So Pierce, Specialist Components or Ken Elder? Do you pay for the right one first or get the cheap one and fix it?

I think I need to do this. The cost of the head will probably be insignificant compared to the cost of the broken drivetrain bits though...

When you reckon you've got it sorted Matt, you can do mine.

There isn't really much benefit to these.
Alloy is better for cooling and avoiding hot-spots so you can run higher compression.
Four inlets lets you put decent injection on it so your turbo/supercharged set up can be much better tuned that a suck-through or blow through set up.
It looks cool.

Sure they have ports that are too big at the flange and have poor angles just above the valve seats, they aren't always flat and the space for the valve springs is too short... but I like them anyway.

M

My Pierce 7port has been running flawlessly since Jan 2011.


Done 4-5 track days and many Kms in between. Daily drive ATM too.


Pretty happy with it.

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Now with 2 extra ports!

SuperCooper,,, glad you havn`t had any dramas with yours mate, that`s cool
i know a few other guys running these heads with no real trouble too -->& not saying that theyre rubbish at all ... just that they certainly are not the best head "out of the box"... as-in they can do with some "tickling" before fitting, especially if you were after better performance.

if you wanted to check out their "issues" then definately look at the springs, seats, & short radius in the inlet & exhaust ports (at least)... & to make sure it`s actually flat ,,, all the heads that we have seen have all had similar issues in all those depts.

as Mokestar said,,, they have some things need fixing

but still,,, we shall see the fruit from what we have done once this head is fitted & running & we have others waiting in line for similar treatment.

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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.

Link to my thread back then:

http://www.ausmini.com/forums/viewtopic ... &start=150

Dug up some things we found when sorting out my head;

"I emailed MED in UK about machining under the spring seat and they advised against it on this head. Everything done to this head is a compromise because not many people have worked on them or modified them. I had the head flow benched before and after porting with good results without breaking into water or oil chambers.
The supllied dbl vlv springs are not real flash and coil bind needs to be checked with your cam and rocker choice.

In relation to sinking the valves , we did this so a quality dbl valve spring could be used and my roller rockers. Spent enough already. Ultimately , after sinking the valves , you would then grind chamber to suit then skim head for desired CR. " end quote.

"OK so the valve springs supplied with this head will not work with 1.5rr.
With my 266 cam the valve springs will bind at 1.4rr at a pressure of 200lbs. Even worse with 1.5 r.rockers
Tried some CAEA 526 spings and the installed height is only 1.26, not 1.42 which is recommended. The seat pressure is ok but the nose pressure is over 250lbs.
Emailed MED and they recomended not to machine out under the valve spring. They modify these heads, though they said thier castings from Pierce are different.
So off to see the guy doing the work for me tommorrow with some standard Cooper S dbd Vlv spring to see how they measure up for use with 1.5 rr. Otherwise his recomendation is to machine about 1mm from the valve seat to get the valve up higher to alter the spring pressure then try the CAEA 526 springs. " end quote

Matt I'm sure you've played with these areas on the heads you've done. Pretty happy how it goes for the price and ease of install.

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Now with 2 extra ports!

Do you have a velocity profile and a point where the port goes turbulent or backs up? 80 - 130 cfm is a massive gain. I'm assuming that you've been able to make it flow at higher lift, rather than finding 60 odd percent at the same point?

no we havn`t been able to make it flow 130plus at 200thou valve lift,,, or even 250thou valve lift,,,sorry,,, i`m not that good

you should be able to see the gains from this chart where it all happens, & most of it is above 300thou ,,, & just as the caps start smashing the top of the guides at 500thou



we have the use of a really cute air-speed probe so we can play around with adding metal & subtracting metal in different areas of the ports to see where we can gain & where it all falls apart...so (to me) it`s basically one of the best tools ever it overlays the high/low & medium air speed areas onto a pretty 3D picture of the port for me

This info is all then all plotted against the cam profile you punch in , also all your info like valve sizes & engine capacity & such (Massive amount of info the computer demands) & you get a rough guide as to what it will be able to produce,,, & strangely enough (with most of the V8 engines anyways) it hits the nail on the head spot-on. (most times)

we are still toying/practicing with designs/data for the mini heads, 5,7port & twinkys so we are no experts as yet but it`s fun & we are making chunks of ground compared to the way i used to do things

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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.

Sounds like fun. May I ask what software you are talking about? I'm really just starting to dabble in this sort of thing, more with my V8 affliction than mini, but the 7 port and the twinky appeal to me greatly because I am far more comfortable with a laptop and data graphs than I am with needles, seats, venturi and boosters.