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3.9 to 4.6 Engine conversion

Posted: Mon May 12, 2003 11:36 am
by mickrangie
Howdy,

The 3.9 is on its last legs and I need a new donk.
I think the 4.6 is the way to go however I am getting mixed reports on the 4.6 block itself.

I have the option to get a brand new block with everything apart from injectors and inlet manifold and all I need to do is put in a new cam and the inlet manifold from my old 3.9 EFI or I can get a porus block for next to nothing and then get it repaired. Apparently when they re-sleeve the blocks they fix the cylinder that was porus with a wet jacket due to not being able to correct the original problem. I have been told by a reliable source that having a wet jacket is ok but it is an unknown resolution to the problem. What are your thoughts on the 4.6 as a reliable powerful engine? I will also be installing a wolf 4d when I do the conversion (go to hell LUCAS!!!) for engine management.
What cam would you guys suggest? Dynatech, Crow or Wade?
I have a 93ZF auto in my Rangie at the moment and the car itself has done under 150K  149 352 to exact so it is still relatively new.
I guess playing in deep bog holes will have to be kept to a minimum once the engine in replaced   
Should I be changing the torque converter to one with a lower or higher stall in it?
What other tips / tricks could you guys recommend for the conversion?

Thanks
Mick

Posted: Mon May 12, 2003 1:49 pm
by mickrangie
From what I have found out re-sleeving fixes a very common problem with the 4.6 block. Apparently Land Rover over specified the torque setting when they produced the engine originally and it causes the block to crack when it gets hot (sometimes) to resolve this in the past they repaired it with what they call a water jacket which allows water to enter the space between the cylinder and the block without any other side effects... this is more of a reactive approach to fixing the problem the proactive approach is to remove all 8 sleeves and re weld / bore the block and then fit slightly bigger sleeves with a large flare on top and O - ring. Apparently this repair method is a solution to the problem. The problem is that it costs about 2K to do the job for us retail paying plankton. :oops:

Posted: Mon May 12, 2003 6:28 pm
by landy_man
TAFE :finger: :finger: :finger: :finger: :finger: :D

Posted: Mon May 12, 2003 11:07 pm
by mickrangie
it's real engine not a lawn mower!! :P

Posted: Mon Jun 02, 2003 6:39 pm
by Aquarangie
Mick,

It's not a cheap option doing the 4.6 conversion. The higher compression model engine you will need to upgrade the Lucas Hotwire EFI system to either a Motec otr similar for it to run on regular unleaded (not a good option if you are out in woop woop!!)

Another idea is to go down the road as HSV Rangie has doome and fit up a Holden EFI. A good low mileage unit shouldn't cost the earth, plenty of grunt and plentiful supply of parts (not sure if cheaper though). And the ZF auto shoulf work a treat with the conversion.

Just something to think about. May the de-Lucasing begin!!!!

Aquarangie[/url][/list]

Posted: Mon Jun 02, 2003 6:42 pm
by mickrangie
the 4.6 should run with all my std lucas crap untill the engine is run in then the wolf 3d will get installed. I just spent the weekend in the Orange Rangie Spares rocket and the 4.6 is still on the cards if i can sell the 3.9 short motor!!