Polishing the intake ports and bead blasting the area after the injectors would prove fruitless as rpms increase....as the air in the port speeds up, the bead blasted surface after the injector would not atomize the air properly.

Proper agitation of air (induced turbulence)well before the injector is crucial to maintaining the air /fuel atomization in order to avoid the "Wetting" of intake ports/intake valve bowls and valves....which can develop sludge over time with subsequent hotspots causing predetonation and pinging as well, not to mention changing the geometry of the port and airflow.

The immediate comparison of output between a polished and textured ported intake port is negligible. it is the long term effects that are the bombshell.

Polishing the port alone will not increase port velocity....it is the port shape/configuration that affects velocity. Per Boyle's gas law....port size (volume) has an inverse effect on (Pressure). As a port size decreases from inlet to transition), the air velocity in that port will increase. If a port is made
constant or too large, the air charge will slow down and be subject to unwanted turbulence and or reversion.

A good study of physics, chemistry and fuid dynamics would yield lots of knowledge....but what do my engineering instructors know?

My major is Mech engineering. Special emphasis on vehicular propulsion.

 

"Proper agitation of air (induced turbulence)well before the injector is crucial to maintaining the air /fuel atomization in order to avoid the "Wetting" of intake ports/intake valve bowls and valves..."

-A Tornado perhaps, God help us -hehe

Thanks for the info!

Good luck in your studies, They have come a long way since I was in school (ME), back in the days of slipsticks... The first handheld calculator$ were introduced while I was in Engineering school. We programmed with cards and paper punch tape. My emphasis was materials and economics.

 

I believe Edelbrock introduced a manifold about twenty years ago or so called the "Tarantula" which exploited this very concept. They cast the manifolds porposely with cobby intake runners and plenums. The theory is, and it's proven, the turbulence keeps the A/F mixture from separating. Any droplets collide with the rough texture breaking them up.

As far as the Tornado goes, if it works at all, I am convinced it cannot do much for ported injectors. Carburetors may benefit but the fact still remains, the turbulence it creates is above the carburetor, not between it and the intake valves.

How soon does that turbulence smooth out once it passes thru the plenum is left unsaid. Velocity can straighten out a rough wind.

 

The pressure differential from a textured surface alone is enough to create induced turbulence, I really don't think the tornado does much but twist the air a certain way and by the time the air gets to the valve the effects of tornado are useless.......the best way to make air swirl is to create a pressure differential inside the valve pocket above the valve where the port pressure/velocity is at it highest, the offset side of the valve guide needs to be ported a bit deeper (low pressure) and have a smoother rake towards the rear of the guide...the straight side of the port needs a shallower depth with a more aggressive rake towards the rear of the valve guide....(leave this work for those who do this for a living, it pays to pay the money for this....in other words Do it yourselfers can easily ruin a set of heads trying this)

here is a pic of the intake valve pocket/bowl that depicts what I said.
http://www.replikamaschinen.com/Web_...%20chamber.jpg

the air moving past the texture creates induced turbulence (induced drag) before the injector that will aid in keeping the injected fuel in suspension even if the valve is closed at that time....this means less varnish and getting the hp you should be getting while keeping carbon build up at bay...

If Ford engineers though that a smoother surface was need, I am sure the cast molds would have been made to reflect that.....these guys get payed 6 figure salaries (or close to it) in order to solve problems that arise via trial and error or knowledge and experience.

Unfortunately, there is a large range of use for these trucks....so specific port sizing, valve sizing, bore and stroke has been designed to serve a multitude of uses. This is why it is up to us to "tune" our trucks to our specific uses...

I like the idea of being able to lay rubber on the road with 32 inch tires and 3.55 gears.

 

Actually, Capone, I believe Ford does rework intakes. As I recall the SVT's (or some other high output engines) have some type of polishing grout pumped thru the runners or ports at high speed to smooth out passages.

I absolutely agree with you on everything else.

I believe Ford also experimented with swirl heads about 20 or 25 yrs ago. Yamaha was providing them, if I remember correctly. Swarup made swirl heads you could bolt on, too.

