The V8 Owners Forum -

im an old owner of a V8, its been sitting in my range rover for the near on 3 years i owned it, its been recently rebuilt with fresh block and top hat liners 8-9k miles ago and has been kept tip top.
im new as in just decided i want to modify it.
the question is how much power can i safely push with standard internals on a 4.6 rover V8!
i want to NOS it and would like to get the standard 225hp to 350hp, maybe a touch optomistic but i dont know!

if you dont know ask, i was once told!

thanks in advance.

You can push a shed load of gas through these old V8's if you do it right Red.

My old low comp 3500 runs a 150 shot all day long with no probs. And she returns 1/4 mile runs of 12.4 seconds in my MGB.

But when I up it to a 200 shot she melts pistons. I think I've got that sorted now and will see if my theory works late in 2008 when I debut my V8 Fiesta running my old 3500 engine and MGB running gear.

I've now stuck a 4.6 in the MG and with a 100 shot she brought me in a 12.08 second pass on a cold track.

Both of the above are with all standard internals.

Dont try to get decent performance with the Holley Nos systems. They do work, but they wont give you the performance you want.

For instance. On my old 3500 I was running a twin cheater plate system from Holley. A 50 shot on launch, then a 100 shot on the button from second gear. This gave me a best of 12.8 seconds on the strip.

I changed to the WON / highpower systems plate setup and running their system with a 100 shot of gas brought me in a regular 12.4 second pass on my old low comp 3500 which I could repeat day after day at the Pod.

You should check out and join Trevs website at "The wizards of Nos" for more info mate.

I reckon I'll be well into the 11's in 2008 with my new 4.6 engine.

Perry

so im guessing that 100 shot to take me to 325hp would be ok with the big and main bearings!!
its not going to be used big time, just a little more grunt away from a standing start and it prob wont be often either, its something i always wanted to do!
the block is cross bolted, i been asked to check as this helps, and the whole engine is only 8-9k miles old and in tip top condition, oil changed every 3k miles as well.
hopefully il get a nice smile from another 100hp, im usually smilling anyway.

thanks for the reply.

Chucking gas into your engine, the last of your worries will be your bottom end. Because you’ll not be revving it any higher, the crankshaft loads won’t be an issue.

You can throw a 50 or 75 shot into the engine without even thinking about the consequences. At 100, you’ll just need to make sure that the timing is correct, your plugs are in good condition (you may need a slightly cooler plug) and the nitrous mixture isn’t at risk of being lean. For 150, you may have to retard your ignition degree or two if you’re using the gas low down the rev range.

To be honest, you will be amazed at what a 100 shot gives you. It’s not just the power, but the torque and the ‘area under the curve’. Simple thing is, you’ll get a whole lot more acceleration and grin factor from 100bhp of nitrous than you will from the same power in super/turbo charging or conventional normally-aspirated tuning.

And , as MGB V8 says, use WON/Highpower stuff. A little more expensive, but that’s because it’s superb quality as opposed to the agricultural American stuff. And, because it uses the gas more efficiently (you get more boost for longer from a bottle), it’ll cost you less in the long run.

excellent news, i know about cooler plugs as i run them on my supra already, bcrp7es instead of 6's, ignition may be difficult to change as it aint got no dizzy! its the coils pack thingy. i run normally on lpg and therefor my plug gaps are smaller than normal, 0.7mm instead of the 1.0-1.1mm for petrol, would this cause a problem with nos?

Red
Did I mention that you should buy Trevor Langfields book. That will tell you pretty much all you need to know about using nitrous safely.
You can buy it on line from the WON shop, or you often find them on ebay.
It was the best purchase I made before changing from Holley to WoN.

I have a dissy ignition and I've fitted as remote advance / retard unit so i can dial in the timing I want for what ever shot of gas I'm using.

Trevor and his team will guide you through the installation or they will do it for you if you want. Very helpfull bunch.
Go online this evening and join the forum. See you there!!!
Perry

I forgot to mention.
The WON nos plate system on my Weber 500 gave me an increase of 77bhp on the dyno when using their 50hp jets.
The jet rating does not really equate to the actual gains you get. Imagine you are using the 50hp jets. But you could be using them on a 1000cc jap motor or a big 706 yank block.
The actual power gain depends on the setup you have. Thats why its best to start small and try to get in on the rollers for a test.
As SE says, the torque gain is a real blast. Once my foot hits the floor the system kicks in and the big grin starts...