i have played with a few of these now & we are really starting to make some "head-way" ,,, these are not really the best heads straight out of the box tho... pretty damn yukky actually, & if i were anyone contemplating fitting one of these heads i would seriously look at getting someone to actually fix them & work them a bit before fitting for sure

anywasys, pretty pics of some long hard tiring painfully slow work in progress

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

oh & yes Dave M , this is your head, not far off being ready for you

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Whats the playdough for??

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Tim
Dusk Blue
1964 850

Radius entry to the port. If you don't use it you will get a wrong (low) reading of what the port can really flow in practice.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Can we name the brand?

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100% Pure A Series Turbo
Morris - The Original RedBull Racing

I don't see why not, it's just a Pierce 7 port, innit.
Most aftermarket alloy heads need work to make them flow good or better, they are never perfect out of the box.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I know this is a bit off topic but why dose it seem 7 ports are preferred over 8 ports doesn't the siamese exhaust ports of 2 & 3 cause flow restrictions of some sort?
In my brain the effort of making a new four pipe exhaust manifold is worth it to get that little bit extra out of the engine...after all that's the whole idea of the head, better air flow.
Just something that bugs me that's all.

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Respect mine and I'll respect yours.

Yeah it`s all a bit of a fudge really,,, the play-doe is needed to make it "sort-of-real" but not quite,,, but if you use the same piece/shape of play-doe for all your testing then we can see any difference in what mods we do to the ports/seats etc & as the play-doe stays the same for all tests yeah?


& yes Pierce head , didn`t quite make 80cfm to start but came up just past 130 at the end , & i reckon we could do more but probly stuff a few heads trying , at least they should be pretty easy to weld back up again

& Kenno, i reckon there`s not much of a problem with the center exhaust really (just my opinion) there`s no real restriction there,,, & as much as every little thing adds up so yes maybe in theory separate ports could be better,,, however with the 7-port the firing order allows one center exhaust pulse to help scavange/extract the next.

GR would probably have more info on this topic than me, i`m just playing around die-grinding & testing

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

So matt what flow figures are you getting from the Twinkie 8 and 16 V heads?

I'm still toying with the idea of x flow on my 1310 turbo motor.........

Grant

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100% Pure A Series Turbo
Morris - The Original RedBull Racing

Ken Elder told me the other day the HP and torque potential of his 7 and 8 port alloy heads are the same.
He said he likes the 7 port because he doesn't need to supply bends & flanges to make a 4 port header up.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

The bit that baffles me about these heads is, everyone who's ever worked with one (of ANY of the ones available) says there's big gains to be had by sorting out the ports and/or chambers.

SO, given that you're only ever going to stick one of these on because you are interested in performance, why the hell aren't the designs/castings better to begin with? Surely there's some serious market share to be had by the first to step up with a head that's good straight out of the box?

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http://www.mini-hb.co.nz

IIRC 7-ports have been traditionally better flow-wise than the 8-ports offered because it's a bit messy to get the 4th exhaust port in there... pretty sure there's not much disadvantage with the shared middle exhaust port either with the firing order.

I think that's the answer.... I remember GR posting some pics of a sectioned eight port and the ports were quite serpentine.
I'll see if I can find the pics.
EDIT Found the pictures...As can be seen the center exhaust ports have dog legs in them.
Plenty of discussion in this thread.
http://118.127.22.78/~ausmini/forums/vi ... &start=135

we`re still finding gains,,, but truth is lately i havn`t had much time on the Twinky porting game, but i can tell you that i take some meat out here & there yeah,,, but i also add some meat in some places & have found gains too

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

I think the other issue with 8 ports is that to get any decent port size for the centre exhausts you really should change the order of the valves, so you can't use a standard camshaft

but that's beside the point - looks nice Matt

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did I tell you that I won a trophy?