Dan88 Posted January 5, 2011 Share Posted January 5, 2011 I'm wondering about swapping the 3.5l v8 fOr maybe a 3.9 or 4.2, from what I hear the 4.2 had their fair share of woes? Thanks Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 5, 2011 Share Posted January 5, 2011 Toyota 1uz Quote Link to comment Share on other sites More sharing options...
Quagmire Posted January 5, 2011 Share Posted January 5, 2011 v8forum.co.uk - Helpful chaps. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 5, 2011 Share Posted January 5, 2011 A lot of bashing goes on of anything bigger than the 3.5 - liner slip is a common one that "they all do", but I reckon it's mostly exaggerated by those who have 3.5's and are a bit jealous The "best" Rover one would be the 4.6, but they're all basically the same engine so take your pick based on what your wallet says. The 4.0 & 4.6 were cross-bolted which is nice to have but not essential. Ultimately there's no right answer though, and I'm sure there will shortly be (another) long argument about why the 3.5 is superior. Quote Link to comment Share on other sites More sharing options...
jagwit Posted January 5, 2011 Share Posted January 5, 2011 I'm wondering about swapping the 3.5l v8 fOr maybe a 3.9 or 4.2, from what I hear the 4.2 had their fair share of woes? Thanks What is the best V8? The cheapest one? The most reliable one? The most economical one? The most powerful one? etc If you are going to fit another engine, fit the 4.6 and be done with it. They do have issues (so I'm told) but have yet to experience one having those issue myself - not that I have had very many 4.6s under my hands. Quote Link to comment Share on other sites More sharing options...
Dan88 Posted January 5, 2011 Author Share Posted January 5, 2011 The 3.5 I have is on a edelbrock 4 barrel carb, I wanna run on LPG. I would like the new engine to be quite quick, and reliable. Not overly complicated and I'm not bothered about economy. If the 3.5 isn't worth swapping I will LPG that, I just read that the carb wouldn't be as good as a efi. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted January 5, 2011 Share Posted January 5, 2011 Chev mouse. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 5, 2011 Share Posted January 5, 2011 The 3.5 I have is on a edelbrock 4 barrel carb, I wanna run on LPG. I would like the new engine to be quite quick, and reliable. Not overly complicated and I'm not bothered about economy. If the 3.5 isn't worth swapping I will LPG that, I just read that the carb wouldn't be as good as a efi. Well, you're right - the carb is a shocker, I'd have a read up on megasquirt (see tools'n'fab forum) as that will make things much nicer especially with LPG. May also be worth checking your engine's compression ratio etc. as older 3.5's can vary by 50hp depending on what spec they are, easier to buy a complete 3.5 or 3.9 EFI MOT fail Rangey and have the whole lump than rebuild one though. Your question is still a very open one - define quite quick? A 3.5 in good nick will be lively enough in a landy compared to things like TDi's. Quote Link to comment Share on other sites More sharing options...
davie1 Posted January 6, 2011 Share Posted January 6, 2011 The 4.6 is an overboared 3.5, the block can crack causing the liner to slip that is why there is the top hat mod. Also heard that the 4.6 and the 4.0 block can become porous. Could be wrong but think the SD1 vitesse 3.5 had a stiffened block, some one on hear will know. Davie Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 6, 2011 Share Posted January 6, 2011 The 4.6 is an overboared 3.5, the block can crack causing the liner to slip that is why there is the top hat mod. Also heard that the 4.6 and the 4.0 block can become porous. Could be wrong but think the SD1 vitesse 3.5 had a stiffened block, some one on hear will know. Davie If you want to be really anoraky about it, everything bigger than 3.5 is overbored, and some are also stroked, full table of geekness is here: http://www.roversd1.nl/sd1web/capacity.html Quote Link to comment Share on other sites More sharing options...
landy V8 Posted January 7, 2011 Share Posted January 7, 2011 have a word with "V8 DEVELOPMENTS" They really know there stuff about these engines and will help you out a lot. Quote Link to comment Share on other sites More sharing options...
g&t Posted January 8, 2011 Share Posted January 8, 2011 A lot of bashing goes on of anything bigger than the 3.5 - liner slip is a common one that "they all do", but I reckon it's mostly exaggerated by those who have 3.5's and are a bit jealous Jealous of what exactly Apart from being the most reliable engine all but possibly the last 3.5's were built before LR decided that it could get away with marketing a top of the range product whilst using thinner/cheaper steel in the process. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 8, 2011 Share Posted January 8, 2011 Jealous of what exactly Erm, 50% more power torque perhaps? If you ignore internet hearsay the other lumps don't seem to go wrong any more than the 3.5's do. I'd wager the main difference is that when a 3.5 goes wrong they're so common and cheap that no-one bats an eyelid about just binning it and sticking a new one in for £200, whereas when a later one has problems they're still worth money so can lead to more expensive repair jobs and hand-wringing threads on internet forums. Given that 3.5's were fitted alongside 3.9's and 4.2's for quite some time I don't think you can really claim any difference in production quality there, and the later 4.x ones were the same basic thing but with a few improvements and modernisations, some of which people used to pay a lot of money to have done to the old blocks for racing (cross-bolting for example). Granted certain other things happened later (eg compliance with stricter emissions rules) which added complexity in engine management and more stuff stuck to the block, but that's true of any vehicle built at the same time and doesn't really have anything to do with the oily bits. Quote Link to comment Share on other sites More sharing options...
