strange forced induction head
Turbo Mini Forums

not mine!

maybe round is the new performance mod - round chambers, round exhaust ports....

http://www.ebay.co.uk/itm/Mini-metro-Turbo...=item5d4147f20e

WTF! round is not the way to go IMO LMAO!

maybe if anyone fits that their engine Bhp figures fuel economy would be round .............. the bend

Heads you win, head a few years old now from Geordie land.

I saw that 1. Whoever did it was a bit of a tool, you match the ports to the manifold gasket on the head and manifold. To y nowledge nobody makes a manifold using round flanges unless someone had made their own

wolfie...... this guy needs to see
a Psychiatrist .......... as tom says its old geordie land hat

Quite a lot of minis made a lot of power back in the day using fully scooped round chambers.
I can personally confirm that the engine still starts, drives, makes boost, and wins races with chambers like this.
Optimal, definitely not, but certainly better than a stock head...

The legendary BIR1 had a head like that albeit with square ex. ports. 14.2 if I remember correctly 10 years ago.
MED also had a line of heads with round ex. ports. Special manifolding required.

I'd barely touch a head with a mildly modified chamber let alone one with a completely butchered chamber !

Definitely a strange one for sure. Wonder what CR it actually ended up with ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Well the compression is certainly lower and the shrouding too.
does not look particularly well done on these pics but that does not say much.

looks a bit like an upside down ford kent 1600 ''chamber'' this way. those with the piston with a chamber and the head fully flat

matching anything to any gasket implies that there was actually a airflow/ thermodynamic thought behind the diameter of the hole in the gasket.



Nothing wrong with round ports. All things being equal ( and properly dimensioned) a round port is generally to be preferred. I just wonder how thin the walls are .. and how hot the coolant gets there.

Edited by Sir Yun on 13th Jul, 2013.

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

14.2 is good now let alone then

If round it no good, has anyone tried a square exhaust?

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Eh?

I've a head in the workshop modified by one of the respected names circa 1997 with chambers just like that.

I bet it works a hell of a lot better than a standard 12G940 - and, at the moment, its going cheap (not cheep, cheep, but cheap)

Joe, I mean that the ports are square on a mini head, in this post is it was that round ports are no good. I wondered if anyone had tried a square profile exhaust?

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

oh I see,

Noone has said that round ex. ports are bad....

I guess they can only then be the same or better?

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

round is better, you get stagnation in the corners of a square tube,

It's easy to sit here now in the internet age where there is loads of info and pictures out there and criticise, but this head was done by heads you win, either mark Haswell or one of his mates, and was on a turbo mini doing the business when some folk on here were still in nappies. Yes things have now moved on but if it wasn't for folk back then trying things to see what worked, we would most likely not be where we are now. Show a bit if respect!

Can you prove/ show us round is better than square Joe,

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

no offence intended, just some questions.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

jsut work out the "hydraulic diameter"

I was running square inlets and square exhaust ports with matched manifolds and gaskets all located by dowels with 1.5 to 2mm jacket thickness my major concern was boundary layer loss and total flow path volume. The performance difference was night and day across the board!

Own the day

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will