likes to keep vehicles for a while...hence the 285,000k 95 D1 3.9 V8 auto (all original drive train) and the 140,000 6 year old D2 and wanting to keep the D2 for a LOT longer - love it!).

Bloody men in black...(diesel soot black that is)

Cheers

Although in terms of longevity most V8s put up v-high miles without problems even if you were very unlucky and scored a problem child then a re-build would still see you not out of pocket compared to the purchase price difference between the 8 and the 5...and of course if you wanted to have fun you could go for broke and do the 4.6 - 5 litre with all the bells and have a ball breaker. Just some options here for people who are thinking about the differences between going petrol or diesel.

Cheers

Does anyone on here really actually buy a vehicle based on the cost of rebuilding the engine?

You go to the dealer/Seller, get in it, either you love it or you don't, and it either checks out or it doesn't!

When I was in the market, didn't like TD5, felt like a pathetic little farm truck rattling around waiting for something to happen. I just flat out loved V8. In every respect! Simple. Happy, Personal choice. I don't give a mickey toss about how much a big end whatsamdoodle or a flippetty whidget cost, and I don't care about availablity of outback petrol, I'll improvise. But that's just me! Just have a spare driver's side door lock at the ready. That is so annoying!