7 port head
Turbo Mini Forums

Hello all, from down under. Have recently been bitten by the mini bug as a friend of mine wanted to make his old mini 1100 go faster than its normal snail pace. I know nothing about A series engines & have enjoyed reading various articles in this informative forum. Have come from a turbo rotary background & offered to apply my knowledge to his long term project. The first stumbling block I noticed was the poxy Siamese inlet ports! Have enlarge these to the point where I entered the push rod hole area & have had some sleeves pressed in with the minimum possible id. to allow as large as possible port. Then made a divider plate so I will end up with 4 X "D" shaped inlet tracks. All be it not enough flow for a normally aspirated hi hp. application, add a turbo & let the flow begin! I now have 4 separate inlet ports, will use 4 injectors & can easily & efficiently control fuel delivery using any number of aftermarket efi systems. We are using the 1100 because it's what we have got .If any body is interested I will post progress reports & pics as we go. Regards Russell

get some pics up

iain, will be 3-4 weeks before the head will be photogenic (as this is is a part time project) & hopefully the inlet manifold will have progressed enough for pic's by that time as well.

sounds cool,

A company called Manx racing did something similar i believe.

I have considered doing the same thing. On a 998 or 1100 turbo I reckon you can get the ports big enough this way. Not sure if they would be large enough on a 1275+ though. I will be interested to see how it looks, I am still at the planning stage.

Ben

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

good good, i look forward to seeing the pictures

in miniworld a few years ago there was a pickup with the manx 7 port head on, this was a 1293 with it and popping out 140bhp

Which was owned by Bank Garages. The owner of BG is a complete tosser and lies about everything...

yeah i reckon the MG range are now fantastic value for money.

saw a MG ZR 160 at a dealers this week with 14k on theclock and superb nick, only £3.5k!! 03 plate as well!

Hmm, Its a damn shame that there's so many tosser's out there that talk complete BS, I bumped into a guy in my local recently who was asking about my min...

"what lump ya got in there?" he asks,
"Oh, 1380 rally cam ect" I say,
"mine's got a metro turbo lump that puts out 230bhp!"
"oh really, say I what intercooler do you run?"
"nah, don't need an intercooler"
"right.... what gearbox do you run?"
"Oh Its got an Austin Pricess Box mate"

Eccetera....

Now, I realize that I am not an expert and a lot of stuff is possible with time and effort, but i refuse to belive that someone that looks and sounds like the have mental problems has got a 230 bhp mini with a princess gearbox....

But anyway, While messing with the inlet ports how about downdrafting them too? Des Hamills how to tune A series engines has a bit about Slark downdraft heads in it. Also for the amount it would cost It might be an idea to pick up a 1300 head and mod that instead to get a bit more flow.

mini 13 There are as you call them "tossers" out there. In Aus we call them "wankers" I can assure you this head is happening & as I stated I know nothing about A series engines but feel sure with my 38 yrs experence as a mechanic ( yes I'm old ) & the last 20 yrs in the modified car scene, I can make this old mini fly.I've been actively envolved in the turbo rotary industry for the last 12yrs. & thought I could apply my turbo knowledge to my mates mini. If the head works I'm more than happy to post my findings as the mini scene in Aus is very small & not many are interested in my ideas. be patiant the pic's will come. Russdog

russdog
by all means buddy give this ago but........ IMHO

its a dead fish!

its been done before MANY times with difficulties getting the distribution flow right

you would get better flow results and more power from a well thought out 5 porter
with less hastle i can assure you !

may be the minisport 7 port head is going in the right direction but while they were at this, they forgot the 4th exaust port

iam flabergasted !????

having said that.....
this head togeter with fuel injection and mapped ignition would as Turbo Dave said make a killer engine. and i agree with him come to think of this

http://www.minisport.com/mini-sport/engine...inder-head.html

BUT..... the desing guy must have been totall pissed !

or thinking on the wrong train of thought!
not adding that extra exaust port with a brand new casting desing

good luck,
but................. a feel that this will come back to bite you!

Ben:

Ben, it isn't a brand new casting design. The head has been sold in Denmark for over 20 years.

http://www.akmracing.dk/

Minisport have just bought the castings and manufacturing rights.

Also, the main thing about this head is that you may use a standard camshaft and exhaust. This saves some money.

If they'd made another 8 port, the head must have been better or way cheaper than the Elder or Arden items. I don't think this is possible with only two valves.

The exhaust pulses on the centre exit port are 360 degrees apart, so that will not reduce power I guess.

With a turbo, the 7port is great, as you may use the standard manifold though.

I agree though, I would never have bought a 7 port as the two outer inlet ports are ridiculously angled, and two exhaust valves are still in the middle together creating heat.