g&t Posted January 10, 2011 Share Posted January 10, 2011 Erm, 50% more power torque perhaps? If you ignore internet hearsay the other lumps don't seem to go wrong any more than the 3.5's do. To quote your 'Erm, 50% more torque? when I left school nearly 50 years ago that much increase would endow the 3.9 with a torque of 309 lbs/ft - I bet you wish! Having had to replace a block due to liner slip you could say that I'm somewhat bias, as indeed is a mate of mine who experienced the same problem. There is also an opinion held that 3.5's were balanced by the fitment of matched sets of pistons etc. as opposed to the later method of balancing the engine post assembly by fitting weights to the crank pulley. The problem of liner slip in the larger capacity engines was initially kept very quiet by LR until main dealer demands for replacement blocks exceeded supply, then the cat was out of the bag Yes I agree that a few more horses to shift two tons would'nt go amiss, but if you use the car in the manner for which it was conceived the 3.5 is generally adequate for the job. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 10, 2011 Share Posted January 10, 2011 3.5 on carbs vs 4.6 on EFI would be 50% more for sure Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 10, 2011 Share Posted January 10, 2011 My 2p worth If looking at standard engines and Rover breed then I would say the best unit is a late serpentine 3.9. Better oil pump, crossbolted block, and a squarer stroke makes free-er reving vs longer stroke, and liner issues rare (not unknown), coupled with Megasquiirt = IMVHO best bet for bucks Nige Quote Link to comment Share on other sites More sharing options...
g&t Posted January 11, 2011 Share Posted January 11, 2011 3.5 on carbs vs 4.6 on EFI would be 50% more for sure Sorry, perhaps I've lost the plot. I thought Freezer was comparing a 3.5efi with a 3.9 when I replied. The thing is that manuf's output figures alone don't tell the whole story. Not only did the later 'classics' put on weight but they also had slightly taller high range gearing than those (like mine) with the LT230T transfer box. Quote Link to comment Share on other sites More sharing options...
zim Posted January 14, 2011 Share Posted January 14, 2011 The answer is simple : Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 14, 2011 Share Posted January 14, 2011 The answer is simple : It's simple if you're after big power numbers for cheap, but any non-LR conversion brings a lot of hidden costs and pitfalls. Nothing that can't be overcome, but not a straight swap either. I agree that if you can't get what you need out of a standard-ish Rover 8 then you're far better dropping something yank in that makes the numbers out of the box than spending thousands tuning a Rover till it squeaks, but it's not as easy as the swap from one rover V8 to a bigger one. Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted January 14, 2011 Share Posted January 14, 2011 I swapped a 3.5efi (tired one I admit) for a 3.9 and the difference was noticeable, i found it pulled better at lower revs which helps for offroading IMO. Was going to strip and rebuild the 3.5 but after feeling the difference the 3.9 made I didn't bother. Might turn it into a coffee table A friend had a 3.5 converted to a 5.0 by v8 developments for a kit car, good work and nice people but more than I would be willing to spend on an offroader. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted January 15, 2011 Share Posted January 15, 2011 My 2p worth If looking at standard engines and Rover breed then I would say the best unit is a late serpentine 3.9. Better oil pump, crossbolted block, and a squarer stroke makes free-er reving vs longer stroke, and liner issues rare (not unknown), coupled with Megasquiirt = IMVHO best bet for bucks Nige I'd agree that the later serpentine engines are some of the best. I'm not sure about the numbers regarding stroke/bore but the oil system is far better and IIRC the blocks can be drilled for cross-bolting because they were made using 4.0 blocks. Manufacturing had improved at this point and blocks were measured for wall thickness, one of the factors leading to block cracking was the cores slipped during casting leading to unequal thickness in the metal at either side of the cylinders. 4.6 engines were made from the best blocks BTW and if you find blue spots of paint on the block behind the pushrods (IIRC) then it's one of the best blocks, yellow and red being the other colours. The relatively low power output of the 3.5 is another reason they seem to last longer, partly due to a less agressive cam which tolerates timing chain stretch a bit better. One thing that did not improve with the bigger engines is the exhaust note, the longer stroke and cam timing meant that the exhaust pulses overlap more, smoothing out the sound. Be honest, that's why we like V8s, right Personally my favourite is my 5.0, though it's getting ready for having a few quid chucked at it, new cam/chain/lifters and a new 'box. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 16, 2011 Share Posted January 16, 2011 What would be the point of buying a late 3.9 and cross-drilling it like a 4.0 rather than just buying a 4.0 then? Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted January 16, 2011 Share Posted January 16, 2011 None really, other than the internals are all from the 3.9 or 4.2 rather than the 4.0/4.6 which would make a difference if you were rebuilding one. I don't know if these later blocks are inherantly stronger. If I rebuild my LSE then I'll have it crossbolted. Quote Link to comment Share on other sites More sharing options...
g&t Posted January 29, 2011 Share Posted January 29, 2011 One thing that did not improve with the bigger engines is the exhaust note, the longer stroke and cam timing meant that the exhaust pulses overlap more, smoothing out the sound. Be honest, that's why we like V8s, right Just out of interest, I've read that the earlier carb-fed V8's produced a more pronouced burble than the EFI's. Picking up on your post, does the 'duration' have a bearing on this effect as I notice that the 3.5 carb version is 280degrees whereas the 3.5efi is 256degrees. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 29, 2011 Share Posted January 29, 2011 I'd take an extra 30bhp over a slightly improved exhaust note any day Quote Link to comment Share on other sites More sharing options...
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