4.6 performance spec,

[kiwicar]

Ian,
I know you are fairly commited to the rover, however, a good build on a 4.6 with a set of merlin heads, top notch rods and pistons, top hat liners a bottom end brace and a roller cam you are looking at 360 to 370 bhp if you build it (most others would be looking at 350 ) it will eat up 4.5 to 5.5K even if you source the bits carefully, and it will be a delicate beast.
A SBF on roller cam, twisted wedge heads, standad block and bottom end brace, cast crank, good rods and pistons would be five hundread to a thousand less and would see you the far side of 450bhp (built carfully) and in comparison be bullet proof.
The injection bits would transfer with a new manifold (the way the runners are on the ford you could build it yourself) and the ignition would go straight across. with the 4.6 you will be virtually starting from scratch anyway
Mike

[ian.stewart]

I hear what you are saying, Ive been thru the pricing of the Ford to a spec I would want, one of the big outlays would be the clutch, Steel flywheel, Toyota conversion bellhousing, then the stroker kit, and obviously I realise I would probably making 100hp+ more than the Rover, I am already looking at safety mods to cope with the predicted 11 second runs with the gas now, gas, +450 hp sounds like a a good giggle but it also sounds like a lot of work to get the carto be able to cope with the HP, probably need to full cage it, and possibly semi tub the rear end,

[ian.stewart]

fookin hell mate give us a fookin chance will ya

Its just a low mileage 4.6 has appeared for very little money, from a damaged RR, rather than a shifted liner engine, but I will check before I buy it, comes with a gems flywheel too, not that I want it, I will go the same system I have now, I can feel the need for flexing my Ebay account.

[Coops]

hehehehehe maybe just a 4.6 now,
its what your gona do to it im worried about

[ChrisJC]

Its just a low mileage 4.6 has appeared for very little money, from a damaged RR, rather than a shifted liner engine, but I will check before I buy it, comes with a gems flywheel too, not that I want it, I will go the same system I have now, I can feel the need for flexing my Ebay account.

If you get it and don't need the GEMS flywheel (manual), let me know, we could come to an arrangement...

Chris.

[mgbv8]

I've detuned my 90,000 mile stock RR 4.6 to run nitrous Ian. It only puts out 220bhp NASP.
But on the dyno it put out 320bhp with a 100 shot at 380 odd ft/lbs.
After the dyno I've been running a 200 shot fixed hit of gas and she runs regular 11.6's 11.7's with no trouble.

She has run down as low as 11.5's in 2008. But I'm seriously out of rpm's across the line.

So I'm just fitting bigger rear tyres.

The engine is all stock internals apart form the cam. Maybe I'm just lucky.

My 3 speed auto does sap a shed load of power though.

Perry

[ian.stewart]

What does it red line at perry??

[mgbv8]

My old 3500 ran up to a tad over 8000rpm Ian. (That was all stock internals too) But that was an accident!!. On the Dyno it went to 7400 but the BHP dropped off a while before that.

My new 4.6 makes max torque at 4000rpm on this particular build. I've only ever taken the 4.6 to 5500rpm on the track as my small rear tyres were maxxed out. There is not much BHP left above 5300rpm, and the torque is well maxxed out.

I'm not sure what the Red Line is for a RR 4.6. I only know my original MGBV8 3500 red lined at 5200 rpm on the tacho.

I'm back to square one for 2009. The bigger rear tyres should see me into the 10's if all the other bits do what they should be doing.
But I will need to take all the gas stuff back to low settings and creep it up again slowly.
Then its just a waiting game to see how long the 33 year old axle and shafts hold out eh?

[ian.stewart]

I was hoping for a few more revs on this engine, whats the weak spot, crank or rods, I dont see the crank being a problem,
Ive been watching these rods on EBay.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0282101164

Cheap security, and the pin size is not too far out,, and If they will bush the hoda Touring car pistins wont be a million miles out

[mgbv8]

Why do you want to build a screamer when the RV8 casn make poop loads of power at low rpm's??

[ian.stewart]

I want an engine that will produce plenty of power,, but be able to take 7k+so Im not losing top speed when I want it,, If I lose rev top limits I lose top speed, its got to be an allrounder but like it is now, but Quicker.

[JP.]

I was hoping for a few more revs on this engine,

I don't see the problem in doing this just put a proper cam in it, propably a custom grind.
Revs are all in the cam, just be shure you pick the right one.

[kiwicar]

Hi Ian
I don't know if you are still thinking about 6.25+ chevy rods but there are quite a few sets on US ebay at the moment,
http://cgi.ebay.com/ebaymotors/NASCAR-L ... ccessories
for 6.25,
http://cgi.ebay.com/ebaymotors/Carrillo ... ccessories
for 6.2"

http://cgi.ebay.com/ebaymotors/NASCAR-L ... ccessories
for 6.4
I did a search on "chevy nascar rods" and came up with a selection. Most seem to be for 1.88 journals which I am pretty sure are honda acura bearing size but all seem to have alot of meat around the big end so could probably be bored out to a 2" bearing.
best regards
Mike

[ian.stewart]

Ive been searching for days on there , and these popped up, and seem a better bet,
especially as the big end is a lot closer,
http://cgi.ebay.com/ebaymotors/ws/eBayI ... &viewitem=

[kiwicar]

They look nice, I presume you have a plan to use a longer piston than your first post?
Mike