This may sound crazy but just something that I was thinkin about......
Seeing that our TPI systems flow "dry air" meaing that there is no gas suspended in it. Couldn't we polish the intake runners on our heads? like you would on the exhaust port???
I know that on carbed engines they say not to polish the intake side of your head because you don't want the fuel to drop out of suspension and that you do want some roughness for turbulance....... but wouldn't you want as much clean undisturbed air firing into the cylinder if you could have it that way with a TPI system???
I was looking at the 5 axis CNC'd Air Flow Research heads in Chevy High Performance magazine this month and they look so smooth!
Opinions?????

 

Um, how do I say this. Take a look at your engine. Notice where the fuel injectors are. They are in the intake manifold. They spray FUEL into the INTAKE PORTS on your head. Only the TPI intake manifold, up to the injectors, is "dry", as opposed to a "wet" TBI or carb intake. If your heads flowed "Dry" too your car would not be running (or maybe it would be running on some sort of solid rocket propellant sprayed in powder form? Solid fuel injection?)

 

Wait a minute, easy does it... I think MOST of us realize what I was talking about when I said that the TPI was a dry system.......
Looking at a cutaway of the TPI intake attached to the head there is only like 3-4 inches tops to the intake valve from the injector itself. And the injector is spraying at anywhere between 40 and 50 lbs/hr which creates a pretty good fog. I don't think that the fuel is magically gonna puddle if that's the case....?

Solid Rocket Fuel.... Good One. Try thinking outside the box sometimes. It's a shame that some would rather Haze people and Ideas rather than think with an open mind and contribute constructively.

 

Anybody?
Would polishing the intake port on your head hurt or improve performance?
I ask because of the difference between a TPI System and TB/Carb systems? I plan on doing a head change in the near future and was interested in different opinions........ Seriously!
I've always read about the advantages of polishing the exhaust port, but haven't seen any information concerning specifically the intake port on a TPI system...... Wouldn't polishing the intake port keep velocity up rather than running into rough port material, even after porting?
Just throwing it out there

 

maybe try it in gen tech . You may get more responses. I think you need that rough area to break up the flow . Although thats what the plenum is supposed to do . So who knows maybe it could benifit ....but I couldn't say myself .

 

People do it all the time without problems. If you're really worried then the obvious choice for you would be to just not polish the port floor in the head.

 

I still think the smooth surface would pull the fuel out of suspension as soon as it came in contact with it, regardless of distance and pressures. I wouldn't do it, IMO. But that's just me and I could be wrong. I'd be curious to know if anybody's done any scientific testing on this. I'd much rather port-match all the intake pieces and save any polishing for the exhaust port and the intake tract upstream of the injectors

 

Thanks Gents! Anyone else? opinions, ideas, personal experience appreciated........

 

Polishing the intake port will make virtually no difference in airflow. Air does not flow at the same rate all thru the port. The air near the walls is barely moving. It is stuck to the wall regardless of their finish. As you get further from the wall (say 1/64 or so inch away) the air picks up speed. Therefore there is very little to be gained by polishing the wall. All it does is make it look good for the customer. It may however cause fuel droplets to form on it. Everything I have ever read about airflow/porting/polishing says dont do it.
Roy

 

stock tpi injectors are no where near 40-50lbs/hr.

i've always heard its not good to have them super smooth like glass like exhuats ports. just keep a little texture to it

 

maybe they are thinking 40-50PSI?

 

you can port the the intake ports, just not "polish". You can rind the crap out of them to get better head flow, just don't polsish it up after you're done grinding. same goes for carb. You want to leave a "rough" surface. i don't think it would be as critical on a TPi motor, because the high fuel pressure itomizes the fuel as it's sprayed. why do you think we can gain power from upping our presusure? beter fuel atomization. - i still wouldn't polish it though.

 

Thanks guys for the different insights..... Thought that it could be a pretty good discussion once everybody took the time to think about it.
If I ever do polish the intake port I'll make sure to tell everyone about the results......... In the meantime I guess I'll do more reseach........
Like I said before it was just a thought???!