The V8 Owners Forum -

Hi all

I am toying with the idea of getting a 4.6 warrior engine for my P6, anyone had any experience of this engine?

Richard

Hi Richard

I'm not aware of anyone on the forum running one of Rob's Warrior engines.

All I have to add is ensure that you get exact specs for what is being offered, i.e. valve sizes, flow rig data, etc, and satisfy yourself that you cant get the same or better for the same dosh or even less.

Would the final drive survive the extra torque? It's not got a lot in reserve.

Thank you Rossco, will heed that

Hi Dave, the original diff was wearing rather badly and showing signs of giving up, so I shoehorned an XJS one in there, that should handle it ok

Who else is there to get a quote from? I can't really get on with RPI, and don't know anyone else.

I am looking at other options, including getting a 4.6 crank and conrods, and converting my 4L to a 4.6. Just fancied a fully balanced engine with a pair of decent ported heads. I will be porting the injecting system as well to match.

Richard

To be honest I'd stick with the 4.0 and invest in a good cam and heads. You should be able to get a solid 250bhp out of that which should make the P6 move a little.

Alternatively I can build you a Buick 455 but that might over stress pretty much everything

I'm getting just under 220bhp at the moment, and 268lb/ft of flywheel torque, so 250bhp would be nice.

I have a 4L cross bolted block, stage 1 heads from RPI, RP4 cam, 4 into 1 tubular headers, custom stainless exhaust, hotwire EFI and EDIS controlled by MS1, all running through a 5 speed LT77, custom prop and XJS LSD.

I was thinking about replacing the crank with a 4.6L one, and having it, the con rods, pistons etc balanced. I did wonder if the stage 1 heads from the 4L would flow enough to satisfy the 4.6L block, so looked around and found the warrior heads. I then found I could get a 4.6 long engine fully balanced complete with warrior heads and fast road cam all fully built and ready to go - hence my original question.

I do rather fancy building my own though, so how would I go about getting 250bhp from my 4L?

Warrior heads (or similar) stealth cam (or similar), and maybe a ported EFI system?

The RP4 will be the most significant limiting factor in making more power. My experience of that cam is that it is a bit limited at the top end where you really need it to be strong if 250bp is the goal.

My recommendation would be to go with a Crower cam, probably something like the 53233 with a set of Rhoads lifters to keep the bottom end tractable. Alternative I would to talk to Mike at TA Performance and see what he recommends. I'm guessing either the TA284-88H or the TA290-94H would be Mike's suggestion. Upping the compression by a point or two should also be possible and will make a few more bhp.

As for heads. The truth is that the Rover heads are very limited in terms of what can be achieved with them. The real life differences between any stg1 and the so called stg4 heads is not much. The ones you've got are as good as some and better than most, so without spending a fair chunk on something like TA Performance heads then I'd stay with the stg 1's. Lets not forget that a stg4 head only really comes into it's own at high rpm, and will trade off some bottom end due to a drop in inlet velocities. So unless you are looking for high rpm (above 6500rpm) stick with the stg1's, you can always have the stg1's fettled later on if you want more top end.

If you're dead set on a 4.6 crank I've got a few in the workshop but all will need a regrind. Can't help with pistons unless you want to change the rods and go with forged pistons. To be honest though I dont see that as the easiest way to achieve what you are looking for.

Just my thoughts, I'm sure someone else will have a differnt take.

Cheers Rossco

Not sure what to do yet, will do more research, then maybe take you up on the crank offer

Richard

Where in Yorkshire are you?

Just off the M1 at J34, near Meadowhall.

Not so far then. I'm just around the M6 toward Ull

Your RPI heads cant be up to much there are stock TVR spec (mild cam) standard headed 4.0 fitted to TVR RV8 models making 220/240- (healthier) HP these are Lucas Hotwire engines just fitted with large tubular manifolds and free flow exhaust system , just to give you a bench

I did have a go at this, removing the engine back in February and stripping it down to its last nut and bolt.

I got a local v8 engine specialist to balance the crank, flywheel, clutch cover, and front pulley. He also did the pistons and rods.

I found an engineering shop to fit top hat liners, seemed silly to have the bare block and not do this.

V8 Developments took the heads out to Warrior spec, machined the pistons to take the higher lift cam, supplied a Stealth cam, timing set and adjustable push rods, plus all gaskets and running in oils and additives.

I rebuilt the engine and put it back in.

750 miles now covered and it's very smooth running. Not fully run in obviously but during a rolling road session to set up the higher revs on the megasquirt, it was producing 265bhp and 284 lb/ft of torque, so very satisfying.

Nice result. Surprised it's not knocking out a little more though..?

Chris.

There's still time