65 replies to this topic

[mini13]

The Cinq head....

its an easy conversion because with the std cam the valves have less lift than the chamber depth, this also means that if the cam belt breaks then nothing is damaged.

the head flow pretty well despite the small ports and valves, in the Cinq it gives 53hp from 1108cc, that suggests it flows a similar amount as the 12g940.

there is also the Punto75 head, this is interchangable with the cinq head, but has a better port shape and hotter cam, these give 75hp on the 1250 punto block, hence punto 75...

fitting one to the mini is a challenge but easier than a lot of things, you will need to plug the stud holes and redrill and tap them, i think some of the water ways can stay but some will need plugging and redrilling, also a cam belt will need to be rigged up. and oil will need to be routed to and from the head.

although the head will not give a massive improvement over the 12g940, it will enable you to run proper EFI.

I think one of these heads with a turbo on would be excelent on a 998 though.

[Rosslin Racing]

Owens photos are not crossflow the ports are moved up

[Owen]

Owens photos are not crossflow the ports are moved up

Yep . Vizard briefly mentions this mod in the yellow bible and reports that he saw some of the best power figures he's ever seen out of an N/A motor (no actually power/torque figures mind).

[trafficface09]

hmm this is really fasinating stuff! i really need to get aq vizard bible. its off topic but i have been looking at gsxr pistons as i think they are quite a bit lighter and will give a nice high reving quality.

i now have to admit that i am extreamly tempted by one of the fiat heads with a eaton supercharger or maybe a turbo setup

[samsfern]

I'm interested to know how you plan on welding those plugs.

it is possible to weld cast iron, not easy though, the head needs to be heated up quite a bit before you weld it.

[mini13]

also the fiat 1.2 16v head can be made to fit, these flow much better than the 8v, but you'll need to think abput valve cutouts.b

hmm this is really fasinating stuff! i really need to get aq vizard bible. its off topic but i have been looking at gsxr pistons as i think they are quite a bit lighter and will give a nice high reving quality.

i now have to admit that i am extreamly tempted by one of the fiat heads with a eaton supercharger or maybe a turbo setup

the bike pistons are interesting, they will have a much shorter deck height, and therefore be more stable, but you'll either need to skim a shed load off the top of the block, or get some longer conrods

Edited by mini13, 14 June 2010 - 05:07 PM.

[mini-geek]

this is a serious case of if you have to ask, you wont be able to do it........

also it will probably be cheaper to buy an alloy 7port from the us, they where on ebayut i can't find them now

[AndrewJ530]

With postage and everything taken into account, i'd imagine it would be cheaper to get an MED 7 port than get one from the US.

Edited by AndrewJ530, 14 June 2010 - 06:01 PM.

[alexcrosse]

owens pictures show an old school ford trick used on many pre crossflow and crossflow heads to get lots of power from IDA carbs. Lovely mod, id love to see someone running one of these different!

[trafficface09]

hmm i wanted it to be a discusion not a can i do it thing, im not that bothered by cost, and id rather build a setup, it is posible and actually not very difficult if you break it down into steps. i have acssess to the tools and im fed up of being told i cant do it, if i didnt have the tools i would buy an 8 port.

thats fair isnt it?

[samsfern]

why not do a bmw k bike head? 16v and twincam, you can buy a template for adapting the block from specialist components. you can run twin 40's or throttle bodys and infection, and the head has 8 ports

Edited by samsernie, 14 June 2010 - 06:18 PM.

[Owen]

hmm i wanted it to be a discusion not a can i do it thing, im not that bothered by cost, and id rather build a setup, it is posible and actually not very difficult if you break it down into steps. i have acssess to the tools and im fed up of being told i cant do it, if i didnt have the tools i would buy an 8 port.

thats fair isnt it?

Prove everyone wrong then! I reckon go for it! Everyone does bolt on mods these days, I love home made mods.

I'm gonna give that downdraft mod a go when I have sorted out (cleared out) my other projects!

If you do do it, keep us updated! Good luck!

[mab01uk]

Yes why not just try something already proven to work like the BMW K twincam head and you will have your carbs at the front?
http://www.lojomo.com/

Quote:
"The first step in building yourself a twincam 'K' conversion is to source a cylinder head, this is not too difficult as there are many BMW bike breakers advertised on the internet, BUT with the success of this conversion many breakers have raised the price from £100 2 years ago to approx £350."
http://www.morspeed....guide page1.htm

m_sd7StOLnU

[trafficface09]

unfortunatly its an insurence thing. ha ha i mean i could sell the engine once its finished,

im looking for a setup thats 8v high reving but not to insane. thats why im looking at a custom crossflow

or fiat head

[samsfern]

there is an 8v bmw k bike head as well which again has 8 ports..... but it would rev better with 16 valves

Edited by samsernie, 14 June 2010 - 06:29 PM.