Jump to content

Converting to V8

Recommended Posts

Chaps, I'm seriously considering converting my 300tdi 90 to a Rover V8 and am interested to hear the thoughts of anybody who has done this already.

I realise the engine mounts will change and a bigger rad is required. But does anyone have experience of modifying the wiring loom and doing the plumbing of air,water etc pipes?

Anything to look out for?

Link to comment
Share on other sites

I briefly owned a converted 100 from 2.5TD to V8 LPG. This did have an auto box attached to it, so it may bring it's own issues!

The main diferences I observed (but bear in mind I didn't do the conversion) was:

New power steering hoses

New rear prop shaft (engine was sited so that front prop remained original)

New engine mounts

New transnmission cooler

Significant wiring changes (but this was an LPG conversion as well!)

Mods to exhaust

Hope that helps



Link to comment
Share on other sites

I am in the process of doing exactly the opposite. V8 on LPG with 4 speed auto to 300tdi manual. I have just put an offer in on a full engine through to transfer box with the radiator group.

So out of mine will be coming a complete plumbed 3.5 EFi on carbs with a ZF auto along with a one year old radiator. Got all the EFi valley as well bar the mass meter, also the full wiring loom, ECU and exhaust system. The simple LPG systems are easy to wire you don't need all the sensors as the brain can work things out as long as you have the Lambda sensor in the downpipe.

I love the V8 / auto setup, makes driving in town so easy. The main reason for the change is the range and availability of LPG. We want to go to the far reaches of Scotland and I don't want to be continually searching for LPG. Yeah you can plan around LPG stations at 50 miles apart, but there is no guarantee that they still sell the product and we like to take a diversion on a whim.

Hope this helps

Link to comment
Share on other sites

There's a mass of info on here about V8 conversions, but I'll just mention a few things that spring to mind.

Wiring wise, no real problems.

The diesel pre-heat function of the ign switch will become redundant.

The V8 engine loom can be coupled to your existing main harness, may need to solder wires to adapt the plug, but stuff like water temp wires, starter solenoid can all be joined to what is alrady there.

Do don't say if your V8 is carb or efi. If efi you'll need to provide power to the ECU, no real problem, just another ign switched wire. The ECU plugs into the engine look IIRC.

Water pipes - well just buy ones intended for a V8 Defender.

Same can be said for the radiator, although many use a 2.5 turbo D rad, as it has the oil cooler circuit built in. If your engine has no oil cooler circuit then this doesn't apply.

Best to keep your gearboxes in the std position, you can keep your existing props that way, and that will determine the engine position. You will need to make sure you have a suitable gearbox with your engine. The tdi one will have a different bell housing and input shaft.

Not that tricky a job once you have the right bits. Keep in mind there are already std parts for a V8 Defender that will make life easier if you use them.

Hope this helps a little.

Link to comment
Share on other sites

I did exactly this conversion. I kept my R380, just had the mainshaft changed for a V8 one and bought a v8 bellhousing and clutch etc. I initially put a 3.9 in - now i have a 4.6. From what i have learned, Don't waste your time and money on converting to a 3.9. It uses way too much fuel for the power output compared to a 300 tdi (it actually produces less torque where it matters than a 300). If your gonna do it put a 4.6 in, it uses just as much fuel BUT the smile factor is huge!

Just my ten pence worth others will disagree.


Link to comment
Share on other sites

You can just about get away with keeping your existing tranny, and fitting it with a 300series disco V8 bellhousing.

The 300tdi/v8 input shafts are the same length, the only real difference being the pilot bearing on the v8 is smaller, so this will need bored out to accept the TDi shaft.

Seriously dont bother with a carb engine. EFI is a must, and megasquirt will improve things further.

I'd also try and get a later serpentine engine with the better crank driven oil pump, as they tend to be in much better condition due to the improved oiling.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy