The V8 Owners Forum -

Hello all.
I have a 4l rv8 in my Dax Cobra producing 182bhp and I’m thinking that I would like a little more power. My cam is an rc87 I think. I have heared I will need to move up to 4.6l. I don’t have masses of cash, sadly. Who would you recommend to build me a lively, reliable engine. I’m not looking for gas guzzling mega performance 500bhp, around 300bhp would be fine.
Your thoughts please.

Colin.

300BHP is going to be fairly expensive on that engine.

I have aimed for 300BHP with my latest build, although I have yet to get to a rolling road to see how close I am. Key points are:
- 4.6l bottom end (with top hat liners)
- Warrior heads (Stage 3) from V8 Developments.
- Stealth camshaft from V8 Developments.
- Bosch Motronic 'Thor' fuel injection (i.e. the one found in a late Range Rover P38)

So you can see there's a few grands worth. You could save a couple of grand by just getting a 2nd hand bottom end and not rebuilding it / relinering it.

I can report that performance is very lively with that configuration.

Chris.

Isn't the Thor top end better for low end torque rather than peak power, over the earlier plenum? So more suited to a 4x4 than sports car?

Ralphypants unfortunately there is no such thing as a 'cheap' 300bhp Rover engine.

Looking at ChrisJC's suggestion, which is perfectly reasonable, my first thought is that's going to start at £5k whoever you get it from.

Adjusting expectations might help you out. If you were happy with 250bhp then a 4.6 with decent cam and some DIY work on the inlet and heads would get you there.

Yes , a ball park of 250 bhp is fine. I’ve heard good reports of Ray Webb at V8 developments, can anyone confirm this?

Colin.

I got some of my stuff from Ray. No problems that I can recall. Everything OK so far...

Chris.

DaveEFI wrote: ↑Tue Jul 14, 2020 9:01 am Isn't the Thor top end better for low end torque rather than peak power, over the earlier plenum? So more suited to a 4x4 than sports car?

That is reputedly true. I stuck with it as I fancied the Motronic EMS as I've got it in my P38 and it seems very good.

We'll see how it looks on a rolling road!

Chris.

ChrisJC wrote: ↑Tue Jul 14, 2020 2:38 pm

DaveEFI wrote: ↑Tue Jul 14, 2020 9:01 am Isn't the Thor top end better for low end torque rather than peak power, over the earlier plenum? So more suited to a 4x4 than sports car?

That is reputedly true. I stuck with it as I fancied the Motronic EMS as I've got it in my P38 and it seems very good.

We'll see how it looks on a rolling road!

Chris.

Yes- the Motronic is very good. But can you get rid of the cats?

DaveEFI wrote: ↑Tue Jul 14, 2020 5:12 pm Yes- the Motronic is very good. But can you get rid of the cats?

Don't know - I kept the cats!

Chris.