My 4.6 V8 Rebuild Thread

[101RRS]

I now am almost ready to start assembly. The block is ready, the crank is ready, I have the bearings, I have the ARP studs for head and main, I have the gaskets, I have the Crow Cam and I have the rings. I just need to get the 4.0 pistons on the 4.6 rods - matching lengths and weights.

Cost so far - shipping included.

• 4.6 block, crank, pistons and rods - Free courtesy of a generous AULRO member
• Top Hatted 4.0 engine - a couple bottles of Bundy from a generous friend and AULRO member
• Block welding - $110
• Block helicoil - $55
• Block work and crank machining - $593
• ARP Head studs and main studs - $439.34
• Gaskets and bearings - $495.11
• Rings - $228
• Crow Cam - $360.80

So without actually putting anything together costs so far are around $2300. So the costs do mount up.



After the block is assembled, I will need to get the heads levelled (shaved), new lifters etc, and a new cam chain etc and on it goes.


On other forums the conclusion is that the Gems injection system will be better than the Thor for day to day running as it is a bit simpler. Also the general thought was that performance over all was similar but the Thor has better lower end torque but a bit less at the top end which is not what i want. The Gems ECU (input wise) is a lot simpler.


Once I start assembling I will post up pics as I go along so you cam all tell me what I am doing wrong .


Garry

[PLR]

G`day Gary ,

suggestions , if your aware of following good and if not get yourself a manual . ( may be on web " LRL 0164ENG " is the factory V8 overhaul manual to 1998 )

The pins are offset , the pistons only face one way , the rods have a boss ( little dimple ) one side , the piston face to or away the boss depending on which bank ( 4 face to and 4 face away ) .

There is a known batch of faulty rockers , you`ll see a # on them , i have it somewhere just need to locate .

When you get to heads there are some basic #s that will tell what has been done as in if machined , as above .

Cam timing dot to dot works if your lucky , if you want to set as the card says you`ll need a degree wheel ETC .

If you have the std rover rings they will be chrome and you will need to run it in on petrol to run/bed it in . I`d suggest not running it on LPG untill it stops using oil .

I`d be surprised if you can`t hire/lend the special tools needed , dial gauge , degree wheel , tension wrench ETC . No real need to buy unless you intend this often .

The Aldi $40 one would probably be ok for the inlet and timing cover ETC .

Peter .

[MacMan]

Cam timing dot to dot works if your lucky , if you want to set as the card says you`ll need a degree wheel ETC .

I can't over emphasise the importance of checking this properly. DON'T assume it's all good to go dot-to-dot.

[101RRS]

G`day Gary ,

suggestions , if your aware of following good and if not get yourself a manual . ( may be on web " LRL 0164ENG " is the factory V8 overhaul manual to 1998 )

The pins are offset , the pistons only face one way , the rods have a boss ( little dimple ) one side , the piston face to or away the boss depending on which bank ( 4 face to and 4 face away ) .

There is a known batch of faulty rockers , you`ll see a # on them , i have it somewhere just need to locate .

When you get to heads there are some basic #s that will tell what has been done as in if machined , as above .

Cam timing dot to dot works if your lucky , if you want to set as the card says you`ll need a degree wheel ETC .

If you have the std rover rings they will be chrome and you will need to run it in on petrol to run/bed it in . I`d suggest not running it on LPG untill it stops using oil .

I`d be surprised if you can`t hire/lend the special tools needed , dial gauge , degree wheel , tension wrench ETC . No real need to buy unless you intend this often .

The Aldi $40 one would probably be ok for the inlet and timing cover ETC .

Peter .

Thanks have the genuine rebuild manual - also aware of the correct way pistons etc go back in. The heads as they have low use will be going back in as is with just a clean up.

Thanks for the pointer on the LPG - as the injection system will be made up there is a chance it will not run first up and because of the specific requirements of running in the cam I was going to run it on gas. I might initially put on the carbs and run the engine in on them and then change over to injection.

Thanks for the tips.

Garry

[PLR]

Thanks have the genuine rebuild manual - also aware of the correct way pistons etc go back in. The heads as they have low use will be going back in as is with just a clean up.

Thanks for the pointer on the LPG - as the injection system will be made up there is a chance it will not run first up and because of the specific requirements of running in the cam I was going to run it on gas. I might initially put on the carbs and run the engine in on them and then change over to injection.

Thanks for the tips.

Garry

G`day Garry , i don`t think it would be a problem to do the initial cam run in on LPG .

The reason for not using LPG in the initial bed in stage is because it doesn`t produce the same amount of carbon as running petrol .

Could be said , the only time the wearing characteristic of petrol is useful .

[101RRS]

I have not been doing much on the engine due to other priorities however I have been thinking about induction. I haven't made up my mind as yet and would prefer to do the installation with a system I know. Hence initially I will stay with the CD175 carbies until I have the engine run in and basically sorted and then move to whatever system I consider appropriate - indeed if I get the desired performance I may even stay with carbs.

