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16v head pictastic

2K views 51 replies 16 participants last post by  Topbuzz 
#1 ·
this is a quality ported head!!:D :D




 
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4
#4 · (Edited)
Its a turbo head so dave went the conservative route, but it helped me gain about 30 odd bhp inc cams at a calibra rolling road day.

Other than head and cams, and decat the car is std running std chips and .8 bar boost. I think port enlargement was 2mm on inlet and 1.5 on exhaust, but it has helped no ends especially the torque through the rev range.

Also having looked on daves website it looks like he's gone into business, i`d recommemnd him to anyone for head work.
 
#6 ·
hehe... I was gonna ask is it was DVA.

Having visited him a few times, all his stuff comes out like that, and he's helped me loads with what I've done in the past.

It's very rare to find someone in the tuning world as open, honest and selfless as Dave.

:beer: :beer:
 
#10 ·
Where the single port on the inlet side of the head divides into two, to go to each inlet valve.

pictured in the third picture up there.

To Knife Edge it, well, a knife is something you stab somebody with. i.e. it's sharp. So instead of the rather thick split. You thin it out, and the start of it is like a knife!

From:


.__
/..\

to

./\
/..\



sorry about the .'s but the message poster takes out consecutive spaces...
 
#13 ·
heheheeh.. no Brian, your explain is so easy to understand..

Well, my opinion about the knife, i think is two.. Because if you make the knife, you will improve power in high revs, because will have less restric for flow, but in low, you don't will have turbulence, and badder emulsification mixture(when the gas mixture with oxigen), but if you keep route, in high revs you will lost power, but get better power in low and mids, and better fuel economy. I will make a knife in my 16V head.. heheeheh..
 
#15 ·
An Airplane wing has to do a different task compared to the inlet port though.

Knifing the edge of the siamese port...




sorry, but I don't beleive the left diagram presents less of a restriction to air flow than the one on the right!!

Excuse my shite diagrams by the way! lmao
 
#17 ·
The trumpet is operating differently, as air is not approaching it from one direction. As tghe low pressure is created by the inlet valve, air is drawn in through the inlet. At the trumpet entrance, air rushes from everywhere surrounding the trumpet exit. This is where you need a smooth run for all the air. Once in the port, it's uni directional. so all the air is heading directly towards the split.

This makes it different to the trumpet entrance where air is being drawn from all angles.

ah well. Best not do any more headwork until my head modding books arrive lol!

Thanks.
 
#19 ·
WHAT IS MEANT BY THE TEARM PORTED, DOES IT BASICALLY JUST MEAN CLEANING THE INLET AND OUTLETS FROM THE VALVES TO COMBUSTION CHAMBER ETC... I THOUGHT PORTING MEANT TO CREATE A HOLE TO INCREASE THE AMOUT OF AIR FUEL / RATIO.. CORRECT ME THO PLS I MAY BE CHATING SHITE...:D I AM SO GOD DAMN KEEN TO LEARN,,,,

MY QUEST FOR KNOWLEDGE CONTINUES
 
#20 ·
well..

it´s your head´s
and if you don´t wab´t to max it out then don´t listen to me..

but here´s a piccie to maybe convince you..
hem.passagen.se/hitmeharder/pics/topp/Image-02.JPG

As you can se the edges are round and smooth at the 'bulges' that the valve stems are going in..
BUT!!
at the 'backside' of the 'bulges' the edges are knife edged.

This Head is a CNC-Ported Nascar chevy smallblock.
and they got about ~750hp with only one carb.

this should be proof enough,,

Cheers.
 
#21 ·
InsaneSwede said:
This Head is a CNC-Ported Nascar chevy smallblock.
and they got about ~750hp with only one carb.
Cheers.


Looks nice. "with only one carb" that will be one very big four barrel carb; ie the same as 4 single ones.

A "small block" is that 7000cc?

100 bhp per 1000cc is "normal" for a tuned NA engine, so I'm not so inpressed by the 750 bhp.
 
#23 ·
to fill up with info..

a guy here in sweden built an nascar spec engine but with more free flowing carbs (two 830cfm)
and that engine pulled ~840hp at 8600rpm

still 5.7 litres..

that´s impressive my friends.

840/5.7=147.4hp per litre..

that´s kind of the same powerlevel as an 4 valve technology BTCC racer (late -90´s)

so do you guys think they know some things about airflow or what?
 
#26 ·
hmm iirc i'm sure i've heard something about 2v per cylinder being different due to layout etc that they shouldn't be knife edged as it obstructs flow

could be wrong tho i'm reaching far back into my memory bank here
 
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