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Discussion Starter · #1 ·
Does anybody know if the late 3.9 motor with the serpentine accessory belt and crank-driven oil pump still needs a spacer to use the 3.9 pulley on the 4.6 crank? I know the earlier v-belt equipped 3.9s have the shorter crank 'snout' necessitating the use of the spacer, but I'm sure I've read somewhere that the late 3.9 crank pulley can just bolt straight up to the end of the 4.6 crank (of course I can't find that particular web page now!). Thanks!
 

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yes, regardless of the belt drive style vee or serpentine, you do need the spacer because the 4.0/4.6 crank is too long.
RPI used to sell one. I have used old crank timing gears and ground down the sprockets, also have used the small drive sleeve out of a crank driven oil pump. this you don't have to grind as they are a straight fit.
on a 3.9 serpentine engine the harmonic balancer was damaged, the conversion engine was a gems thus it used a long stem balancer, I clocked and marked the new (gems) balancer timing marks and used it with out spacer as it had been a straight fit.
bottom line if reusing/tranfering your existing harmonic balancer you need about and inch wide spacer.
 

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Discussion Starter · #3 ·
Perfect, thanks for the confirmation and also for the oil pump drive sleeve tip!
 

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Slightly different point about the job you are about to do: Have the cylinders been "top-hatted"? I would hate to see you do so much work only to get liner slippage in the future. Sure it will add a lot to the cost but you will not regret it. The 4.6 block with 3.9 heads is a superb combination in terms of performance - I know - I have one
 

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Discussion Starter · #5 ·
I hear ya, and I know that's how it should be done, but I can pretty much guarantee that top hat liners and the associated machining would cost more than I paid for the Rangie, which is a bit of a mutt if I'm honest! This is kind of the last roll of the dice before I cut my losses and give up on her for good.
 

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You are absolutely correct about the cost. I got lucky because the PO of this 93 SE had done the engine conversion and added dual fuel at a cost of over $12k. Fortunately, he had also rebuilt the air suspension.

I bought the car for $5k It has cost me around $3k to fix all the other things like the seat switches, heater resistor pack, air con, tailgate latches, A-frame bushes, central locking, clear-coat damage, chipped internal veneer, seat stitching and most recently the alternator that had been bolted back on even after the casting had broken. None of these jobs were life threatening - just silly hassles but the vehicle is a joy to drive - that 4.6 conversion is superb

Hang in there - just enjoy it!
 

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Slightly different point about the job you are about to do: Have the cylinders been "top-hatted"? I would hate to see you do so much work only to get liner slippage in the future. Sure it will add a lot to the cost but you will not regret it. The 4.6 block with 3.9 heads is a superb combination in terms of performance - I know - I have one
Is this conversion simply a case of fitting the 4.6 crank and pistons to a 3.9 block or have I misread that?
 

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Is this conversion simply a case of fitting the 4.6 crank and pistons to a 3.9 block or have I misread that?
BigJ, All depends what you have and what you wish to accomplish, a 4.2 is a stroked 3.9, a 4.6 is a stroked 4.0
4.6 and 4.0 blocks have cross bolted mains as 3.9 and 4.2 do not. this being said all affore mentioned blocks share the same piston bore size.
the crank journals on the 4.0 and 4.6 are the same thus you could have a good 4.0 and find 4.6 internals thus now you have a 4.6.
same goes between the 3.9 and the 4.2... to answer your question, no you cannot fit 4.0 or 4.6 internal to the 3.9 or 4.2 blocks, the crank journals on the 3.9 and 4.2 are smaller thus do not accept the 4.0, 4.6 crank.

either way you go if you install a stroker kit on your block 3.9 to 4.2 or 4.0 to 4.6 you will gain lots of torque and enjoy its new found performance, specially if you add a custom cam to the equation.

if you end up procuring a 4.6 you need to keep in mind the 4.0 and 4.6 did not use a distributor, thus you need to install a cam made to fit a distributor drive gear in order to keep using your distributor, all else is very much switch over from your engine to the 4.6 until we come to the harmonic balancer.
the crankshaft front on a 4.0 or 4.6 is longer by about an inch thus the spacer mentioned by the O.P., at the rear of the same crank you need to remove the timing dowel, so you can fit your fly wheel or flex plate.

if you have an auto box more than likely it is a zf 22. once the 4.6 is in situ, you need to be easy on the throttle as the zf22 does not like the new found power of the 4.6. if your zf22 auto box has more than 150,000 miles it is highly suggested for it to be refreshed.
it will fail soon.
 

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BigJ, All depends what you have and what you wish to accomplish, a 4.2 is a stroked 3.9, a 4.6 is a stroked 4.0
4.6 and 4.0 blocks have cross bolted mains as 3.9 and 4.2 do not. this being said all affore mentioned blocks share the same piston bore size.
the crank journals on the 4.0 and 4.6 are the same thus you could have a good 4.0 and find 4.6 internals thus now you have a 4.6.
same goes between the 3.9 and the 4.2... to answer your question, no you cannot fit 4.0 or 4.6 internal to the 3.9 or 4.2 blocks, the crank journals on the 3.9 and 4.2 are smaller thus do not accept the 4.0, 4.6 crank.

either way you go if you install a stroker kit on your block 3.9 to 4.2 or 4.0 to 4.6 you will gain lots of torque and enjoy its new found performance, specially if you add a custom cam to the equation.

if you end up procuring a 4.6 you need to keep in mind the 4.0 and 4.6 did not use a distributor, thus you need to install a cam made to fit a distributor drive gear in order to keep using your distributor, all else is very much switch over from your engine to the 4.6 until we come to the harmonic balancer.
the crankshaft front on a 4.0 or 4.6 is longer by about an inch thus the spacer mentioned by the O.P., at the rear of the same crank you need to remove the timing dowel, so you can fit your fly wheel or flex plate.

if you have an auto box more than likely it is a zf 22. once the 4.6 is in situ, you need to be easy on the throttle as the zf22 does not like the new found power of the 4.6. if your zf22 auto box has more than 150,000 miles it is highly suggested for it to be refreshed.
it will fail soon.
My motor has just clocked up 135k miles and as far as I know everything is original so I assume the auto box etc are all the factory components. I’d rather keep the originals and refurbish them when the vehicle gets its full restoration in the next year or so.