So what will I need to the carbs to go from 3.5l to 4.6. Obviously needles and jets but what is the best way to determine the required sizes etc. Put in to a carby expert with my requirements and let them sort them? Put the carbies on and then change and upgrade as part of the tuning process - dyno or electronic analyzer. A bit difficult on a 101 as it is hard to get under the carbies to change/adjust jets. Would a good start be setting the carbies up with the same jets etc as the carbies on a 6 cylinder series engine as each carby on the 4.6 is looking after 2.3 litres vs the 6 cylinders 2.6litres.

Also I will be fitting LPG rings between the carbies and manifold and these restrict the intakes to 30mm diameter at the ring so will this have any impact on the jets and needles chosen for the 4.6.

I am not sure we have too many carby experts here in Canberra so advice on who might know what would be required in the Sydney area would be appreciated.

Thanks

Garry

[Pedro_The_Swift]

Gary when mine was at the build discussion stage I told Richard from Turners that it would run LPG 90% of the time and he suggested using the 4L pistons to bump up the comp ration to 9.7. (That and a good head shave was enough for me)

[101 Ron]

As you know Garry I will be watching this thread with interest.
This time you are leading the way.
If using dual donuts/spacers just be fore the carbies , I would try them as is.
These days you will need a oxygen sensor, or a hand held aniliziser fitted and use the readings to set up both petrol and gas.
Usually the donuts can be opened up a little bit in a lathe if needed.
As you may know I play with engines that need to bed in the rings on gas only.
This can be done in my experience with Hastings brand rings.
For some reason they work well with LP gas.
The gas will run the motor as is without tuning problems.( other than some easy adjustments)
I would find some spare CD strombergs and use the jets out of the spare carbys or use the spare carbys to play with.
Keep the 3.5 carbies as a reference point.
On the spare carbies you can make a mistake and it will not be a big deal.
I would drill out the main jet with a number drill , just very slightly larger, ( just the smallist amount).
Then I would try and drive the thing using the air/fuel ratio measurement from what ever means as a guide and by the way the vehicle drives.
1/4 to 3/4 throttle is by the needle and this is changed by placing the needle in a chuck of a drill and using some emery paper reduce the diameter of the needle where needed.
It should be noted the standard 101 jetting is much richer than a 3.5 rangerover motor, as the 101 was over fuelled from the factory so the motor would still perform while working very, very hard on poor fuels.
There is a chance if you still have standard 101 jets and needles very little may need to be done.
My 101 is running early range rover needles and jets as it saves a lot of fuel, and a lot of 101s would have had the same treatment.
If all else fails, find a dyno.

[bee utey]

I have not been doing much on the engine due to other priorities however I have been thinking about induction. I haven't made up my mind as yet and would prefer to do the installation with a system I know. Hence initially I will stay with the CD175 carbies until I have the engine run in and basically sorted and then move to whatever system I consider appropriate - indeed if I get the desired performance I may even stay with carbs.

So what will I need to the carbs to go from 3.5l to 4.6. Obviously needles and jets but what is the best way to determine the required sizes etc. Put in to a carby expert with my requirements and let them sort them? Put the carbies on and then change and upgrade as part of the tuning process - dyno or electronic analyzer. A bit difficult on a 101 as it is hard to get under the carbies to change/adjust jets. Would a good start be setting the carbies up with the same jets etc as the carbies on a 6 cylinder series engine as each carby on the 4.6 is looking after 2.3 litres vs the 6 cylinders 2.6litres.

Also I will be fitting LPG rings between the carbies and manifold and these restrict the intakes to 30mm diameter at the ring so will this have any impact on the jets and needles chosen for the 4.6.

I am not sure we have too many carby experts here in Canberra so advice on who might know what would be required in the Sydney area would be appreciated.

Thanks

Garry

Will you be fitting the LPG rings under the throttle plates? Won't work with a regular LPG converter as full manifold vacuum will be applied to the gas inlets at idle.

My rule of thumb with LPG mixers on D1 style engine intakes is that a 42mm ID single mixer works on a 3.5/4.2 engine and a 46mm ID works on the 3.9/4.0/4.6 family. If you fit gas rings to the top of the carbies then you coud as Ron said machine them out a little in a ratio similar to 46/42. The mixer bore size required depends mainly on the peak airflow rate generated by each cylinder in turn.

For example a 4.2 Holden V8 requires a bigger mixer than a 4.4 P76 as the latter has a smaller bore. A 6 cylinder 3.3 Falcon uses the same mixer as a 4.1 as they share a bore size. A 4 cyl 2.6 Magna uses a bigger mixer than a 3.3 Holden.

[101RRS]

Gary when mine was at the build discussion stage I told Richard from Turners that it would run LPG 90% of the time and he suggested using the 4L pistons to bump up the comp ration to 9.7. (That and a good head shave was enough for me)

Doing that - it does not go up to 9.7:1 but about 9.1:1 - 4.6 with 4.6 Hi Comp pistons is 9.35:1.

Cheers

Garry