Engine build

[Ralphypants]

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.

[ChrisJC]

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.

[DaveEFI]

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?

[Rossco]

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.

[Ralphypants]

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.

[ChrisJC]

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

Chris.

[ChrisJC]

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.

[DaveEFI]

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?

[ChrisJC]

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

Don't know - I kept the cats!

Chris.