Thread: Stirlsilver's Disco Ute Project

Oh your poor neighbours, seeing that thing turn up and sensing the immediate drop in real estate value!

Originally Posted by Davo

Oh your poor neighbours, seeing that thing turn up and sensing the immediate drop in real estate value!

HAHAHA! It does rattle windows at idle...

Land Rover Twin Turbo V8 Ute Project - First Dyno Tune - YouTube

I'll have to explain more later. It's late now and it is still uploading as I post this.

It didn't go bang, it didn't spring a leak and it kept very very cool

Looks and sounds fantastic Stirling. We done !!

Originally Posted by disco2hse

Looks and sounds fantastic Stirling. We done !!

Thanks Alan, don't know about the sound though. You can barely hear it, it's got a pretty quiet exhaust system!

Anyway, this is just a quick update. The final lot of dyno runs were supposed to happen tonight, but it didn't happen. The issue that stopped the tuning of the car was that the turbos were wound up to about 7psi of boost (I had them at 5psi). What we found was that no matter what was done with the injector duty cycles, we couldn't get the fuel into the engine and it constantly would lean out. After a few phone calls, it was indicated that the culprit was possibly the hydrostatic valve that connects the two LPG tanks in the back. Since the valve has a spring inside of it, it can restrict the amount of fuel that flows through the valve. So tomorrow it will be changed to see if we can get enough pressure to the injectors.

Overall the guys at BTA were pretty impressed with the engine, I think it's a bit different to what they normally get in the shop (there is a pulled appart Nissan R35 that they are trying to get 2,000hp out of for example!). In particular, it was mentioned how the engine was keeping so cool despite the power runs, no fluid leaks and very little blow by!

I did identify one other issue while it was on the dyno. The oil pressure was way too low, I changed the oil filter and found it to be completely full of the molly assembly lube which was blocking things up. But despite a brand new oil filter being fitted, I couldn't get more than 200kPa of pressure. According to the specs, the oil pressure should be around 300-350kPa. So, either there is too much restriction in all the oil lines I fitted, or I need to try to push up the oil pressure regulator to deliver more pressure. I'll have to do some experimentation and see. But the take home message is that if you use a molly assembly lube in the engine, change your oil filter ASAP!

Some photos from last week. Hopefully I'll get some more tomorrow evening!






Below you can see on the top blue line how the engine was leaning out towards the end. Also, supposedly due to the car being AWD with a transfer case and the big tyres, the estimate is that the engine is already at approximately 300hp. When I set out to build the engine, I was aiming for 400hp, so I think when the turbos are dialed up to 14psi, that will be achieved.

Apparently you lose 25% of your power with full-time 4WD or AWD. Now, I wonder how cool it's going to be with the bonnet on? These things really trap heat under there. I'm still experimenting with mine. Anyway, nice work and thanks for sharing!

There is so much win in this thread.
I'd like to comment more, but cannot muster a thought smart enough to do justice to the rest of the posts

Hello everyone,
Sorry for the long silence there. Life tends to get in the way. Plus I had a spanner thrown in the works with regards to getting the car sorted out.

The biggest issue which ended up being a show stopper was that when I was looking into the oil pressure issue, I noticed a strange clanging sound coming from the back of the engine when it was idling. After a bit of investigation, I found the source of the problem. The starter ring gear had started to wear into the back of the engine block to the point where it was machining its way in!







After a lot of phone calls talking to Triumph Rover Spares, AB Automatics and a lot of internet searching trying to work out what went wrong. We finally got to the bottom of the problem. I was supplied the Flex Plate assembly of a 4.6L Discovery II when I should have been supplied the assembly of a 4.6L P38 Range Rover. It turns out these assemblies are different, with only the older 4.6L P38 Range Rovers having the large torque converter I used. What I didn't know is there should be a gap between the flex plate and the torque converter when they are assembled. In my case when I assembled the whole thing the flex plate was deformed by a few mm, which has preloaded the crank pushing it forward into the thrust bearing inside.

Below is a comparison of the different flex plate assemblies.

TPD000040 out of a 4.6L Discovery II
TPD000040_USED_1.jpeg

ERR5658/FTC3614 out of a 4.6L P38 Range Rover
192031388376-2_600.jpg

So anyway, the gearbox has to come out and the flex plate assembly changed, which hopefully will happen next week. While the thrust bearing in the engine has definitely had a hard time, I think I will be able to get away with not doing anything to it at this stage.

Alright so the other issue. So the dodgy LPG installer I used ended up taking a whole bunch of short cuts which is what resulted in the fuel starvation problem. They used 6mm gas lines from the tanks to the LPG converter (despite all parts coming with 8mm fittings) and the hydrostatic valve had a whole lot of sealant inside of it causing one side to be completely blocked off.




Hopefully next week all of these issues will be resolved and the car will be back on the dyno to complete the tuning (Things are a bit sluggish at BTA it seems).

Till next time.