Engine and Transmission Tech

Does anyone have a 4.6 Rover V8 either in their car or out of it?
I need to know how far the pulleys and waterpump etc protrude forward of the block please.

Either a measurement from the front of the block itself (not front timing cover) or from the front of the rocker cover to the furthest point forwards pulley wise.
My present set up in my Spitfire is a 3.5lt P6 Rover engine where I have approximately 20cm from the block to the radiator into which space fit a short nosed water pump and the pulleys with about 3cm to spare.

This engine was an unknown with regards to mileage when I fitted it and it is time for a reground crank and oversized bearings or I could just change the engine. If I change the engine I thought why not get a 4.6 from a Range Rover but I need to know how much work will be invloved, especially if I will have to rethink the radiator mounting etc.

I assume that the 4.6 and 3.5 engine blocks are essentially the same and would accept my Offenhauser inlet manifold, Carb (albeit re-jetted), exhaust manifolds, and hight torque starter etc.

Any help would be appreciated before I hit the breakers yards and Ebay :)

Graham B

Hello Graham
I would recommend buying a copy of Des Hammill's excellent book "How To Power Tune Rover V8 Engines" I got a copy from Amazon for less than £12. Despite the title there is a lot of very use full information on various Rover V8 variations with sections on carburation and fuel injection. The blocks are essentially identical in dimension but the latest blocks had cross bolted main bearings The serpentine engines have a longer crankshaft (about 20mm) , a different oil pump and lack of a distributor drive to contend with. How ever you can fit the earlier front covers to shorten the engine, and with a new camshaft with the gear to drive the distributor and oil pump you are back to the original length. Or you could Megajolt the engine and keep the serpentine front end, the permutations are endless.
Philip

Thanks Philip,

I did a bit more research on the web after posting and realised that the 4.6 would not have a distributor, and would have coil packs and electronics etc. My installation is more retro with a four barrel carb and a bug scoop through the bonnet, which I am more inclined to keep. I appreciate that the 4.6 can be modded to a certain extent to get back to this state of play, but perhaps I should be looking at a 3.9 which would have a distributor and be a simpler block swap.
I have read somewhere though that some of the 3.9's had cylinder problems? which was cured by the later top hat liners?? Anyone know which are the ones to look for and which to avoid? and again I would initially need to know how far the pulleys etc protrude from the front of the block.

Cheers

Graham B

You don´t have to worry about the ancillaries. All you need to do is to swap the bottom end and use the existing stuff from your current engine. That´s what I did years ago with one car.

4,6 engines had liner problems or actually the block cracking underneath the liner. Buying a s/h block is a gamble, top-hat linered blocks are supposed to be permanet fix if properly done.

4,6 in a Spit makes an interesting package. Go for it !

Hi Jukka,

I'm interested by your comment about "swapping the bottom end" can you explain what you did?, do you mean swapping the block and being able to keep all ancillaries or is there some way of just swapping crank and pistons to gain more cc's/bhp?

Cheers

Graham B

Graham and clan, I'm not positive if the 3.9 has large main journals, or not. If it does, the 4.6 cranks should fit. Internally balanced and the crank driven oil pump is best. If you find "any" block has the liner, receeding from the deck,"pass" as this is likely cracked behind the liner. Having a prospective block, pressure checked, is good insurance.4.0-4.6's are quite sturdy, I had a customer run 22lbs of manifold pressure/briefly. This was stock pistons, that were thermal and skirt coated. NOT reccomending silly-high boost with stock parts ! Cometic head gaskets are available, and do the best job, for performance builds. Cheers, roverman.

The 3.9 has the same crank as the 3.5 (or Buick 215). So, the answer would be no.

Graham, bottom end includes block, crank, rods and pistons. So this is what you take from 4,6 engine. Heads are supposed to be slightly better so they are worth using if your existing ones are not that special. Everything else from 3,5 engine. Use a cam for 3,5/3,9 type engines. Serpentine engines without dizzy have physically a bit shorter cam. I am not sure about the can in the intermediate engines (crank driven oil pump / dizzy) but older type fits anyway.

The only necessary part in this conversion is a short spacer that needs to be fitted in the crank snout. This is available e.g. From Real Steel, part no DW525