M20 oversize valves

Wed Sep 11, 2013 11:59 am

Where would one purchase a set of these? What options are available to strokers? I believe Alpina used the +1mm valves (maybe only exhaust side?) - but I would love to get other opinions here. I know that IE does them - but anyone in the UK?

Wed Sep 11, 2013 7:00 pm

I have spoken to a UK company about these valves they do list them but had run out of the blanks, they should be back in stock now.

They are +1.5mm over standard. The research done by Hairyscreech and myself would suggest the inlets are where the bigger valve is needed. It puts the ex/in size ratio to a better value, and is more suited to the size of the inlet port.

I will be ordering some myself soon, I'll contact the company and let you know, their name escapes me at the minute, but I have saved the emails.

Watch this space.

Thu Sep 12, 2013 11:54 am

Nice one - keep me posted!

Thu Sep 12, 2013 9:32 pm

GS valves butt.
Well that or REC (Race Engine Components) same difference.

Mon Sep 16, 2013 2:13 pm

anything bigger than 43mm needs biger seats installed

there are a few ford engines with 7mm stem valves that are much longer and bigger then needed, sometimes nice stainless ones can be had for about $15 each, then if you can find a race shop who does custon valve work its not a big job to have heads turned down to what ever size you need and cut to length with new keeper grooves and hard tips but on, usually works out cheaper than full custom valves etc.

if your going this rout then go straight for 44mm intakes they pay off well when it comes to head flow, leave the std 36mm exh valves but they benefit from some nice porting.

Tue Sep 17, 2013 3:02 am

Already looked into this, one of the ford v6 engines uses a pretty much dead on valve at about 45mm, however the tweeking needed once you factor in ripoff Britain is not worth it, the GS valves come to about £150 and the modified ford ones are £100 plus another 2.5 hours min @ £60 per hour if they would even entertain the job.

Its something that would be viable in the us or oz but there is sod all here engine shop wise and those that can do it are not interested in doing it.
The uk sucks for this kind of thing.