Which performance heads would you choose?

[Precat]

I'm building a 5.2L engine with a V8D Stealth cam for road use. No track days. I have a choice of performance heads,
V8 Development stage three heads with 1.63 inlet and 1.4 exhaust valves or TVR 500 heads with 1.69 inlet and 1.45 exhaust valves.
Which performance heads would you choose and why?

Thanks in advance

[GlynMo]

TBH, with the state of the roads in the UK, the number of fixed/mobile cameras, the crowded roads etc, what's the point if you're not doing track days?! A standard Griff (any) is fast enough to lose your licence if you're not very careful.

[A900ss]

You can never have too much power even if only for the road

I'm interested to know the answer as well. I've got a 450 with a stealth pushing out 273hp but I feel its power drops off too quickly so needs better breathing. The inlet manifold and plenum would need to be increased but not sure of the the best heads to go with them.

Edited by A900ss on Saturday 14th March 15:52

[Wildfire]

V8 Developments heads here on my 4.0.

[Quinny]

In my view the porting is far more important than the 0.05 difference in valve size.....

[carsy]

Quinny said:

In my view the porting is far more important than the 0.05 difference in valve size.....

Agree completely.

Its a nice choice to have. As to which are the best flowing i dont know.

I suspect the V8D ones are still on the standard valve seats. It doesnt leave much meat on the seat.

The TVR 500 heads will have had bigger seats fitted ( i think ). Job done properly to accomodate the big valve.

Edited by carsy on Saturday 14th March 18:08

[Hoover.]

an interesting poised question

[stesrg]

I had a company called cylinder head developments do my heads on my 4.3 I went for the biggest valves possible and cut 3 way also loads of porting and polishing , this made a vast improvement in power but I did go for a fast road cam and adjustable push rods and high rev followers with eprom chip she used to rev to 7200 !! :-)
Well worth it in my opinion ( also some plenum work and forced air intake )
Thought I would go the turbo route this time ?
Ste.

[Andav469]

I agree with the above, decent porting and calve seats will yield greater results than a tiny increase in valve size.
mine is a V8 developments 5.0 engine giving a decent result.
I'm still running on the 14CUX, so still some more to be had

[SILICONEKID345HP]

V8D 5l with a Stealth cam and 500 fly wheel .I`m not sure if the heads are three or four .Its running on the Emerald ECU

[Alexdaredevils]

Interesting to see those two graphs side by side, one has more average torque one peaks out right at the end more than the other, one on emerald ecu one 14cux

[phazed]

Daz, you have stage 4 heads.

to the OP whoever you are, fork out for stage 4. heads.

[Andav469]

Alexdaredevils said:

Interesting to see those two graphs side by side, one has more average torque one peaks out right at the end more than the other, one on emerald ecu one 14cux

Interesting indeed, so the 20hp difference is for 500rpm and the torque on one peaks and drops quickly, obviously could be dyno differences/different day etc but I expected more if going for an aftermarket ECU,

Edited by Andav469 on Sunday 15th March 08:49

[Quinny]

Stage 1, stage 2, stage 3, and stage 99.9999 it's all pub BS anyway

One mans stage 2 head is another mans stage 4.........

[Hoover.]

just as a thought the TVR world keep going to the same names........ just wondering if there is more out there in RV8/V8 tuning world that may do something a bit different that might offer a better package, as there is a whole kit car world out there

[leerdam23]

ITBs are the way to go, with a nasty overlappy cam....breathing at high rpm but no shunt from cross contamination...imho

[Andav469]

leerdam23 said:

ITBs are the way to go, with a nasty overlappy cam....breathing at high rpm but no shunt from cross contamination...imho

Completly agree, it's just starts to get expensive when FI gives you a minimum 100bhp in one go

[Sardonicus]

Have a talk to Peter Burgess he knows the RV8 cyl head very well and tells it how it is and dont bullst ... http://www.burgesstuning.free-online.co.uk/

[Quinny]

Knowing precat.........he'll end up putting the V8D head on the 1,3,5,7 bank and the TVR head on the 2,4,6,8 bank

[Precat]

You could be right Quinny
The best of both worlds