Rover 3.5 V8 N/A 1970 engine. Want 300bhp!!

[RayC1985]

Hi guys

I have decided to tune a Rover 3.5 V8 engine out of a Rover SDi that’s in a kit car Formula 27 (Westfield / Caterham style)

I am not a novice to engines and I own a repair garage, however I am a novice to how best tune this engine to 300bhp without going round the houses and spending money that I don’t need to.

The engine came in the car with a 4 barrel Holley Carb and is up and running, all be it a rebalance and tune of the Carb is needed.

I have no problem taking the engine out completely and starting from scratch however I do need some proper advice on what parts to place and particularly which make and models.

Thanks guys

[Sardonicus]

That's going to be a damned expensive build I'll tell you that, do-able yes but ..... From a 4.6 displacement far easier

[Glasgowrob]

cheaper option with much more reliability and potential.........

https://www.ebay.co.uk/i/283565788965

or if you want do to ultra budget build


https://www.ebay.co.uk/itm/Jaguar-S-Type-4-0-V8-Co...

[RayC1985]

Thanks for your input guys. - food for thought

[RayC1985]

Also would like to change the fixed rear axle to an LSD with active axle but god knows where to start

[anonymous-user]

300 bhp from 3.5 litres is 86 bhp per litre.

Today, that's nothing special really, but it's going to be hard on an old 8v push rod engine with carbs and clock work ignition.

If you really want 300bhp, then you need a large capacity engine as mentioned. Otherwise, we are probably talking spending something like £25k on your engine to get it to make a genuine 300bhp. Feeling rich?

[stevieturbo]

4.6 to 5.0 option, good heads, sensible cam, exhaust, the usual st. fuel injected etc... ( although it could be done on a carb/carbs too )

300bhp should be very achievable, but will cost a few grand alright.

[RayC1985]

That’s the thing, there would be very little labour cost as I would be able to do 90% myself.

It’s what parts are best to buy etc etc that I need knowledge of?

Are there decent gains to be had by removing the heads, send the heads away for porting and polishing et ? The. Replacing cams with Kent or something similar, then fitting high comp pistons blar blar Blar.

Best place to source these parts would also be good to know as there are a lot of makeshift “specialists” out there

[Boosted LS1]

Decent pistons and a turbo will be king. Otherwise spend a fortune on broken valvetrain parts and the associated misery.

[Belle427]

I’d agree that a 4.6 engine would be a better place to start unless you plan to boost it, will still be fairly expensive though as heads and a nice cam would be a must.
Real steel are the only company I’ve used that I would not hesitate in using again, some of the other big players in the V8 circles I’ve found to be hard work.

http://www.realsteel.co.uk/

[Sardonicus]

stevieturbo said:

4.6 to 5.0 option, good heads, sensible cam, exhaust, the usual st. fuel injected etc... ( although it could be done on a carb/carbs too )

300bhp should be very achievable, but will cost a few grand alright.

Agree with this ^ and labour is not your worry but knowledge and parts the later not cheap tuning the RV8 is not a cheap process sadly , and just chucking in a spiky cam and mediocre modified heads wont get you there

[fttm]

Some of the clubmen rally boys used to drop a Buick crank in , instant 3.9ltrs iirc

[Boosted LS1]

Or just use a rover 94mm block.

Buick cranks need larger main journal shells and external balance plus have a dodgy rear seal iirc.

At least rover redeveloped this stuff, shame we never got race buick v6 head designs.

[AER]

Take it as standard down to a rolling road dyno. You'll get at least 300hp instantly!

[Steve_D]

Find yourself a TVR 4.5 or 5.0 engine...job done.

Steve

[v8bloke]

I have used this engine in my track MGB. Gone from standard SD1, then 4.0L then 4.6, 4.8 and now 5.0L.
In my opinion best bang for buck is 4.6 engine fitted with 4.0L pistons. mech 238 cam self ported heads with larger valves. this will get you 290bhp/torque.
My present 5.0L makes 380bhp 400 ft lb but same spec would cost upwards if 12K
here it is in action.
https://www.youtube.com/watch?v=oApIXsibs6M

[anonymous-user]

Steve_D said:

Find yourself a TVR 4.5 or 5.0 engine...job done.

Steve

What he said.
Cost me thousands to get 315bhp from my 4.2 lump in my Westfield. If doing it again I would find an old decent tvr plus t5 box.

Mike

[bucksmanuk]

The original TWR Group A Rovers struggled to get over 340 BHP, and that was with a truly enormous budget and some “exploitation of the rules”, and we’ll leave it at that. Cheating is such a dirty word…
Get as much capacity as you can, so 4.6 litres an obvious choice.
TVR Tuscan heads are the way to go. They add 50-60 BHP onto the engine almost no matter what the specification. Finding some, and in good condition, is another matter.
As above 86 BHP/litre is nothing today but getting a reliable 145 BHP out of a 1600 X/Flow (the same 86…) cost me a LOT of money in 1988. 2V head, Pushrods, single trick DGAS, clockwork ignition - I like that term…
Cheapest horsepower is always cubes – no replacement for displacement.
A 302 Ford would easily get 300 BHP – if not 350 BHP. A good mate had one in a MK2 RS2000, and that went like stink….
S-type 4.0 Jag as above is an excellent idea. 286 BHP straight out of the crate. Fuel injection, sensible specification. The 3 litre V6 version would probably be just as good and loads of them too.
Turbo(s) etc… is effective
http://www.beardmorebros.co.uk/website%20pages/inf...
But who would you ask in 2019 to get it sorted out and running sensibly?

As an aside- another mate wanted a Westfield Seight. He looked at a TVR-engined 5.0 litre version at Terry Nightingale’s place. This was built money no object and thought to be around the 400 BHP mark. Terry took him out in it, and admitted it was far too much for the road, and he was scared to push it.

He bought one with a 3.9 V8 - probably 250 BHP. I don’t mind fast cars, but that was best described as “urgent”. He let me drive it a few times - You had to be in the right mind set to drive it, and it caught you out VERY quickly. He thought he was a driving god, but he only ever went out on a wet road once.

I can second Real Steel are good people to deal with

[GreenV8S]

bucksmanuk said:

He thought he was a driving god, but he only ever went out on a wet road once.

If you've got enough tyre to cope with that power in the dry, it must be absolutely in the wet.

[bucksmanuk]

Its difficult to describe what it was like when you were accelerating and overtaking, and if it had 4 wheels, you overtook it - you couldn’t help but sit there and laugh. It sounded great too- instant “oh wow-s” from fellow petrolheads turning into a pub car park that had a beer garden.

My size 10’s were too big for the pedal area so I drove it with just socks on, but it allowed a lot more feel on the pedals.

What got me was that you had to be so incredibly careful changing down and match the revs precisely. A slight mis match on the engine speed and road speed would make the back tyres chirp (sticky 235’s) due to the engine compression braking. This occurred in normal suburbia with us just gently making our way back home. I sussed out that doing this on a damp road while “making progress” would be as bad as a slight tweak on the handbrake.

The car required a definite change in driving technique from anything else I’ve ever driven. I think 300 BHP will prove more than plenty.