The V8 Owners Forum -

about to buy a 4.6 from a 2001 range rover. can i retrofit the sd1 front end with cam shaft to this engine.
If i can, its to replace my standard twin plenum vitesse engine giving 220.
with the right cam ( please recomend) and a hot wire system (currently using flapper type with the rover tec ecu and larger AJP? air flow meter ) What kind of bhp can i expect.
A fast respnonse would be great before i lose the purchase.
Thank you Shaun.

Shaun,

Yes you can use a SD1 front cover on the later engines but will need a spacer for the front of the crank available from RPI and others.

A cam change will help with a decent hotwire set up but the biggest improvement on the larger engines is a decent pair of heads which in standard spec are the biggest obstruction to airflow.

Power all depends on your budget but 270-280BHP is attainable without having to spend megabucks.

For road use on a 4.6 the first thing I would do would be to open up the valve seats and throats behind the valve heads and add a set of big valves that alone should get you in the 250BHP area with a fast road cam.

But it will be the big increase in torque that will put a smile on your face.

Kevin.


Kevin.

hi Kevin
Thankyou for the quick response. Reading the forum posts has alarmed me with ref slipped liners. I take it a 2001 4.6 would not have top hat liners?
how much of a problem is this?
The engine is a mint low mileage for just over 1K.
Shaun

Shaun,

Didn't want to alarm you with the liner subject, if the engine is the one from the fire damaged RR then you will probably be ok as it is being broken for obvious reasons and is not an engine that is being replaced because of the dreaded liner problem.

If you can get to hear it running that would be useful and have the plugs out and see if any of them are suspiciously cleaner than the rest, when coolant is leaked into a cylinder it tends to steam clean the the combustion area.

There is less of a problem with 4.6 than 4.0 engines as they were built with blocks with less core shift and have slightly thicker bore walls.

No standard Rover V8's were built with top hat liners which is not cheap to do, properly approx £1000 alternatively Cosworth cast blocks are available for a £1000 + VAT. and are a far superior casting.

Do make sure that the engine bay was not affected by the fire.

Kevin.

How much of a problem are the liners? is it possible to quantify say out of 100?
Yes it is that engine.
Shaun.

Shaun,

Almost impossible to quantify, the main problem was the core shift in production/casting of the blocks which is why rover had the later blocks cast by cosworth. The problem was also agravated by the fact that the 4.0 & 4.6 engines were run at a higher temp and with a leaner mixture.

If you can get the engine no. you may be able to find out whether you may be in luck, i don't know when they started using the cosworth blocks but 2001 is fairly late in production.

Kevin.

The cos block was only recently introduced to keep supply up for the aftermarket. As has been said the 4.6 used better castings than the 4.0 but they'll all go bad if left in a range rover long enough. I am told the problem was definately worse in the early cars so you may be ok. The sympoms are the same as a head gasket faliure and are easy to spot. Many garages who do not regularly deal with range rovers will diagnose the fault as a head gasket faliure and fit a new headset etc. only for the customer to return shortly with the same problem!