New chassis... thinking of doing a 2.8i conversion

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R0B

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38
Been a while since my last post here, my chassis has been condemned by the MOT man so not used my 110 for nearly a year now while ive been saving for a new chassis. Anyhow, ive seen the South African BMW engine'd defenders and its got me wanting to change the engine at the same time!

My question is has anyone done this conversion themselves before and what was involved? Also, does anyone know which chassis the 2.8i defenders were based on? id guess 300 tdi looking at the time period they were made?
 
You may find like all n/a petrol engines the need to rev it to get anywhere can be bloody annoying, but once its on cam I bet it will shift and then some.
I would also guess its fuel consumption might be 20 on a run on a good day, town work in winter might be down to single figures?
 
Following on from the above, if the torque is quite high up the rev range it would make it a useless tow vehicle to, just something to think about
 
im not concerned towing ability or mpg, my defender is more of a weekend toy and does about 3000 miles per year. More interested to know about things like engine mounts and whats needed to fit.
 
Following on from the above, if the torque is quite high up the rev range it would make it a useless tow vehicle to, just something to think about
You really need to study some dyno plots. Just because an engine might make peak torque higher up the rev range, does not mean they don't make torque at low rpm too.
 
The 2.8i are basically a 300tdi a firm called motor and diesel engineering do the engines and kits to upgrade an exsisting 300tdi but there not cheap there was a kit on eBay for the crank and pistons and other bits for the block for £1795 plus I think you need other stuff as well . Have got a link on my computer to a thread were someone has done the 2.8i conversion can put a link up for you if you want tomorrow as I'm on the iPad now .
Cheers Ian
 
You really need to study some dyno plots. Just because an engine might make peak torque higher up the rev range, does not mean they don't make torque at low rpm too.

Yes im aware of this. But if the peak torque output is at something like 4000 rpm or higher ( I assume as a Beemer is a fast-ish going road car) then it seems unlikely that a normally aspirated (2.8 petrol) would have the kind of torque you'd want for a serious load lugging Landy, where you want peak torque as low as possible.

I think that the td5 in standard form is not as 'driveable' in regards to towing as a well running 3.5 v8, because the v8 has great torque lower down. Iv driven both and this is certainly my feelings, especially in regards to towing.

I'm not saying because the peak torque is high up in the rpm's that it has NOTHING down low, just unlikely to have enough from a small petrol for what id want.
 
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im not concerned towing ability or mpg, my defender is more of a weekend toy and does about 3000 miles per year. More interested to know about things like engine mounts and whats needed to fit.

Richards Chassis' have a great reputation for building chassis' to customer specifications, and they are great at communication to which helps massively!

Id give them a ring first and see if they have done a chassis with this exact engine mod, it may be a slim chance but if they have it should be easy, if not I guess you'll need to research the south African defenders and see I there are any clues as to how/what they do.....all this info can be passed on to Richards. Good luck with it mate, I love modified landys, especially engine conversions! :)
 
The 2.8i are basically a 300tdi a firm called motor and diesel engineering do the engines and kits to upgrade an exsisting 300tdi but there not cheap there was a kit on eBay for the crank and pistons and other bits for the block for £1795 plus I think you need other stuff as well . Have got a link on my computer to a thread were someone has done the 2.8i conversion can put a link up for you if you want tomorrow as I'm on the iPad now .
Cheers Ian
I know what you are talking about but he is talking about the 2.8 BMW lump that was in SA Defenders.
 
Yes im aware of this. But if the peak torque output is at something like 4000 rpm or higher ( I assume as a Beemer is a fast-ish going road car) then it seems unlikely that a normally aspirated (2.8 petrol) would have the kind of torque you'd want for a serious load lugging Landy, where you want peak torque as low as possible.

I think that the td5 in standard form is not as 'driveable' in regards to towing as a well running 3.5 v8, because the v8 has great torque lower down. Iv driven both and this is certainly my feelings, especially in regards to towing.

I'm not saying because the peak torque is high up in the rpm's that it has NOTHING down low, just unlikely to have enough from a small petrol for what id want.
I can't comment on your preferences, however I suspect like most modern'ish engines, the 2.8 BMW unit probably makes pretty good torque at lowish rpm.

For reference, a low CR 3.5 carb Rover V8 makes approx 185ft-lb of torque, PEAK at 2500rpm.

The BMW 2.8 makes 203ft-lb of torque, PEAK at 3950rpm.

However the BMW is a multivalve engine, so more than likely makes at least 80%+ of its Peak torque from under 2000rpm. This means, in reality a 2.8 BMW unit probably matches a low CR 3.5 RV8 for torque below 2000rpm.

The 4v per cylinder BMW unit will likely feel more racey, because it'll carry the torque further up the rev range, which is the reason it makes more power.

The BMW engine can also be tuned to make approx 225hp, up from the stock 193hp, by simply swapping on the intake manifold from the 2.5 litre version. For some reason BMW 'restricted' the 2.8's power output (likely due to insurance reasons in Germany at the time). This change would also improve torque across the entire rev range.


An EFI 3.5 or a 3.9 RV8 should make more torque below 2500rpm than the BMW 2.8. But the BMW engine is likely more than sufficient for most towing needs.
 
I can't comment on your preferences, however I suspect like most modern'ish engines, the 2.8 BMW unit probably makes pretty good torque at lowish rpm.

For reference, a low CR 3.5 carb Rover V8 makes approx 185ft-lb of torque, PEAK at 2500rpm.

The BMW 2.8 makes 203ft-lb of torque, PEAK at 3950rpm.

However the BMW is a multivalve engine, so more than likely makes at least 80%+ of its Peak torque from under 2000rpm. This means, in reality a 2.8 BMW unit probably matches a low CR 3.5 RV8 for torque below 2000rpm.

The 4v per cylinder BMW unit will likely feel more racey, because it'll carry the torque further up the rev range, which is the reason it makes more power.

The BMW engine can also be tuned to make approx 225hp, up from the stock 193hp, by simply swapping on the intake manifold from the 2.5 litre version. For some reason BMW 'restricted' the 2.8's power output (likely due to insurance reasons in Germany at the time). This change would also improve torque across the entire rev range.


An EFI 3.5 or a 3.9 RV8 should make more torque below 2500rpm than the BMW 2.8. But the BMW engine is likely more than sufficient for most towing needs.

For me its the driveability of the V8's, and their associated toque that I like. Whilst the peak torque on a 3.5 may well be at 2500 rpm, it has stacks of it below and doesnt come in all.at once like a tdi or td5 does when the turbo comes in and said rpm.

That's why I referenced a V8. A tuned td5 may look like the nuts mutts on paper, but I STILL prefer a nicely tuned and maintained 3.5, it doesn't have any lag for the torque at all, there's plenty at 500 rpm for that lovely low down grunt that I just don't see would be there with a smaller 4 cylinder petrol or even turbo diesel like the tdi or td5. Even a highly tuned td5 with standard turbo is pants before the turbo comes in, its this sort of really low down grunt that I look for, but then my needs are pretty specific, living up a very steep rough track, and towing chippers and diggers very regularly.

As you say I'm sure it will be perfect for the kind of use the OP has referred to :)
 
2.8 is a straight 6 not a 4 cylinder, just for reference.

I do hear what you say, but I suspect even at such a lowly rpm a 2.8i would probably be far better than you think.
 
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