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Round or Square
https://www.ausmini.com/forums/viewtopic.php?f=5&t=5222		 Page 1 of 2
Author:  gafmo [ Wed Mar 02, 2005 3:28 pm ]
Post subject:  Round or Square
just read this in Miniinfinty Forum and thought I'd Share it with you all From MORSPEED

I wouldnt call myself respectable shabs!

Square ports allow more flow and less swirl, (this is why we make the inlets square!) This is proven on the flow bench & dyno, But what is also shown is the mini exhaust ports flow too much in standard form so they do not really need touching, Again this has been tested by using STD exhaust ports, Enlarged ports, round ports and 'D' shaped ports.

STD ex ports worked well on a road & race car.
Enlarged ports made very little difference even on a full race car.
Round ports LOST power, So we had a round LCB made to match, This still did not work.
'D' shape ports are just a gimmick ive never seen a noticable difference.

All the heads i do for Pete Vickers miglias cars are 'D' shaped on the exhausts, But only because thats what he tells me to do!
In reality the exhaust ports on a race head are only so big to justify the cost, I dont think you would be too happy if you spent £1000 on a full race head that had STD exhaust ports!!!!

Now inlet shapes! again ive done many tests, Square, Round, even tear drop shapes. and nothing gets near the power that a square inlet port produces,

But to confuse things even further its where the material is left IN the head that matters not how much you can remove or how big you can get the ports.
All the power comes from the valve size and throat area known as the long and short turn.

Belive me ive spent 13 years flow testing and dyno testing heads/engines, Im just over my 1000th head ive modified.
I modify heads for so many other companys if you didnt buy the head from me direct, Theres a good chance it started life from me.
Author:  nuclear_mini [ Wed Mar 02, 2005 4:36 pm ]
Post subject: 
damn aye... i wonder how his heads would go against GR's???

but from the sound of it, I would love to get one of his for bricktop in turbo form!
Author:  kazjim [ Wed Mar 02, 2005 5:08 pm ]
Post subject: 
So, is there enough meat in a 12G202 inlet port to make them square ?
mine are currently round.. (about 1" diameter too !)

Later
J
Author:  drmini in aust [ Wed Mar 02, 2005 6:52 pm ]
Post subject: 
kazjim wrote:
So, is there enough meat in a 12G202 inlet port to make them square ?
mine are currently round.. (about 1" diameter too !)

Later
J


202 has square ports already. :lol:

BTW GR drills the exhausts round on his race heads, I don't think anybody in Oz has get more power yet from a NA 5 porter than he has.
Well over 150HP at crank, from a 1300. :wink:

<edit> Gafmo, if those dudes you quote were right we would all be running square exhaust pipes in our LCBs.. :P
Author:  CLUBMAN [ Wed Mar 02, 2005 7:11 pm ]
Post subject: 
wouldnt mind one of these GR heads,any clues on price?
as iv been told that all the power is in the head :lol: not the mind,i mean motor
Author:  EST-071 [ Wed Mar 02, 2005 7:14 pm ]
Post subject: 
drmini in aust wrote:
kazjim wrote:
So, is there enough meat in a 12G202 inlet port to make them square ?
mine are currently round.. (about 1" diameter too !)

Later
J


202 has square ports already. :lol:




I have got a 202 and it has square exhaust and round inlet ports!!!
Pete
Author:  kazjim [ Wed Mar 02, 2005 7:31 pm ]
Post subject: 
Pretty sure mine is round too ......
I know i have one on the shelf with square ports, but the one on the car is almost definitely round.. (998 Cooper ? - Graham?)

J
Author:  CLUBMAN [ Wed Mar 02, 2005 9:45 pm ]
Post subject: 
yes,the inlet starts round,put put your finger inside,it goes to a square :wink: when ya port them out,the idear is to make it round all the way in isnt it?
Image
thats a photo of a crusty old 202 head[/img]
Author:  drmini in aust [ Wed Mar 02, 2005 9:50 pm ]
Post subject: 
12A1456 (& the 998 Clubbie smog head- CAM4180) is round, all the others are cast square. ie 202, 206, 295, 940, 1316.
Between pushrod holes & further in, that is- they are all `round' right at the manifold face. :wink:


Clubman, no- the inlets are better square, better cross section- it's the exhausts that are sometimes drilled out.
Just make the inlets bigger and smoother. FFS use Vizard's books though or you might stuff it up!

<edit> p/no of smoggy head added.
Author:  CLUBMAN [ Wed Mar 02, 2005 9:54 pm ]
Post subject: 
i havnt realy started,i just pissed off the beat,as was told that now the inlet will get sucked out the exhaust,and hopefully give me some flames :lol:
Author:  ausminis4u [ Thu Mar 03, 2005 9:18 am ]
Post subject: 
i thought this was going to be another clubby vs morris thread..... lol
Author:  CLUBMAN [ Thu Mar 03, 2005 1:20 pm ]
Post subject: 
clubman is morris :wink:
i was about ready to fire up to :lol:
Author:  gafmo [ Thu Mar 03, 2005 5:02 pm ]
Post subject: 
Round or Square... :lol: I knew it would get a few people..You should know me better than that..

Kev by the sounds of it this guy has been Flow testing heads for 13 years of experiance..
This is why I post it :shock: Special as Mike inlet and exhaust are so large
Author:  drmini in aust [ Thu Mar 03, 2005 6:42 pm ]
Post subject: 
gafmo wrote:
Round or Square... :lol: I knew it would get a few people..You should know me better than that..

Kev by the sounds of it this guy has been Flow testing heads for 13 years of experiance..
This is why I post it :shock: Special as Mike inlet and exhaust are so large

If Mike has any $$$ left, take his motor & box down to GR and we'll throw it on the engine dyno, see wot it's got. :P

I'll probably run the the new 1360 on there in a few weeks. :wink:
Author:  CLUBMAN [ Thu Mar 03, 2005 7:13 pm ]
Post subject: 
is it using the same block at the 1310 special?
what is being done while its apart?
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