paulf
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| posted on 10/3/07 at 11:04 PM |
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zetec inlet port matching to manifold.
Im presently trying to make a manifold to fit throttle bodys to my Zetec and am finding it hard to match the round pipes to the port shape. I could
squash them and then try and match the shape after welding but have been trying to keep the pipes as round as possible.
I have made a plate and put one inlet pipe through at an angle, but this means that there is a large step at the bottom of the inlet port, I would
like to grind the port top match to the manifold as it then means I dont have the miss matched section at the top where the original injector
clearance was.
I have attached a picture to show what I mean the area is the lump enclosed by the blue marker pen line, does this look ok to do or a bad idea? im
assuming that there is no water ways in the area just below the port at the manifold face.
Paul..jpg)
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TangoMan
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| posted on 10/3/07 at 11:14 PM |
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I wouldn't. You will end up with fuel puddling there as the cross section will be much larger so the air will slow down. You may also find a
waterway!!
I have used ally tube squashed to an oval at the head and then ground to match the ports after welding to the flange.
I have ignored the injector cutout as a step in the right direction will not hurt. It will actually be a benefit with wilder cams as it will hurt the
reverse flow with big valve overlaps.
Summer's here!!!!
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nitram38
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| posted on 11/3/07 at 04:38 AM |
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quote: Originally posted by TangoMan
I wouldn't. You will end up with fuel puddling there as the cross section will be much larger so the air will slow down. You may also find a
waterway!!
I have used ally tube squashed to an oval at the head and then ground to match the ports after welding to the flange.
I have ignored the injector cutout as a step in the right direction will not hurt. It will actually be a benefit with wilder cams as it will hurt the
reverse flow with big valve overlaps.
You might also leave a fuel puddle if you don't remove it, in the inlet manifold!
Porting any head is a risky thing because you can get unexpected results.
For instance on the hillman imp exhaust port, if you fit a tubular exhaust manifold, it is ok to match the port to the round exhaust, but leave the
gasket as standard.
In other words the gasket being smaller dia, causes a reflective exhaust pulse back into the head. This actually helps increase exhaust velocity and
improve horse power!
It is best to look at some tuning books for your engine and make some decisions from there.
What you are thinking of trying has probably already been done.
My advice is to shape the inlet manifold to the port as already advised.
[Edited on 11/3/2007 by nitram38]
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