3.5 crank into 3.9?

[Outlaw]

Okay looks like i may have a cracked crank on my 3.9... no oil pressure and won't go :( don't ask:eek:

So if the engines buggered considering i just had it serviced a couple months back with new injectors etc... do you know if a crank out of a 3.5 will fit a '98 3.9v8

Cheers in advance.

[incisor]

:eek:

who did you run over?

bloody hell man....

[loanrangie]

Same stroke and journal size so should be ok but you will virtually need a full bottom end rebuild to fit it.

[harry]

what have you done josh?
run over a chinaman?

what makes you think the crank is sick?
yep 'don't ask', doesn't work with me.

[Pedro_The_Swift]

Love to know the symptoms of a cracked crank!!!
:o:D

[Outlaw]

full loss of oil pressure with a bit more driving afterwards... all from overfilling with oil :(

Now don't i feel like a loser :( a v8 disco is worth nothing even when running... so anyone want some parts :p

[harry]

bags the transfer case, auto, front diff and rear diff, engine and all the other stuff.

[CraigE]

Get a 4.2 stroker crank.:D

[Scouse]

full loss of oil pressure with a bit more driving afterwards... all from overfilling with oil :(

This is interesting - just how "overfull" ?

There's a 3.9 with a blown head gasket on eBay ATM & I know someone who has a short motor for sale (but it's in Sydney).


You are also more than welcome to the crankshaft out of my 3.5 RR motor as that's getting stripped down shortly.
Free but you'd have to pay postage.

[Outlaw]

about 15-20mm over the full mark... maybe 1.5L

[Scouse]

about 15-20mm over the full mark... maybe 1.5LIf that's the case, I really can't see that being the cause of your problem IMO.


Are you sure it's a crankshaft issue?
Does the front pulley rotate when turning over the motor? If not, then that might indicate a breakage & therefore not turning the oil pump.

I've seen a few oil pumps fail but never a crankshaft (in my experience at least).

[Freestyler]

As far as I know the cranks are the same. The bore is larger. I have a number of 3.5 engines here if you want to check it out.

[Freestyler]

I have also had a crankshaft fail tearing number 1 main bearing out of the block. I have also heard a comon fault with these engines is the main cap bolts comming loose therefore losing oil presure. Easy to check just drop the sump off.

[UncleHo]

G'day Folks :)

Rover V8 motors are also known to snap cranks from Cross-Firing, caused by crook insulation on the plug leads, 5 & 7 from memory, "Scouse' may be aware of this as it was a known fault and cause of crank breakage, I remember that from a service school talk 20+years ago

cheers

[Scouse]

I remember that from a service school talk 20+years agoJust how old do you think I am ?? :p:p
20+ years ago I was in nappies.





OK, so it was 20+20:twisted:.

I have been around Land Rovers for only 18 years :cool:. I remember the JRA testers talking about the bearing cap bolts coming loose after sitting on a certain engine rev for 12hrs at a time :eek:.

[p38arover]

Maybe this and do a bit of swapping:

AULRO Classifieds - Message - Powered by PhotoPost Classifieds (http://www.aulro.com/apc/showproduct.php/product/1464/cat/9)

I'd like it to transfer my daughter's 300Tdi into.

[Lucus]

i have a 3.9 short motor with a dropped liner that probably bound for the tip. I'd take donations of beer for it. Only problem is that its located in perth

[djam1]

Found this on the net it might help

3.5.=89.5mm bore Std 3.5 crank
3.9.=94mm bore Std 3.5 stroke crank
4.2.=94mm (3.9 bore ) plus and 4.2 longer stroke crank
4.0 is the same capacity as 3.9 but uses later big journal crank and is cross bolted
4.6. + 94mm bore ( As per - 3.9 & 4.0) but uses later big journal (long stroke) crank and is also cross bolted as is the 4.0.

[Grimace]

Josh 15mm over full isnt much... 30mm on the other hand is. I dont mind givin you a hand to drop the sump and have a look.

A bottom end rebuild will be on the cards if something suss is discovered.

[loanrangie]

Also, dont the later 3.9 's have a longer crank snout to drive the oil pump in the timing cover ?

[Outlaw]

might take you up on that Grimace so we have more of an idea... will probably wait till after the house move though :D

[graceysdad]

Could be a badly cast crank that has finally given up, does happen, sounds like a motor out job, usually plenty of 3.5s on flea bay, bad luck man.

[Taz]

Outlaw, you may want to look for signs of the 'black death' on the journal registers of the main bearings of your block before you invest more money into it. According to Des Hammil, once this happens the block is done for. Aparantly this is one of the main reasons why the non cross-bolted mains blocks die, the other being cracks behinds the linings on any of the 94mm bore blocks. Black death is where the bearing block has rubbed against the journal register indicating that the block is loose and will allow the crank to warp.

[PLR]

Okay looks like i may have a cracked crank on my 3.9... no oil pressure and won't go :( don't ask:eek:

So if the engines buggered considering i just had it serviced a couple months back with new injectors etc... do you know if a crank out of a 3.5 will fit a '98 3.9v8

Cheers in advance.

G`day ,

Physically fit , only difference may be the weights .

Bradtot would tell you ( if asked nicely ) if they added extra weight to his when he had 3.5 made into 3.9 x2 . ( Hi Brad )

Cheers