unleaded heads?
Turbo Mini Forums

this is probably a stupid question but can someone give me an in depth run down on cylinder heads, do most of you have unleaded heads or do you have to keep using crappy four star, i understand you cannot use additives (redex) etc cos of the sodium valves or summat please explain. also why is it most of you dont go for larger bore engines 1380's etc most stick with a 1293 or similar, whats the best size bore and chamber size. bit puzzled hope sum1 can help :)

Modified head is what I run...

but Millers VSP is a very good product and I have used it on a std head before and in other engines for 1000s of miles!

Alex

AlexF

bore size, keep to a minimum

1293 is easiest +0.20"

chamber size to match dish and give correct compression ratio.

additives are fine with sodium valves. just use a good additive, i personally use Castrol valvemaster but a lot use VSP. Dont use cheap ones are any of thses inline things as they dont often work!!

its a safer bet to build a small cc but stronger engine then run more boost, than a big bore - with more flex in the block - at lower boost there will always be exceptions but this is the basic reason
sodium valves are fine with unleaded but the head is not , you can fit hardened valve seats but there is always a possibillity that they could come out if the engine is overheated - relaxing the casting an reducing thier tight fit -

i also use the castrol valvemaster, for the pure reason its the only one i can find in local shops!

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

valvenmaster worked in my camper van (1.6 air cooled) for thousands of miles without a problem!

alex

AlexF

cheers guys helped a lot, if i buy a modified head can i get anunleaded one?

yes you can Gav, aslong as you don't go for huge valves.
However, some head grinders don't like unleaded heads as the harderned seats can fall out.

Team Racing