tribetype40 0 Posted July 31, 2007 I would like to hear from anyone whos done extensive top end tuning to weigh up the effectiveness of the mods. Considering a big valve head, ported polished etc and some cams. There seem to be a few different profiles available so good to hear from people who have or have tried different set ups. cheers, Doug Quote Share this post Link to post Share on other sites
junkie 0 Posted July 31, 2007 What engine are you doing? Quote Share this post Link to post Share on other sites
tribetype40 0 Posted August 1, 2007 GOOD POINT! VR6 Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted August 1, 2007 I have a VR6 head with 1mm oversize valves, with the exhaust valves being made of inconel. Heavy duty springs, titanium retainers, 3 angle valve cut, port matched intake etc etc. If your engine is naturally aspirated and of the stock capacity, I wouldn't bother personally. It's only really worth doing on the VR6 when bore size is 83mm or larger and / or turbocharged. I haven't fitted it yet, but I've been told by the machinist that both power and torque will increase uniformly. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted August 1, 2007 Is that from CNC heads Kev? have they released the figures yet? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted August 1, 2007 Errr....no! Ask Yan, they don't bother responding to queries....but they seem to find the time to get their advert into lots of car mags though :roll: And at £1250+VAT with standard valves, they can keep it. With extrac capacity and/or turbos, it's all about cylinder filling and gasflowing is of no help. Bigger valves are more important than shiney port walls. Quote Share this post Link to post Share on other sites
Yandards 0 Posted August 1, 2007 Errr....no! Ask Yan, they don't bother responding to queries....but they seem to find the time to get their advert into lots of car mags though :roll: And at £1250+VAT with standard valves, they can keep it. With extrac capacity and/or turbos, it's all about cylinder filling and gasflowing is of no help. Bigger valves are more important than shiney port walls. Still waiting on a reply to an e-mail, tried two different e-mail accounts too just to check their spam filter wasnt causing an issue. Might have to resort to a phone call instead.. You got any flowbench figures for your new head Kev? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted August 1, 2007 I haven't, I'll ask Bill for them..... Any idea what the standard VR head is in terms of CFM, for reference? Quote Share this post Link to post Share on other sites
Yandards 0 Posted August 1, 2007 I haven't, I'll ask Bill for them..... Any idea what the standard VR head is in terms of CFM, for reference? Nope I don't but the guy that did your head (Bill?) should have before and after ones hopefully. Quote Share this post Link to post Share on other sites