The Tornado was installed on a Honda Civic, (a fuel injected model post 1992), and it actually lost hp and torque at certain rpms over stock intake on a dyno test.

Also, a Pontiac enthusiasts website did the same test with similar results.

 

Great discussion guys! I've learned alot about good and bad things to do. So just to be sure, I'll outline what I think I should be doing to both the intake and the cylinder head. Please correct anything you think may be wrong.

On the intake - just smooth the casting seams and remove any bumps. Maintain the rough surface texture and general shape of the runners. Should I knife-edge the openings where the runners separate from the plenum? It's pretty rounded over right there.

In the cylinder head - DON'T GASKET MATCH. On the intake side, just smooth any casting seams, sharp edges and corners. Easy on the bowl work. concentrate around the valve guide (nice pic, Capone!) and short side radius. On the exhaust side, same smoothing work as the intake, but polish to a shine. Port the exhaust runner opening to match the header?

Capone, in your explanation of the pic, you do not specify what the offset side, straight side, etc. of the bowl is. Makes it hard to follow your description of the work to be done. Need to go back and read Vizard and Std. Abrasive DIY page to clear up my thoughts.

 

The same misalignment problems are present on the header side. The header opening should be about 1/16" larger on all sides than the exhaust port in order to avoid any "ledge" that the gas flow may see. The ledge that is formed by the head port being smaller helps also.

Remember that you may be replacing those headers at some point and all of your port work would have to be done over or maybe even heads replaced if the new headers don't fit like the old ones

 

re:Actually, Capone, I believe Ford does rework intakes. As I recall the SVT's (or some other high output engines) have some type of polishing grout pumped thru the runners or ports at high speed to smooth out passages.
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Yes, they indeed started to "Extrude Hone" SVO, SVT items to increase port runner size not to polish it....it was done this way because the turn around is much less than hand porting or redoing the cast molds....

Now with the advent of CNC porting, the turn around times will be halved if not thirded... (yeah baby!!)

I also stated that Auto engineers found that the cast finish worked best for longevity of vehicular operation for the average daily driven cars....race cars get teardowns on a normal basis so their design parameters/criteria are different....

Ford engineers rework lots of foundry components to improve performance.....this is why they formed SVT, SVO and Ford motorsports in the first place.....Ford execs forsaw the profitability....Consumer Demand dictates what auto manufacturers will do...

Look at their GT40 heads....GT40P, GT40X, GT40Y, Yates, Blue thunder etc etc....

Injected Ferrari engines also have the smooth but textured intake ports....
I have also seen Lamborghini heads with the smooth but textured intakes...

Getting back to your questions:
Should I knife-edge the openings where the runners separate from the plenum? It's pretty rounded over right there.
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the answer is no.....keep the contours rounded.....just make sure to enlarge the entrances to the ports from the plenum and make sure they taper as they head towards the head mounting surface of the intake....make sure that the ports in the head also continue this trend right up to the riser before the lower radius. (this will ensure the port velocity increases thus good low end torque) standard abrasives shows a side profile of an intake port depicting the reduction in intake port size i just described.

Now as for the intake valve bowls....the intake will have an offset (usually on the right side......as you look at the head from the intake side....)
and have a straight configuration on the left side....like a lopsided elongated tear drop shape.

Just make sure to smooth the stock shape....and turn the valve guide boss into a tearshape at the base....blend it in as you move up....it should look like a little volcano...this will maximize bowl volume while keeping velocities high and reversion down.

Blend the bowl smothly into the valve guide....just like the pic

exhaust ports: keep the small side of the valve guide boss small and bend a path around it on both sides....smooth any lower radius bumps or ripples...look at the picture i posted...polish that badboy like no one's business...

Port the exhaust ports a tad smaller than the gasket allows....(for gasket adjustability...the opening as a rule of thumb should always be just about even or slightly smaller than the header opening

I can email you pics of intake or exh port work in progress...
Just shoot me an email...