What's the reason for wanting a 4 cylinder over a 6 cylinder? 6 cylinder has more torque, more horsepower, sounds beautiful, mine averages 17 mpg which isn't that far off of a 4 cylinder petrol (infact I have a friend with a 4 cylinder petrol who gets less than that), I will admit that if your engine needs rebuild then it would be expensive but if it's working why go to all the effort changing engines, moving mounts, potentially moving the gearbox and sourcing new props?
FlyingPete
Well-Known Member
That's the way to go I think. At least make the conversion reversible without too much effort, and keep all the bits somewhere! When/if you come to sell it, you could then put the 6-cylinder back in, and use the 300tdi somewhere else. May be a good opportunity to rebuild the 6-cylinder engine if it's getting a bit tired.
CarlosVanDango
Active Member
i dont mean i want a 4 cylinder i mean i'd swap the 6 cyl for a 4 cyl vehicle and then convert that to a 300TDi - the 6 cyl doesnt need a rebuild its low mileage and runs sweet - i just dont want an uneconomical petrol engine
CarlosVanDango
Active Member
unfortunately i can keep the 6 cyl engine as i dont have space but on the plus side i have no intention of selling the 109 once its done how i want it
waldamar
Well-Known Member
Well I hope you're right...................... truth is any special, custom or conversion never gets back the money invested in it, so when you've converted this 6 pot to your specification, assuming you do it REALLY well it'll be worth 4 or 5 grand tops. Meanwhile Christies or Bonhams will be selling original 6 cylinder Safaris for 10 grand plus! Can't you find an ex MOD 109" for your project?
jamesmartin
Well-Known Member
neither does a restoration,its got to be down to what an owner wants
waldamar
Well-Known Member
True, but as we know, unrestored ORIGINALS make good money - all I'm saying is possibly leave this rare 6 cylinder alone........................... [please]
jamesmartin
Well-Known Member
perhaps ,but done well the vehicle is still there ,and used as it should be ,theres enough in museums
waldamar
Well-Known Member
Good point well made, BUT......................... My point is that there are plenty of far more common vehicles available for this kind of project - yes plenty in museums but more kept on the road would be good............
samc88
Drivels spiritual representative
If i had a 6 cyl that was good condition id be looking at an lpg conversion. With the cheaper fuel you'll be looking at an equivalent of around 30mpg or roughly the same as a tdi, which are also hideously loud. The main reason i didnt swap my 2.5na out for 300tdi in my series
FlyingPete
Well-Known Member
LPG is a viable option for the big petrols. TDis are pretty loud, clattery beasts compared to the petrol engines. More vibration from a 4-cylinder too. Fine in a Disco with lots of sound proofing but in the tin box that is a series I think the noise would be objectionable. Smoother, quieter running and about the same cost to run- what's not to like?
discodazza
New Member
Hi all im just about to do the same conversion 6cly to costly to run and maintain and cost fortune to get hardened valve seats fitted and i want to use it as my daily drive it has no overdrive 45 mph flat out So im about to fit 300 engine r380 box and lt77 transfer box all from rusted out disco. I was going to fit the 300 to the series box i intended to get the 6 cyl flywheel housing redrilled to suit the 300 engine but cost of overdrive to get better top speed was going to cost way to much please keep us posted on your project
jamesmartin
Well-Known Member
3.54 diffs is a better option
FlyingPete
Well-Known Member
Agreed. Should definitely be capable of more than 45mph. Even the diesel will get there eventually.
Yup, I've taken mine with no OD up to 63mph on the motorway once (only once) but it's happiest cruising A roads at 50mph (read that as me having some mechanical sympathy for the box and engine!).
FlyingPete
Well-Known Member
Seems like an engine that was calling out for a factory-fitted 5-speed box. What would be good is an overdrive, geared so that 3rd+OD gives a 5th gear, with 4th+OD as a long 6th gear for cruising unladen.
CarlosVanDango
Active Member
i've got a 4 cyl bellhousing now so i'm going to try fit it up to my 300tdi 1st then pull out the engine
i'll keep the build thread updated on how i get on
i'll keep the build thread updated on how i get on
CarlosVanDango
Active Member
i havent got a 300Tdi starter motor - i take it thats the one i would need?
cheers
cheers
