Is anybody running a rover 4.6 engine?

[Simon]

I'm interested in peoples opinions of this engine. I KNOW it's not as powerful as a 302 may be, but if it's a nice smooth (fairly) pokey engine, I might stick with one in my GTD. Opinions please?
Thanks

Simon

[Russ Noble]

Simon,

Since no-one else seems to have opinions, here goes!

First a GT40 should have a Ford V8 in it. But in England a Rover would probably not be a silly choice and they are nice and light.

4.6's seem to be attractive because they are 4 bolted but they do seem to suffer from coreshift around the rear main. I have seen several standard motors with the rear main broken out. Depends what you want and how much you want to spend.

Unless the 4.6 is really cheap you would be better getting an old 2 bolt SD1 or Rangerover 3.5 for next to nothing and resleeving it and fitting Chev pistons and rods and a stroker crank. You can get just over 5 litres easily. And the Chev parts are reasonably cheap. Get them direct from the States.There is some other machining that needs to be done, but nothing out of the way.

The Rover heads are ridiculously small and very expensive to get much more than 300 bhp out off. But you'll have gobs of torque. Real Steel in England do oversize valves very cheaply and a set of these bowl blended with a good 3 angle valve job and a reasonable cam should have you somewhere between 250 and 300 hp. Doing the heads would be worthwhile whatever size motor you run.

RPI's website is worth a look too.

All the above IMO.

BTW the reason I decided to build a GT40 was because of the cost of getting competitive, reliable power out of my TR7V8. Once you get over 300 hp you can get approximately twice the power for the same money, and more reliably, from a Ford (or Chev) V8. This of course here in NZ where freight costs affect Pom and Yank stuff equally. In England the scales may be tipped slightly towards the indigenous engine but not enough to compensate, I fear.

You asked!

Cheers

[Ian Anderson]

Simon

Is that the one that has had a few liners slip?

Need to be top hat linered and done by the correct machine shop. Have a look on the V8 forum and I'm sure you'll find what I'm talking about!

Other than that it is a good light engine but as Russ says restricted bu valves in the head design.

Ian

[Trevor Jones]

Simon,

I am running a 4.3 Rover built some years ago by JE Engineering in Coventry.
At the time it was dyno'd at 280 hp at 6000RPM with 299 ft-lbs of torque. What was more impressive was 200 ft-lbs at 1500 rpm. As Russ said above, there is gobs of torque. I used 4 downdraught double choke Dellortos (cheaper than Webbers but look and sound the part).

The best bit as mentioned above is the weight. The all ally block and heads means that the complete engine with flywheel, clutch and induction comes in just over 330 lbs. Combined with a steel monocoque chassis the curb weight of my GT40 is 2210 lbs as measured on a public weigh-bridge.
I would gladly trade 70 hp for 150 lbs in weight in this sportscar (compared to a 302), since the lighter weight helps everything; acceleration, handling, cornering, braking, chassis stiffness, gearbox reliability.

Trevor