Thread: Swap 3.9 for 4.4.

1. Your flywheel will need to be machined and drilled to suit the back of the P76 crank.
2. You will need manifold spacers to keep the EFI as the P76 has a 20mm higher cylinder block each side.
3. The engine mounts will need the block drilled/tapped to suit the LR mounts (which may need to be welded to make them longer).
4. The crank will need a longer keyway to suit the '95 front cover oil pump.
5. You need to use the LR heads to mount all your accessories as the P76 had only block mounts for alt, a/c and p/s pumps.
6. The rocker gear will be fed oil through the hollow P76 push rods unless you drill the block for the oil galleries to the heads. The castings are there on the P76 block.

Cheers for that, I have most of those things covered. I wasn't sure about the engine mounts or the flywheel. Can I use the P76 flywheel?, and I think there may be an issue with the starter motor. I can only go by what's on the net till I dig in and gety hands dirty.

Originally Posted by Disco95

Cheers for that, I have most of those things covered. I wasn't sure about the engine mounts or the flywheel. Can I use the P76 flywheel?, and I think there may be an issue with the starter motor. I can only go by what's on the net till I dig in and gety hands dirty.

The LR flywheel is easier to machine than it is to adapt the LR clutch to the P76 flywheel. It is also heavier and more suited to off-road. It is only a small cut out of the centre hole and then you redrill the P76 bolt holes between the LR ones.

You will need a spacer ring to use the LR starter in the P76 engine. A very common conversion as the P76 starter is archaic, Lucas-made and hard to get bits for.

Originally Posted by bee utey

The LR flywheel is easier to machine than it is to adapt the LR clutch to the P76 flywheel. It is also heavier and more suited to off-road. It is only a small cut out of the centre hole and then you redrill the P76 bolt holes between the LR ones.

You will need a spacer ring to use the LR starter in the P76 engine. A very common conversion as the P76 starter is archaic, Lucas-made and hard to get bits for.

You can get away with outusing a spacer ring for the starter , I ran a 4.4 in a 86 highline with a LT77 with no dramas for a few years

Thanks for that guys.
I have also read that the P76 pistons are prone to cracking but can be replaced with either Holden 173 pistons, or Rover 3.5l 8.13:1 (I think) pistons.
As I will be doing a full reco should I be considering these options?

Originally Posted by Disco95

Thanks for that guys.
I have also read that the P76 pistons are prone to cracking but can be replaced with either Holden 173 pistons, or Rover 3.5l 8.13:1 (I think) pistons.
As I will be doing a full reco should I be considering these options?

Rover 8.13 pistons will give you the best result as they will raise your compression to around 9.5:1 with the 20% extra stroke of the P76. The 173 pistons are a poor compromise, used only due to the high cost of rover pistons 20 years ago.

Thanks for all the info guys, I'll be hooking into it this year. I'll keep you all posted.

I understand the 4.4 is not real good at sustained high revs - I had considered going a 4.4 for my 101 but am now heading the 4.6 route.

This high revving issue was in the back of my mind where I was down in the upper Murray river area over the past few days - Tom Groggan, Davies Plains, Geehi etc where on roads like the Alpine way etc my 3.5 was sitting on 4500 rpm for long periods during steep climbs (4500rpm, 25kph and climbing at 1m per second in vertical height) - would have a 4.4 been happy in those circumstances.

But then as someone said, that given the extra cubes and torques of the 4.4 over the 3.5 it most likely would not have to be revved so much.

But the 3.5 does like to rev and sounds so sweet in a 101 just a few more torques would be nice.

Cheers

Garry