Edited by Vegard on 16th Jul, 2005.

intresting link vegard,
great reading from Mr VIZARD.

my oppinion has changed slightley in favour
a little on the 7 porter

but there over priced too much!

having said that vegard
my reply was geard to russdogs approach to port splitters in the 5 port head
IMHO its not worth the hastle

but i suppose if you have the time..................

i hate to rain on his parade..

i wish him GOOD LUCK!

Russdog, my anecdote on tossers was in no way meant to be derrogetory to you, On the contary any one that works on rotary engines has my respect (I still consider them witchcraft)

Also concerning the minisport 7 port (I have one on order) Yes it is a compromised design in comparison to an arden or westlake, but it does work out a lot cheaper, As Vegard says you can use a std cam and exhaust, But also with an arden over the 7 port you'll need:

Inlet manifolds, longer pushrods, Special valves (if you want to go bigger than the supplied S sizes), longer head studs, Also you'll need to get the combustion chamber cut.

In addition to this I have heard that due to the cam you'll need to run S rods as a std 1300 bottom end will hit some of the cam lobes, (this may or may not be true, But allegedly Bill Richards says its so)

i called mine the 'split port ' it was a flow bench test 'mock up' with alloy plate epoxied in place 9/16 in offset pushrod tubes , using a 36 mm inlet airspeed was around 3.5 times higher velocity, but just couldn't get enough flow to make it atmo usable - as i recollect 69 cfm @10in h2o on a superflow 110 with 1/2 lift (standard 36 mm head flows 63 cfm, race 36 head 93cfm both at 500 thou VL, conclusion was it would make a good atmo engine for towing ! but with forced induction puts a different spin on things , maybe use a more balanced inlet to ex ratio on the cam to make up for reduced flow , ie 276 or 286 ?

Stuart, I think this is what you are saying:

Standard head flows 63cfm

Race head flows 93cfm

'split' 7-port head flows 69cfm.

If this is right, then it would seem to be the ideal head for my use. I say this, as at the moment we have 140banans using a totally standard (port wise) 12G940.

The split head would flow slighty better than this and allow us to run injection.

Do you still have this head knocking around?

Wil

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

i dont ! , it was a flow bench trial ,still got the program in my mind ! but yes it would work even better with smaller cc's ,the inlet port was large and sqaure untill the divider went in making two rectangular ports, not sure how long epoxy would last , maybe something a bit more nasa spec is available now ? would work perfectly with injection manifold will take some fine fabrication to get get right , mirage mentioned some specialist grp stuff to make inlet manifolds maybe thats the way ?

Having a bit of experience with fluid flow (and gases) I reckon from what I've done with heat exchangers the same principles apply. I reckon that the split port idea stinks. Sure you'll get rid of the charge robbing but the resistance of the tube is considerably higher. I think of it like this, image that the walls of the port are sticky (they are to air) the air is also sticky against air and moreso when you pressurise it, so, ideally if you imagine having a section of the port (circular) the gas in the centre will be at a higher speed than that at the edges, obviously this ideal circle distorts if you're trying to make it turn corners (imagine bending a piece of pipe lagging). So, the further you distort the shape from the ideal circle, the more the resistance goes up. If you ask me those split ports look pretty antisocial to gas flow. Particularly for a big engine running a lot of gas. As you guys keep telling me, theory is one thing and practice is what counts, I would be very surprised if the flow on a flowmeter was not a lot less. Who knows whether the benefits would beat the limitations.......I doubt it. I reckon that downdraft 5 port looked like a good idea.

As far as the 7 port head went, I had a look at some of the cores for the thing and it's beautiful. What struck me as a bit queer was the different lengths of the inlet ports. Apart from running injection, if you were after any shockwave inlet effects, bearing in mind these are more significant with boost, the resonant frequencies could be spread around quite a bit, not that anyone is that bothered about inlet resonance anymore, they still go to tremendous efforts on modern cars. I can't recall the actual difference in length, maybe it is unavoidable with the xooxxoox configuration and similar on the Elder head. I would pay a bit extra and go for a Weslake if I could find it.

If anyone wants a photo of the AKM cores, give me a shout and I'll bung them down the line.

Stu (more theory bollocks, just when you thought I had buggered off!!)

Bugger off, I'm getting there.

stu, post the pics of the cores, or email them to me and I'll post them

Team Racing

Done it.

Bugger off, I'm getting there.

I'll them posted asap

Team Racing

I was looking at a pic of an elder 8 port about 10 mins ago and somthing clicked, as its xooxxoox cnfig as stu puts it, what must the exhaust ports look like!!

Jimster i'll mail you the pic if you could please post it so everyone can see what I mean.

will post all pics in a bit

Team Racing

This one ??

http://www.minicooper.org/images/un_pub/unpubl2.gif

Metro turbo weekend driver,Mini turbo in the making again!