4.6 engines

[funbobby]

ive noticed quite a few griffs/chims that have gone down this route and wondering what kind of power these put out? now i know it depends a lot of what spec exactly it was done too but curious as to a ball park figure? reason i ask is ive seen a griff i like with this but the owner doesnt really seem to know so im assuming it was done before he bought it.

[dogbucket]

Assuming you mean the Rover 4.6, then that is the engine used in the chim 450.

A standard TVR one is maybe 240-260bhp (ported heads + cam). Mine made 273bhp with a 218 cam + induction kit which is similar to an average 500.

[Chimjunkie]

In Range Rover guise:

MODEL: Range Rover 4.6 HSE
ENGINE: 4.6 litre V8 petrol
CYLINDER HEAD MATERIAL: Aluminium
CYLINDER BLOCK MATERIAL: Aluminium
BORE: 94.0 mm (3.70 in)
STROKE: 82.0 mm (3.23 in)
CAPACITY: 4554 cc
VALVE GEAR: Self adjusting hydraulic tappets ohv
COMPRESSION RATIO: 9.34 : 1
FUEL SYSTEM: Lucas electronic with GEMS-ECU
MAXIMUM POWER OUTPUT: 225 bhp (166 kW) @ 4750 rpm
MAXIMUM TORQUE: 277 lb ft (376.6 N.m) @ 3000 rpm


Put a decent cam in and get 500 heads with ported and enlarged inlet manifolds/trumpets and you should get that up to the TVR figures.

[Chris71]

Out of interest, how reliable are the TVR figures? Do they tend to make manufacturers claims on the dyno?

[dogbucket]

Chris71 said:

Out of interest, how reliable are the TVR figures? Do they tend to make manufacturers claims on the dyno?

In regards to the RV8 models not very reliable at all! Deduct 30-40 bhp from TVRs figures.

Later models are more accurate iirc

[Chimjunkie]

Chris71 said:

Out of interest, how reliable are the TVR figures? Do they tend to make manufacturers claims on the dyno?

IIRC:

Engine	Real world	TVR figure
400	190-220	240
450	220-260	280
500	240-270	320

Edited by Chimjunkie on Wednesday 26th November 10:31

[AntonyJ]

I have a 4.6 waiting to go into my Griff, it has V8D stg3 heads, 218 cam and a raised compression ratio.
Will also have 45mm trumpets with ported inlet manifold, and will run with emerald K3.

Got to be a big improvement over my 216bhp 400 motor!

[rev-erend]

A lot of the reason is availability ..

Big Rangies are being scrapper.

Also - many engine builders have the new 4.6 interrim block which has several improvements over the older 4.0 pre serpentine engines, like -

4 bolt location on the crankshaft
A better oil pump

The 4.6 also uses a better grade of block from the founder..

[Chris71]

Chimjunkie said:

Chris71 said:

Out of interest, how reliable are the TVR figures? Do they tend to make manufacturers claims on the dyno?

IIRC:

Engine	Real world	TVR figure
400	190-220	240
450	220-260	280
500	240-270	320

Edited by Chimjunkie on Wednesday 26th November 10:31

I did have vague recollection of something like that, but didn't wish to assume. FWIW I'm told the original manufacturers figures for the 2.9 Ford V6 were an unusally healthy example too!

[NTEL]

Chris71 said:

FWIW I'm told the original manufacturers figures for the 2.9 Ford V6 were an unusally healthy example too!

and with a bit of work, they can be made to be very healthy!!!! Just had mine rebuilt by John Toovey of Cannock. Figures on his dyno are 250bhp at 6500rpm and 220ftlb at about 5000rpm. I'm a happy bunny

[funbobby]

ive seen some 4.6's from je developments mentioned before? im guessing if someone had put a 4.6 in then they would have done some mods prior? not sure if it puts me off the car as non original or not but if the power was good would be willing to overlook it!!

[garfys v8s]

i had a 4.6 in my v8s it was crossbolted and had a different cam and it was superb it managed 286 bhp on the rolling road at the griff growl god i miss that car.

[Chris71]

NTEL said:

Chris71 said:

FWIW I'm told the original manufacturers figures for the 2.9 Ford V6 were an unusally healthy example too!

and with a bit of work, they can be made to be very healthy!!!! Just had mine rebuilt by John Toovey of Cannock. Figures on his dyno are 250bhp at 6500rpm and 220ftlb at about 5000rpm. I'm a happy bunny

Jesus, that's quite a special Tasmin! Very healthy indeed for the V6.

To quote an old colleague of mine: "The only engine that ever made 160hp was the cert unit".

[robbri]

my chimaera is currently having a full body off chassis restoration and will also be getting a 4.6 engine upgrade with stage 3 heads i have been told that performance wise it will not be far off 5 litre performance, from memory a well respected engine builder recons a good goal to aim at is 65bhp per litre mild road cam but this could be improved on with a more wild cam.

[funbobby]

out of interest what sort of money would i expect to pay to get a decent 4.6 upgrade fitted etc?

[Chimjunkie]

funbobby said:

out of interest what sort of money would i expect to pay to get a decent 4.6 upgrade fitted etc?

Lots! RPI and Rimmer Bros offer ready to fit performance 4.6 engines for around £5k. Fitting i would guess is around £600.

[BJWoods]

garfys v8s said:

i had a 4.6 in my v8s it was crossbolted and had a different cam and it was superb it managed 286 bhp on the rolling road at the griff growl god i miss that car.

276.8bhp at this years Growl

Totally standard 98 griff (supposedly a tvr 320 bhp)

Also on a tank of 95 texaco unleaded.

B

[Meatball]

my 4.6 made 298 last year and should be a little more now

[Chimjunkie]

Meatball said:

my 4.6 made 298 last year and should be a little more now

299.5

[Meatball]

Chimjunkie said:

Meatball said:

my 4.6 made 298 last year and should be a little more now

299.5

You sod