which is better

ok so i totally have o idea so here is the poll which is the better engie the 3.5 v8 or the 3.9v8

I have both.

the 3.5 is tougher and will have less mechanical issues and last better on lpg but the 3.9 has more torque and without tuning more horsepower.

I really think for longevity the 3.5 is the way to go. however the 3.5 efi is crap compared to the hotwire on the 3.9.

alot depends on the brummie who built the individual engine and if he had to do it with a hangover or on a friday, also how worn the tooling was by that point.

we are not talking bmw stndard quality though unfortuantly :doh:

I am sure all on here will have there own opinions though.

I had no problems with my RR 3.5 untill a new 3.9 shot past me going up a hill. Now have a disco 3.9 and still no problems.

discool said:

I had no problems with my RR 3.5 untill a new 3.9 shot past me going up a hill. Now have a disco 3.9 and still no problems.

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:lol:

I am surprised 3.9 is doing so well with all the liner/HG probs on lpg.

I do like mine though, need to spend more time in the 3.5 to see

The design of engines is not my thing but I understand the 3.9 is a tougher engine additonal webbing, bolts etc. but ok untill they overheat for what ever reason.
I had 10 happy years 94,000 miles with my RR 3.5 but it did smoke on startup in the morning and the cam was noisy when I sold it.

discool said:

I had no problems with my RR 3.5 untill a new 3.9 shot past me going up a hill. Now have a disco 3.9 and still no problems.

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Did you have the handbrake applied on the 3.5 Seriously though, I've had both sizes engines in RRC's (all auto's) & can honestly say that I've not been aware of any noticeable difference in performance during normal driving. I do know that the only 3.9 I had slipped a liner at around 90k & that's not an isolated incident.

Never been in a 3.5.

But I love my 3.9. Goes like stink for a Land Rover.

More power. Plus better fuel economy with the 3.9 aparantley.

Heard that a lot of problems with overheating and liners is due to LPG kits being fitted and running lean. Doesnt cool the engine properly.

hammoj28 said:

Never been in a 3.5.

But I love my 3.9. Goes like stink for a Land Rover.

More power. Plus better fuel economy with the 3.9 aparantley.

Heard that a lot of problems with overheating and liners is due to LPG kits being fitted and running lean. Doesnt cool the engine properly.

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It dont need lpg to overheat or drop the liners

lol , yeah thats what I have heard.

I said all I wanted to in the first post but I cant shut up as I love v8's too much lol

nathan5346 said:

It dont need lpg to overheat or drop the liners

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Nope, it certainly doesn't but it can contribute to it.

i have run a 3.5 and a 3.9 and a 4.2 and never had a problem with any of them as i had removed the cats and the lambdas which help contribute to the running lean and over heating causing the slipped linner problem.
3.9 ok
4.6 how a v8 should have been

ive read loads of probs to do with running on lpg. i have a iweama kit on mine. it was fitted nearly 8yrs or so ago now at 75000 on the clock and its only had 2 owners since it was fitted long owners too and its now done just shy of 120000 and its still strong on the gas and petrol could alot of thease problems be cause of bad setting up of the lpg in the first place and cheaper kits. i dont even notice a drop in power when running on gas.
maybe its just cause its a V8 i do luv it so specially when some jacked up oil burning disco dont clock the V8 badge and tries to see me off at the lights

hammoj28 said:

Nope, it certainly doesn't but it can contribute to it.

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Maybe maybe not, the 3.9 lpg i had was a single point fitted in 2000 with 20 odd tho mile on it and it was still top notch when i let it go with 105,000 i can only go off that one

vougese39 said:

i have run a 3.5 and a 3.9 and a 4.2 and never had a problem with any of them as i had removed the cats and the lambdas which help contribute to the running lean and over heating causing the slipped linner problem.
3.9 ok
4.6 how a v8 should have been

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i want to bin the cats when i put a stainless system on for my xmas pressie what do you have to do to take the lambda sensors out of the equation im not an electrician and electrics scare me i know a little but that makes me dangerous so i just dont touch them, can do a nice job of spot lights though lol

change the tune selct resistor.

make sure it will pass an mot without them

nathan5346 said:

Maybe maybe not, the 3.9 lpg i had was a single point fitted in 2000 with 20 odd tho mile on it and it was still top notch when i let it go with 105,000 i can only go off that one

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I guess it must be to do with setup, prob the ones running to lean to recoup money back on the kit.

Is it normal that my 3.5 on 33" x 12.5" tyres running 30psi will struggle to pull past 50mph on the motorway if on the slightest incline?

Tbh it's difficult to get it going fast on the level, and downhill it hardly "accelerates" !

I "think" it's running properly, but tbh I can't remember what it was like on standard Tyres...

It seems fine in first second and third, just uselessly powerless in 5th gear.

Cheers, sam.

you see what happned to clarkson in bolivia when he fitted the bigger wheels and tyers? It "ruined" his range rover

Yeah, i remember.

Must just send that gearing too far out.

Ideally i would like to fit HD low ratio ring and pinions, because onbiously i also find that my crawl speed is affected.

Cheers, Sam.