D2 V8 Engine: Slipped Liners and Suitability for Towing

Ultrasonic testing had 4.6 blocks being allocated blocks with the thickest wall thickness between liner and water gallery so maybe you had an unlucky block on the low end of acceptability or it slipped through and is D2 graded block. On account of this grading I would not touch a D2 block for a rebuild.

Having said that, I would still double check a couple of things because surely you used up all your bad luck on that stock and 2nd motor. Was the MAF upsized to a 4.6 version (air signal to match the 4.6 fuel map as loaded)????. and what were your average Scan Gauge coolant temperature readings for unloaded and loaded (towing) running?

T hatting or flange liners are the only way to prevent coolant loss via crack and up around the top of the liner into combustion chamber. Don’t let anyone tell you otherwise like pinning the bottom of the liner will do the trick etc. Apart from block cracking that is causing the slip, your block has a 360 degree “shoulder” already machined in the base of each bore to stop liner slippage. You can see this “shoulder” in the picture in the JE Robison blog above of the block they sawed in half.

I would also use studs and nuts instead of stretch head bolts on account of the correlation between tensioning action and crack locations in relation to bolt holes pointed out in the JR Robison blog, however I am surprised they made no mention of this bolt fix.

The good news is once done you have a better than new donk and that money has gone into the latest RV8 block (with tougher bottom end) all sitting in front of a 24 box. I doubt a D4 would get close to matching this set up for towing.

If you are not doing really hard core offroad, and can stand the more plastic feel of the interior and slow steering one of these would be sweet:

Which will be crowned the Best Tow Vehicle? | Tow Vehicle | Reviews | Caravan & Motorhome

AND - you wont have to be a Toyo driver!

If I wasnt in a D2 I would be in a NS Paj - I had one for a week when the drive flanges on the D2 axles decided to twist. Very nice in the 3.2 Exceed byt the VRX would be a better choice I reckon. On sand the 18 inch wheels would be a restriction for sand use, but the torque would be better. Quite a few of the guys with the 18 inch wheels source 17's to given them more tyre. I think a D2 with 16's and CDL on the sand would be better than the Pajero with 18's but I doubt there would be too much in it in the end and I have seen them driving through Indian Head etc without problems. I have not seen them stop in the middle of a very soft Indian like I did one year waiting for a GU to be snatched out, and then had to start off from stationary and drive through his holes (which it made look easy...) but there you go.

Cheers

Thanks Oz, I agree that the Paj is a very good vehicle. I have experience of two of the current models. But they can't legally tow my van. The Pajero's practical tow limit for caravans is 2.5 tonnes, as once the towed mass exceeds 2.5 tonnes, you are limited to only 180 kg on the tow ball.

Thats true mate, and I know it does not allow you the 10% you might want (and I agree that is a good rule of thumb) but if you had air bags in the Paj rear, a good WDH and anti-sway bars also attached, you could surely get away with less then the 10%? What you reckon?

Cheers

Yes, you can go down to about 7%, but that puts you right on the edge of what is safe. I currently run 250 on my D2 for a 2.7 tonne van, to stay legal and insured, and that is as far as I will go. With the Paj to stay legal, I would have to go to the max permitted at that weight (180 kg) and that would just be dangerous (and potentially uninsured). Otherwise the Paj would be great value for money if not anywhere near as nice to drive as the Disco.

Fair enough mate. Thats a Bummer... I hope you can get a 4.6-5.0 rover well sorted. The other way would be a Gen IV GM conversion but that would be a lot of drama. You could go a TD5 chipped (ie sell the V8 as a going concern and change D2's) but you could never get me used to the sound and lack of smoothness versus the V8 (although a well sorted 4.6 surely would not be outshone towing by a chipped td5?).

Otherwise its larger vehicle time which is a pitty.

Cheers

After lots of help from this forum and from TRS in Adelaide, I have decided to keep the D2. To get a D4 SE with the same capabilities as the D2 (but with almost 50% more torque) was going to cost around $104,000 by the time the long range tank, sat nav, aux battery, UHF, reversing cameras, breakaway brake monitor, electric brake controller etc were fitted, and that is without a front bar. While the D4 SE has a superb engine and drive train, it just seemed to me that it isn't a bush vehicle, while the D2 is. That is not a criticism, just an observation that the design is primarily aimed (quite properly) at the main market, and that is not for caravan towing or remote area use.

We may still go the D4 route later, but for now, TRS is building me an exchange 4.6 short motor with top hat liners which hopefully will be fitted by the end of next week. The HP24 up-grade transmission is still under warranty, and the new engine comes with a substantial warranty (three times the LR factory new engines that failed), so I should be trouble free for a while.

Thanks to all for your help.
Terry

Excellent Terry.

Did TRS have a way of dealing with the potential problem of the thickness of the casting at one or two head bolt holes not being thick enough...it was covered on another site and is said to be the likely problem of many combustion leaks and head gasket failures and on that site the mechs thought it likely to b more likely to be the cause of engine failure than liners and it was the cause of the liner moving in the affected cylinder? If you havent heard of that let me know and I will go searching.

Cheers

Hi Oz,

Yes, they don't use the LR head bolts, but instead use aircraft studs and nuts. That way they get all the threads in the block used, but even if the block did still crack as shown in the robison blog that Pedro gave us the link to, the flanges on the top hat liners would prevent any movement of combustion gas into the cooling system or vice versa. They also use graphite head gaskets instead of LR ones, but whether that is related to the cracking or not I don't know.

I am suffering from Disco withdrawal and am really looking forward to getting it back. Just for interest, the pic is of the rig at lunch just off the road in central Victoria a few weeks ago on one of our trips.

Quote:

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Originally Posted by Grumndriva

Hi Oz,

Yes, they don't use the LR head bolts, but instead use aircraft studs and nuts. That way they get all the threads in the block used, but even if the block did still crack as shown in the robison blog that Pedro gave us the link to, the flanges on the top hat liners would prevent any movement of combustion gas into the cooling system or vice versa. They also use graphite head gaskets instead of LR ones, but whether that is related to the cracking or not I don't know.

I am suffering from Disco withdrawal and am really looking forward to getting it back. Just for interest, the pic is of the rig at lunch just off the road in central Victoria a few weeks ago on one of our trips.

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You are all over it Terry. I thought you would be. It sounds like the ultimate bush and tow vehicle set up.

Nice looking rig mate. Is that Bonnati Grey?

Cheers