4.6 into RRC..

The 3.9 in my Soft Dash range rover classic has utterly destroyed the block, by that I mean 2 large holes on each side and the last section of the cam shaft is in the sump (7 and 8) so its total scrap..

I have in my garage a 4.6 turner short block with very few miles on it. Apart from the heads and valve gear it is complete. I understand I will need to fit a camshaft that will drive the distributor, and the front cover from the 3.9.
Both engines have a serpentine blet

Will the drive plate on the 4.6 need to be swapped for the one on the 3.9 or will it bolt up to the torque converter as it is? are there any other bits I need to be aware of?

What about ECU?

Mine uses the 3.9
You need the chip as goonarmy says, or send ecu to mark adams.
Can't think of anything else.
Tin hg set if you want to retain cr with 14 bolt heads

Actually no I don't, it's on LPG which is a standalone system. I'm more interested in which mechanical bits fit the 4.6 has its drive plate still on, do I need to swap it over or can I just use the one that is on it?. The RRC is such a late one it has the 10 bolt heads (one of the final 1000) it's also not got the bolted in front panel section, all welded in fact it very different to the Haynes manual!
The other question.. is how do I get the thing out!. I want to disturb as little as possible, The RRC is an auto and I'd like to avoid taking trans cooler lines off but it looks like I have to take the engine mounts off the block to lower it so I can gain access to the bolts, does that mean they will get excessive strain? Do these late RRCs still have a removable transmission tunnel?

Any idea why the 3.9 destroyed itself ?

Yes.. conrod no longer attached to piston..
The 4.6 is now in, managed to do it with out taking the aircon apart or removing the transmission lines. It even runs! however seems to take a while after starting to extinguish the oil pressure light if its been stood from more than an hour or so. Takes a good 12 seconds for it to come on after shutdown

Which parts off the 3.9 and 4.6 did you end up using?

(Asking for a friend )

How does a RRC go with a 4.6 in it?

marccleave said:

How does a RRC go with a 4.6 in it?

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Mine went great. Even better when I binned the restrictive 40mm lpg mixer.
Fuel consumption no worse than 3.9.
If I did it again, I'd go for a more torque biased cam than the Piper 285.

Zaphod said:

Yes.. conrod no longer attached to piston..
The 4.6 is now in, managed to do it with out taking the aircon apart or removing the transmission lines. It even runs! however seems to take a while after starting to extinguish the oil pressure light if its been stood from more than an hour or so. Takes a good 12 seconds for it to come on after shutdown

Click to expand...

What weight oil are you using?
Did you renew spring washers on pickup pipe or locktite?

I had to use the sump, oil pickup, front cover, cam and distributor from the 3.9.
The oil is 20w50 and no I didn't use new spring washers.. The original oil pump was kept as this is the serpentine engine with a distributor and it seem the parts for that oil pump are a bit thin on the ground, although I do have the rebuild kit for a Thor oil pump, but not sure if the internals are the same. I did replace the o-rings on the pipes that go into the pump from the cooler. The LPG mixer is staying unless I can find an injection system to replace it with!

Had a similar problem with my 4.6 recently. I have it in a rwd car now, but it has stood for 2 years. I had the pump apart and it looked brand new. Was about to take the sump off when it cured itself. A proper oil pressure guage would be best to see what you are getting. A bit of locktite on the pickup bolts would have been good. It could also be a dodgy filter.
Pretty sure real steel stock gears and base but if your pump body is too far gone it needs a whole front cover

Hi, I had the same thing after putting a 4.6 into my 110, took a while to find but I had not got a good seal when I fitted the oil pick up from the 3.9, I stupidly re-used the gasget, well it stayed on the pick up pipe but it had gone hard. I think I may have added a few thousand miles of wear in a couple of days. Best regards Tim.

I have done a few bits since.. Replace the oil pump rotors with those from the 4.6 oil pump, as on inspection they really were not well... the 4.6 rotors were far better. I also took a look at the big ends, these were looking a bit worn, but not bad, so I have replaced those as it was apart. Now it takes 3 seconds or so for the oil light to go out on start so it's better. I also replaced the oil pickup gasket with a new one.

I do have further questions, I bought an oil pressure gauge and an adaptor for the sensor, allegedly for the V8, but it must be that the thread for the oil pressure switch has changed as it won't fit.. What do I need? this is the early serpentine engine with a distributor. I am getting a light tick from the back of the engine at idle, I've not really applied any power as its still 3.9 litre engine management (need to save some pennies for any chips, although I might just try the 4.5 litre TVR chip I have somewhere). The engine has a new std 3.9 litre cam and new tappets and rods, but the original rockers and shafts (I figured if I needed them they are not quiet so problematic to change and the old engine did not seem to have a problem in that area). Should I worry about this or wait till its actually run for more than a minute or two?