Gas flowed head / ported head / big valve head

[matth76 0]

Hi

 

I was looking at Stealth's website and they seem to specialise in rebuilding and also uprating engine cylinder heads - one way is to "gas flow" it. How much does this normally cost and are the power / torque gains worth it? Does it improve low down torque as opposed to top end power?

 

I assume a 'big valve' head is different to a gas flowed head? And what is a ported head? What are the costs and power gains for each?

 

I've got a Golf VR6 (ODB2).

 

Thanks for any info.

 

Cheers

Matt

[flusted 0]

gasflowing a 16v head normally costs approx £500.A big valve is is the same as a gasflowed head but it has larger valves machined to fit in it

Best bet is to get both done

Hope this helps?

[rmn 0]

Not sure how much you can do a big valve head conversion on a vr engine, as the piston is dished and the valves sit flat in the top of the head.

As for gas flowing, on a 12v vr6 it makes huge differences as the port design is quite restrictive.

Anything that makes you car breather better will improve power and drivability in my opinion.

Hope this helps somewhat

[mgbv8mike 0]

I had a large valve gas flowed head from TSR fitted recently, several other mods done at the same time, and I'm still running in, I've noticed an improvement in top end (above 4000) but suspect some loss of torque at lower revs......the power band has clearly moved up , so I'm fitting a VSR manifold to compensate.