Thread: 3.9 pressureised cooling system

Originally Posted by theg

Hi all .
Got the heads off and no5 cyl is steam cleaned pretty much confirms cracked block . The liner is still in position ..
Please put forward your views .
Regards Mark

I had water leaking from the rear water jacket into cylinder 7, over time it got worse and forced water into cylinder 5, i could see the water marks between the 2 cylinders on the head gasket, also cylinder 3 was slightly steam cleaned, a friend of mine pointed out that water can be sucked in through the inlet from the crook cylinders, studying the inlet manifold confirmed this, steam cleaned on the inlet of no 3, 5 as well
Thought i had a crook block for sure but new gaskets and a stud set and all's well,
best of luck

Originally Posted by theg

Whats the difference in crank snouts ? Is it just the keyway length ?

yes

You are going to go to all that trouble to fit a motor with less power and considerably less torque. Why?
Get a second hand 3.9. I just sold a good runner with less than 200000km on the clock for $500. Plenty available from wrecked discos etc.
The 3.5 is a gutless piece of crap!

Cheers

Graeme

Originally Posted by Madkelpie

You are going to go to all that trouble to fit a motor with less power and considerably less torque. Why?
Get a second hand 3.9. I just sold a good runner with less than 200000km on the clock for $500. Plenty available from wrecked discos etc.
The 3.5 is a gutless piece of crap!

Cheers

Graeme

I tuned up a 3.5 D1 on gas last week, there's nothing wrong with the EFI version of the 3.5. It goes plenty well enouigh, about 10% down on the 3.9 but heaps more reliable in the heat.

Originally Posted by Madkelpie

You are going to go to all that trouble to fit a motor with less power and considerably less torque. Why?
Get a second hand 3.9.

Cheers

Graeme

Reason is all 3.9 motors are flawed in design with the cylinder walls too thin and prone to cracking .
Just doesnt happen in the 3.5 version .
I dont want to fit a second hand 3.9 then have to go through this all over again .

Originally Posted by theg

Reason is all 3.9 motors are flawed in design with the cylinder walls too thin and prone to cracking .
Just doesnt happen in the 3.5 version .
I dont want to fit a second hand 3.9 then have to go through this all over again .

Notes/pics from my last job, some relevant to you, here:

Fitting a '92 3.9 RRC motor into a '94

Attached a few pics to show you guys the cylinder .
Any thoughts guys?
What do you make of the cylinders either side showing some carbon cleaning aswell ?
!st pic is the worst affected cylinder and the next 2 are either side of it .

Originally Posted by theg

Attached a few pics to show you guys the cylinder .
Any thoughts guys?
What do you make of the cylinders either side showing some carbon cleaning aswell ?
!st pic is the worst affected cylinder and the next 2 are either side of it .

The engine I pulled out last week had one cylinder liner a little under 1mm lower than the rest. Can't see that with a vertical photo. This was mine: