Thread: Rebuilding a Rover V8

I'm also in the process of building a hc 4.6 to replace my 3.9. It's early days yet but after considerable research and experience with my 4.6 SDI I've got the specs sorted:

Seasoned 9.35:1 top hat linered 4.6 block;
Piper RP4 high torque cam (it's an auto), factory lifters;
Rollmaster double row timing gears;
New regraphed dissy with RPI power amp;
Bosch ignition leads with NGK BP5ES plugs;
Reconditoned 3.9 heads (28cc), slightly skimmed with K liners;
Tornado EMS chip;
Magnaflow exhaust.

Rover Parts in Ballarat do the top hat blocks for $4.5k with crank and pistons fitted. Bruce Davis and others may also supply them ready built. The 4.9 and 5.2 blocks that TRS sell sound good on paper, but are more expensive and IMO are better suited to a TVR or race car where you can fit much bigger valves and radical headwork. A waste of money for the Disco with standard size valves which were orignally designed for a 3.5 litre bore.

Hoping for around 260hp and 320ftlb.

Originally Posted by Traco

I'm also in the process of building a hc 4.6 to replace my 3.9. It's early days yet but after considerable research and experience with my 4.6 SDI I've got the specs sorted:

Seasoned 9.35:1 top hat linered 4.6 block;
Piper RP4 high torque cam (it's an auto), factory lifters;
Rollmaster double row timing gears;
New regraphed dissy with RPI power amp;
Bosch ignition leads with NGK BP5ES plugs;
Reconditoned 3.9 heads (28cc), slightly skimmed with K liners;
Tornado EMS chip;
Magnaflow exhaust.

Rover Parts in Ballarat do the top hat blocks for $4.5k with crank and pistons fitted. Bruce Davis and others may also supply them ready built. The 4.9 and 5.2 blocks that TRS sell sound good on paper, but are more expensive and IMO are better suited to a TVR or race car where you can fit much bigger valves and radical headwork. A waste of money for the Disco with standard size valves which were orignally designed for a 3.5 litre bore.

Hoping for around 260hp and 320ftlb.

Hi Traco ;

The top hat Linered 4.6 block sounds really nice I'm still waiting a Quote from BD on a 4.6 Motor with H/C Pistons supply and fitted

Could someone please tell me if this Makes any sense , 1/4 " UNC 7/8 , Does it mean anything ? The Size of Cross Head Bolts , any idea what size socket is required ?



Are there any suggestions on how to remove the Alan key Bolts off the plenum chamber housing , They seem to be $#@% lock-tighted on ,Do they require to be locktighted

I've done mine, and i have very little mechanical knowedge (but more now ).

I didn't go all the way, so i left the block in the car. Removed virtually everything else. It was all a one man job. Took a while, but i took it slow. Only got held up on removing the crank pulley and repairing manifold studs.

I replaced heads (2nd hand, with rocker shafts), push rods, tappets, cam (not standard), timing chain/gears, water pump, exhaust manifolds, gaskets, etc. Even fitted a trigger wheel to the crank for my next project.

AFAIK, the only difference the head gaskets make is the change in compression. I removed tin ones and fitted composite ones. My reasoning was that, since i didn't machine the heads or block, there would be more "room for error" due to the type of material. Was also told (by the cam manufacturer) that the cam i bought wouldn't work properly. Runs GREAT!

Originally Posted by Traco

I'm also in the process of building a hc 4.6 to replace my 3.9. It's early days yet but after considerable research and experience with my 4.6 SDI I've got the specs sorted:

Seasoned 9.35:1 top hat linered 4.6 block;
Piper RP4 high torque cam (it's an auto), factory lifters;
Rollmaster double row timing gears;
New regraphed dissy with RPI power amp;
Bosch ignition leads with NGK BP5ES plugs;
Reconditoned 3.9 heads (28cc), slightly skimmed with K liners;
Tornado EMS chip;
Magnaflow exhaust.

Rover Parts in Ballarat do the top hat blocks for $4.5k

Hoping for around 260hp and 320ftlb.

Is that a good bit of power for a rover engine? Seams a low for a 4.5k short block that doesn't have very much power. Only saying because i got a 308 long motor a few years ago for 4.5k made just over 300 hp at the wheels with just under 450ftlb



has any one put a turbo on a 3.5 or 3.9, looked at the toyota 4.0L v8 or gen 3 in there cars? how did they go?

Originally Posted by Bulldog

I've done mine, and i have very little mechanical knowedge (but more now ).

I didn't go all the way, so i left the block in the car. Removed virtually everything else. It was all a one man job. Took a while, but i took it slow. Only got held up on removing the crank pulley and repairing manifold studs.

I replaced heads (2nd hand, with rocker shafts), push rods, tappets, cam (not standard), timing chain/gears, water pump, exhaust manifolds, gaskets, etc. Even fitted a trigger wheel to the crank for my next project.

AFAIK, the only difference the head gaskets make is the change in compression. I removed tin ones and fitted composite ones. My reasoning was that, since i didn't machine the heads or block, there would be more "room for error" due to the type of material. Was also told (by the cam manufacturer) that the cam i bought wouldn't work properly. Runs GREAT!

Hi Pete ;

I seem to have a comp leak on 1 cylinder ,see my Comp results in this thread , although I haven't done a Wet test or a leak-down test yet , but heads are coming off anyhow.

Do I have a Head problem or a shagged expansion tank cap?

the Motor has a New Cam and lifters , The engine's really smooth actually
and there is no tappet noise . like yourself , I won't be pulling the motor out to do a "complete rebuild".

I've ordered the composite gaskets today and hopefully they will arrive tomorrow. so I can continue spannering.

Just had a Look thru "RAVE CD" and found The head Bolts size it's definitely 1/4" UNC x 7/8 , so Size of the Bolt head 1/4" inch and the Thread is Course?

Edit:

Come'on someone here would know what size socket is required to get the rocker cover cross head bolts off with ??

ok, Finally after spending half the morning and travelling to 2 different Auto shops , I have discovered the cross head bolts are 1/4" drive 5/16" MultiHex Anything bigger ie 3/8" drive and the socket fouls on the Rocker cover , and neither auto-one or Repco stock them in that size , but they can be ordered which I did and probably won't be here after Xmas ,good news is the car is still driveable so the heads won't be coming out anytime soon , Until I get my hands on the right size socket.