19 replies to this topic

[087dave]

Hi all, just wondering about minisport stage 3 998 head

it says on the website inlet 29mm exhaust 25.4(which is standard for a 998)
so how can this be anygood
even if you have a good cam and inlet and exhaust system

on the inlet side you are getting more fuel/air in but exhaust the same as standard

so is there any gain in fitting a head like this one

What do you guys thick????

Dave

[racingbob]

if i was you i would be getting a head from one of the race tuning places like slark or med
but keep eye on ebay theres been a few good heads to suit 998 been modified

[JustSteve]

Heard nothing but bad things about minisports heads... I'd deffinately stay away and contact somewhere like MED

[Shifty]

This chap always comes highly recommended and I don't think I've ever heard a bad word said about his heads.

http://www.turbo-mini.com/4598.html

[bmcecosse]

With valve sizes like that - it's a waste of time. Best head for a 998 is a 12G940 from a 1275 engine. On the 'Minisport' scale it would be a STAGE 10 compared to that head you describe !

[valve bounce]

standard 998 mini valve size is 26mm in and 25mm out, so yes there stage 3 does have bigger valves, but if it were me id be buying a 12g295 get it skimmed so the compression ratio is right and job done.

[087dave]

Thanks for the replys, so whats the gain with this head having bigger inlet and standard exhaust

[bmcecosse]

Actually 27 (26.9875)mm inlet and 25.4 mm exhaust..........on the standard head. The miniscule extra inlet valve size will make very little difference.........

Edited by bmcecosse, 24 June 2012 - 10:29 PM.

[087dave]

No man 29mm inlet 25 exhaust so is there any gain

[087dave]

Cherrs a waste of time so then.........

[bmcecosse]

940 head - it works!

[087dave]

<sub>would a 940 head fit a 998 block without been pocketed

if so how would you go about it

cherrs</sub>

[coopdog]

<sub>would a 940 head fit a 998 block without been pocketed

if so how would you go about it

cherrs</sub>

you cant,
if you dont want to do that get 12G295 head which was made for the 998 cooper, its much better than the standard head

[jakejakejake1]

Well the 940 can be fitted without pockets in some circumstances, but it requires sinking the valves into the head, and also depends on what cam/ rockers you are using as well.

[Artful Dodger]

The best way to fit a 12g940 head on a 998 is by recessing the valves into the head. This works by letting the valves further into the head, and then spacing the rockers. It's best because you don't put a divet into the block.

Edited by Artful Dodger, 30 July 2012 - 09:28 AM.