It sounds from your answer that upgrading to the 4.2 would be best for me to retain the original box etc but I thought I’d read somewhere about the unreliability of the 4.2 engine in particular cooling issues related to cracks or liners? Can’t remember exactly but I don’t want to introduce unreliability into the car so might need to investigate this further.

One other query, is it possible to upgrade from a dizzy to a coil pack on the 3.9?

Appreciate the feedback, cheers.

Joe
 

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My motor has just clocked up 135k miles and as far as I know everything is original so I assume the auto box etc are all the factory components. I’d rather keep the originals and refurbish them when the vehicle gets its full restoration in the next year or so.

It sounds from your answer that upgrading to the 4.2 would be best for me to retain the original box etc but I thought I’d read somewhere about the unreliability of the 4.2 engine in particular cooling issues related to cracks or liners? Can’t remember exactly but I don’t want to introduce unreliability into the car so might need to investigate this further.

One other query, is it possible to upgrade from a dizzy to a coil pack on the 3.9?

Appreciate the feedback, cheers.

Joe
Joe, I have always commented on how these trucks are supposed to be built to cross the hot sahara, yet they run hot and fail just sitting in city traffic oh how ironic...

the reality of it all boils down to maintenance, when new the dealer did the specified maintenance which was for the first 3 yrs or 36,000 miles. just the borderline recommended cooling system maintenance. if it was done at that time we never know. then as the years go by we do not notice the aging process, eventually component such as fan clutch fails, followed by another, thermostat maybe.
by this time the same coolant has been there forming electrolytes, rust and corrosion related issues. the mechanic ignores the warnings and simply replaces the worn out or failed components. by now the vehicle is some 10 plus yrs old and all we do is repair to keep going, not maintenance.
then one of those faithful days with a/c on in rush hour traffic the vehicle runs in to red and because of our location we cannot save it. all it took was less than a minute and its gone.
the steel piston cylinder has expanded the aluminum block and the engine is toast. then we blame the engine as junk but it was our fault all along due to poor periodic maintenance.

long story short installing 4.2 internals to your 3.9 block will not cause early failure. always make sure to stay on top of your cooling system maintenance, including professional clean not flush of the radiator.

the next inquiry is yes you can swap from dizzy to coils, in the uk you have so much support for custom on rover engines, tvr's, morgans are just a few forums which offer info on all aspects including procurement of parts, installation and tune.
rimmer bros, rpi, are a couple of customizers and engine builders whom offer support.

here in the states, it is a bit harder as only parts are offered, and you need to mix and match... no support for rover engines only ford, gm and lately some mopar.

I have been looking into DIS conversion on my lwb, my interest comes and goes.

I have had a custom 4.6 in my classic for nearly 10 yrs and some 70,000 miles, have crossed many of the concerns we have been discussing. my fortitude lies in my aptitude as rover mechanic, thus I have been able to save lots of labor costs and apply them to research and parts.
my next project is the install of a ford v8 coyote engine in lieu of the rover v8. for no other reason than the truck being a toy.
best of luck in your endeavors.
Carlos.
 

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Enjoyed the information in this thread, thanks for taking the time Carlos!
 

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you're welcome, my pleasure to share as much as I can based on knowledge and personal experience.
 

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Hi Carlos

Thanks for your detailed reply. Just one further point on the fitting of 4.2 internals to my 3.9 block. Would doing this increase the chance of the liners slipping and causing the overheating issues or is the chance of this happening the same between the 3.9 & 4.2?

You do have me thinking about the 4.6 now though but it sounds like a different auto box would also be needed to cope with it. Is there a direct replacement for the ZF22 that I could fit?

Could I just retrofit a P38 4.6 engine and box to mine using the correct ECU?
 

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Joe, hi. no overheat issue so as long as the engine swap includes a good radiator clean/recore or new radiator, not just cooling system flush. needless to say thermostat as well.
if you are wanting to install a stronger outbox you could use the zf24 out of the p38 or the late d2 (2003-04), if you go this route you will need to keep in mind this unit is fully electronic, thus it needs a controller by the name of compushift supplied by Ashcroft Transmissions. this negates the need for land rover transmission ecu.
yes you can retrofit a p38 power train, if so then you need to reuse the back housing of the zf22 (governor cover) the transfer case on the p38 rides left all other rovers ride right.
detailed instructions on ashcrofts's website.
one more detail in regards to the engine, since rovers take the rpm signal from the alternator. if you do the stroke to 4.2 or replace to 4.6 you will need an alternator drive pulley for the stroked engine as your rpm's will be slightly off.
 

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...I have been looking into DIS conversion on my lwb, my interest comes and ..
I thought this was your coyote dream...btw, the mopar hellcat is now available...
Sorry for the rabbit trail...


Sent from my iPad using Tapatalk
 

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I thought this was your coyote dream...btw, the mopar hellcat is now available...
Sorry for the rabbit trail...


Sent from my iPad using Tapatalk
yes, coyote dream. but in the meantime reliability and difficulty procuring proper factory replacement ignition parts has me wanting DIS ignition.
don't even go there with hellcat, I though I had the driveline figured with ford or gm now mopar, a whole new game...
 
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