Streetwerks
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Streetwerks
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That's the ports scribed to match the gasket, quite a discrepancy As You can see
Streetwerks
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No it's for a high revving na engine. We have seen gains on this engine of over 12hp at the wheels. Not bad for a 1800 4 pot that puts out 190bhp in stock form
Streetwerks
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Stay off car forums, too many keyboard warriors who dont know **** about ****!!
Streetwerks
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That is the ports on the plenum that meets the runners, the manifold is a 2 piece where the runners bolt up to the plenum
Playing with manifolds and porting is fun 
........here's my one and only attempt at port matching. For my headwork, I ended up making the inlet ports smaller to flow more air using jb weld here a filled port on the head and a completed one
and turned 4 ptfe cores and cast the jb weld around them (and later smoothed them to the inlet ports)
the ports on the inlet manifold were also built up with jb weld (and a ptfe core was used in place of the injectors)
and the ports in the inlet manifold were filled and roughed out and checked against a steel core in the inlet port in the head for clearance (I though ptfe was too soft for this).
and when the ports were slightly oversize, a ptfe core in the head and the inside of the port in the inlet manifold were coated with jb weld and the inlet manifold was assembled to head to cast the weld to get a perfect port match.
the ports on the inlet manifold were then ported as normal
I too ended up cutting the inlet manifold up
and ended up reshaping the plenum
and about 8 or 9 years later its still going strong
........here's my one and only attempt at port matching. For my headwork, I ended up making the inlet ports smaller to flow more air using jb weld here a filled port on the head and a completed one
and turned 4 ptfe cores and cast the jb weld around them (and later smoothed them to the inlet ports)
the ports on the inlet manifold were also built up with jb weld (and a ptfe core was used in place of the injectors)
and the ports in the inlet manifold were filled and roughed out and checked against a steel core in the inlet port in the head for clearance (I though ptfe was too soft for this).
and when the ports were slightly oversize, a ptfe core in the head and the inside of the port in the inlet manifold were coated with jb weld and the inlet manifold was assembled to head to cast the weld to get a perfect port match.
the ports on the inlet manifold were then ported as normal
I too ended up cutting the inlet manifold up
and ended up reshaping the plenum
and about 8 or 9 years later its still going strong
Streetwerks
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its a mk2f polo 3f engine. I drive fairly slowly so I wasn't bothered about high end rpm, and with this engine there are two inlet manifolds that can be used. as standard the the engine comes with the larger manifold and the smaller inlet would only cost 1 or 2bhp. (standard bhp is 75 bhp) shown below are the inlet ports of the manifolds and heads for comparison. they were cast using alginate, which is the stuff dentists use to take cast of teeth as its cheaper that silicone and didnt need to keep the casting. my inlet manifold ended up being nearer to the standard sized one.
and here is a early version of my smaller inlet port compared to a standard inlet port
with stardard mods on the engine (air filter, chip, exhaust) these engines normally have between 85 and 90 bhp (at the fly). with the headwork and modified inlet manifold I have 98bhp (at the fly) if I ever get the engine set up on a rolling road, I should be able to break the 100bhp barrier. my engine is still using the standard pistons,inlet valves and camshaft. as I wasn't sure about what I was doing I ended up making a flowbench for pocket money, to give and indication of what I was doing and the following is copied from that post.
I know some people have big budgets for their cars, and mine is pretty small, but for me its about the challenge of doing something and following my ideas, rather than having people telling me I cant do what I want to. So when I decided that I wanted to port a cylinder head for my polo, I decided that I needed to do some research instead of just attacking a cylinder head with a dremel and hoping for the best. So I ended up making a flowbench for £15 (not including the wet and dry vac I already had.
so the idea of a flowbench is to measure the the volume of air that can flow though a port at variable valve openings at a given pressure drop. Now I know it can only do that at a steady flow rather that trying to replicate the dynamics of valve opening and closing etc that happen in the real world.
so I fell across this web page
www.dwyer-inst.com/Products/AirVelocityIntroduction.cfm
and then I began to play. now I based my flowbench on 40mm plumbing fittings as they are cheap and easy to get hold of and larger than the ports I was wanting to test.
so this is my version of two nozzles needed to make a pitot tube (which measures the air velocity and because you know the diameter of the tube, you can then calculate the volume of air movement)
and here it is in a tube (shown with an early very sensitive manometer that I used but then decided that I didnt need the accuracy).
