Adam001 Posted July 23, 2010 Share Posted July 23, 2010 Hey, Not technically a land rover, but I am intending to buy a range rover classic for the 3.9 V8 engine for my AC Cobra, the problem I am faced with is it must be pre 1992, to avoid emissions. So that means I am stuck with the 3.9 block...however there are no regulations on what I can do to the engine, so long as the block remains the correct age. So, begs the question, what can you do to a 3.9 V8 to make it perform much much better, any ideas welcome Thinking being the same bore a 4.6 crank and pistons might fit Discuss Adam Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 23, 2010 Share Posted July 23, 2010 Was going to compose a reasonable reply, but instead I am going to redirect you, and ask a question.... how much cash have you got? Mediocre rebuild - £1500 5.0l stroker kit, Merlin heads etc : £7K+ http://www.realsteel.co.uk/section1.pdf Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 23, 2010 Author Share Posted July 23, 2010 hmm going by those figures perhaps I should be looking at going down the yank route...hmmm Perhaps if not I could convert a older 3.9 to the newer 3.9 serp set-up with the better oil pump Quote Link to comment Share on other sites More sharing options...
Aragorn Posted July 23, 2010 Share Posted July 23, 2010 Whats the exact problem with the emissions? Quote Link to comment Share on other sites More sharing options...
zardos Posted July 23, 2010 Share Posted July 23, 2010 hmm going by those figures perhaps I should be looking at going down the yank route...hmmm Perhaps if not I could convert a older 3.9 to the newer 3.9 serp set-up with the better oil pump I seem to remember that's been discussed before, and it is a big costly change due to things like different crank lengths. Quote Link to comment Share on other sites More sharing options...
Grant. Posted July 24, 2010 Share Posted July 24, 2010 Am I right thinking that the difference between a 3.9 block and a 4 litre block are cross bolting of the block itself? And the difference between a 4 and a 4.6 is the crank, and therefore the stroke length? So...... Couldnt you, Cross bolt your block, and therefore get the appropriate internal machining done, to allow clearence for a 4.6 crank?? Then, you would have a 4.6 in the original 3.9 block. (im only speculating btw, i dont think I 'actually' know what im talking about!! ) You could even... Beg/borrow/steal/BUY(hint hint) a 3.5 off a friend, and get it machined out to 4 litre, with new liners and cross bolted, and then fit a new crank... However, none of its cheap... Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 24, 2010 Author Share Posted July 24, 2010 Screw it, i'll just go yank haha Rover seem inept at making big power unless you throw £5k at them, it's not going in a off roader so angles/water etc aren't really a problem Quote Link to comment Share on other sites More sharing options...
Aragorn Posted July 24, 2010 Share Posted July 24, 2010 Thats why i went with my Audi motor. Plus, unlike most cheap yank motors, it has nice modern multivalve cylinder head and bosch EFI etc making it pretty efficient and as economical as a big V8 can be! Why the requirement for an old engine? Is it an IVA requirement? Personally, i'd rather have a modern engine and have to equip it with a pair of cats, than a clagged out old heaper just so i could avoid it. Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 24, 2010 Author Share Posted July 24, 2010 Yes it is a IVA requirement, I don't want to faf with cats (they wont work as I will have the exhaust exit straight to the side) so will need a pre 92 engine to get around the emissions Quote Link to comment Share on other sites More sharing options...
Aragorn Posted July 24, 2010 Share Posted July 24, 2010 Plenty of folk building Locosts manage to fit cats in while retaining sidepipes... Although it might also be quite common for the cat to fall off afterwards Also IVA regulations say engines from 1st Aug 1995 require cats, engines prior to this do not. Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 24, 2010 Author Share Posted July 24, 2010 Yes but meeting the emissions requirement without a cat is near on impossible with a V8, regardless of regulation. Also I don't see twin cats being cheap either :s Have now decided to go back to the rover idea haha! Quote Link to comment Share on other sites More sharing options...
Aragorn Posted July 24, 2010 Share Posted July 24, 2010 You can buy universal cats on ebay for about 60 quid. Engines prior to 1st Aug 1995 only need to meet the "non-cat" emissions levels, which even a carb equipped engine can meet. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 26, 2010 Share Posted July 26, 2010 Not worth doing much as you have said, I'd look at throwing a more roady cam at it and obviously MegaSquirt'n'EDIS which makes lots of things nicer and should pass emissions should it be needed. The old style oil pump worked fine for the first million or so, hardly seems worth the hassle. Quote Link to comment Share on other sites More sharing options...
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