I need two manometer, a small one to measure 12" of water pressure (to measure the air velocity with the pitot tube) and a larger 36" one to measure the pressure drop between the port and atmospheric pressure. I made mine from airline for fishtanks, a peice of wood and electrical cable clips
then I needed to make a valve to adjust the pressure drop, this is like a bypass that lets the vacuum suck in unrestricted air and is opened or closed to adjust the pressure on the larger manometer. I used 25 inches of water, which is just under 1 psi.
and then there is the plate that the pumbing tubing fits to the head. yes its mdf and the centre from a roll of cellotape, but since its bore is the same as a polo engine, its all good (and cheap).
and here is the final set up show testing a head. the two manometers are in the background and plasticine is used to smooth the air flowing into the port. bolted on top of the head is a plywood plate with a threaded adjuster that opens the valve 1mm at a time.
I also made a tiny pitot tube, so I could see the differences in velocity arround the port and give an indication about what I needed to do. its a 1/16" o/d tube inside a 1/8" o/d tube.
of course its not the worlds most accurate peice of equipment, but its fit for purpose. One thing that surpised me with flow testing is the noise, as it was deafening as I needed to wear ear defenders on the standard head. of course noise is vibration which is turbulance, so and the flow gets better the noise goes as the turbulance does.
and here is a early version of my smaller inlet port compared to a standard inlet port
with stardard mods on the engine (air filter, chip, exhaust) these engines normally have between 85 and 90 bhp (at the fly). with the headwork and modified inlet manifold I have 98bhp (at the fly) if I ever get the engine set up on a rolling road, I should be able to break the 100bhp barrier. my engine is still using the standard pistons,inlet valves and camshaft. as I wasn't sure about what I was doing I ended up making a flowbench for pocket money, to give and indication of what I was doing and the following is copied from that post.
I know some people have big budgets for their cars, and mine is pretty small, but for me its about the challenge of doing something and following my ideas, rather than having people telling me I cant do what I want to. So when I decided that I wanted to port a cylinder head for my polo, I decided that I needed to do some research instead of just attacking a cylinder head with a dremel and hoping for the best. So I ended up making a flowbench for £15 (not including the wet and dry vac I already had.
so the idea of a flowbench is to measure the the volume of air that can flow though a port at variable valve openings at a given pressure drop. Now I know it can only do that at a steady flow rather that trying to replicate the dynamics of valve opening and closing etc that happen in the real world.
so I fell across this web page
www.dwyer-inst.com/Products/AirVelocityIntroduction.cfm
and then I began to play. now I based my flowbench on 40mm plumbing fittings as they are cheap and easy to get hold of and larger than the ports I was wanting to test.
so this is my version of two nozzles needed to make a pitot tube (which measures the air velocity and because you know the diameter of the tube, you can then calculate the volume of air movement)
and here it is in a tube (shown with an early very sensitive manometer that I used but then decided that I didnt need the accuracy).
I need two manometer, a small one to measure 12" of water pressure (to measure the air velocity with the pitot tube) and a larger 36" one to measure the pressure drop between the port and atmospheric pressure. I made mine from airline for fishtanks, a peice of wood and electrical cable clips
then I needed to make a valve to adjust the pressure drop, this is like a bypass that lets the vacuum suck in unrestricted air and is opened or closed to adjust the pressure on the larger manometer. I used 25 inches of water, which is just under 1 psi.
and then there is the plate that the pumbing tubing fits to the head. yes its mdf and the centre from a roll of cellotape, but since its bore is the same as a polo engine, its all good (and cheap).
and here is the final set up show testing a head. the two manometers are in the background and plasticine is used to smooth the air flowing into the port. bolted on top of the head is a plywood plate with a threaded adjuster that opens the valve 1mm at a time.
I also made a tiny pitot tube, so I could see the differences in velocity arround the port and give an indication about what I needed to do. its a 1/16" o/d tube inside a 1/8" o/d tube.
of course its not the worlds most accurate peice of equipment, but its fit for purpose. One thing that surpised me with flow testing is the noise, as it was deafening as I needed to wear ear defenders on the standard head. of course noise is vibration which is turbulance, so and the flow gets better the noise goes as the turbulance does.
(totally)
Streetwerks
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- 132
- Location
- Chester
Streetwerks
Member
- Messages
- 132
- Location
- Chester
Working on a ported ST185 intake manifold today, few more hours work to get it finished but it's sure coming along well
Stay tuned
Streetwerks
Stay tuned
Streetwerks
indy4x
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I'm no porting expert but IIRC David Vizzard used to add rather than remove material to Ford Pinto heads to improve flow and performance which at the time was contrary to most 'other tuners' practice, hopefully someone can elaborate further?
Streetwerks
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If the head is badly designed like the port is rounded but not straight from the porrbline you get fuel drop out. Think of it like a back eddy or slack on a river when the bank widens from the main flow. Best way I can describe it. But not something you see on anything in the last 30 years I've seen.
