Smooth as Glass intake

OROutdoors · Post by **OROutdoors** » December 18th, 2006, 2:36 am

A couple years back, I saw a process advertized in Import tuner, where in you send your intake manifold to the business which presses an abrasive play-dough like substance through it. The abrasives smooth the inner walls to a glass like sheen. I have been looking for that ad, but haven't come across it again. People I've asked don't know anything about it.

Does anyone here have a lead on the company who does this? Also, does anyone have any personal experience with it. What is is called?

Thanks in advance.

projectmx · Post by **projectmx** » December 18th, 2006, 8:06 am

you don't want you intake that smooth.. causes fuel puddling... your exhaust is what you want super smooth. but no can't recall ever hearing about this product... might talk to some shops or do some searches on google

jaydog5678 · Post by **jaydog5678** » December 18th, 2006, 8:56 am

projectmx wrote:you don't want you intake that smooth.. causes fuel puddling... your exhaust is what you want super smooth. but no can't recall ever hearing about this product... might talk to some shops or do some searches on google

He was talking about the intake manifold, which is fine for "extrude honing". The cyl head intake ports should be left rough for fuel atomization. The injectors aren't flowing through the intake mani, rather the cyl head.

projectmx · Post by **projectmx** » December 18th, 2006, 9:13 am

oh i guess that makes sense... didn't think of the fact the fuel doesn't flow through that part also.

OROutdoors · Post by **OROutdoors** » December 18th, 2006, 11:55 am

jaydog5678 wrote:
projectmx wrote:you don't want you intake that smooth.. causes fuel puddling... your exhaust is what you want super smooth. but no can't recall ever hearing about this product... might talk to some shops or do some searches on google
He was talking about the intake manifold, which is fine for "extrude honing". The cyl head intake ports should be left rough for fuel atomization. The injectors aren't flowing through the intake mani, rather the cyl head.

Thanks JayDog for the name of the process, I should be able to find something on "extrude honing" on google. That really helped.

This is the first I've heard of keeping the cylinderhead rough -- and I've seen many tuners show their work with pride ablout how smooth they have gotten their head intakes when porting them. It seems there is some debate of whether head intakes should be smooth or rough. I can understand both sides -- rough means more turbulance and therefore slightly greater atomization/mixture of the gas with the fuel. Smooth means less turbulance and therefore slightly more air gets into the cylinders which should allow for slightly greater compression.

Perhaps a good mod would be to have very thin rods extending through the intake between the injectors and the intake valves -- to increase the turbulance before just before the air enters the cylinders. Hypothetically, it should increase amotization. Or of rough sides are good, then how about scoring the sides with a Dremel moto-tool or shuch, that should increase the turbulance and therefore the atomization. Which is better -- increased atomization or increased flow? One is enhanced at the cost of the other.

jaydog5678 · Post by **jaydog5678** » December 18th, 2006, 2:37 pm

I would suggest just keeping the porting process as simplified as possible. You may want to talk to a head porter who does this full-time. You have to ask yourself what you are trying to accomplish with engine to start with, then go from there. N/A, turbo, nitrous, etc.. N/A engines don't like a whole lotta turbulence where turbocharged engines are just the opposite. With a turbo, you're just forcing air through the intake and it just so happens air tends to tumble alot.

If you want to know a little tip for added fuel atomization, then you could also mark just below the injector bosses "dimples", much like on a golf ball.

Steeb · Post by **Steeb** » December 18th, 2006, 4:35 pm

jaydog5678 wrote:
projectmx wrote:you don't want you intake that smooth.. causes fuel puddling... your exhaust is what you want super smooth. but no can't recall ever hearing about this product... might talk to some shops or do some searches on google
He was talking about the intake manifold, which is fine for "extrude honing". The cyl head intake ports should be left rough for fuel atomization. The injectors aren't flowing through the intake mani, rather the cyl head.

actually the fuel puddling was typically in the days of carb's where streams of fuel was sprayed into the carb

fuel injectors atomize fuel pretty well. its not that you need the ports to be rough but you dont want them too smooth. just dont over do it or make the ports too big to loose velocity.

Ice Racing · Post by **Ice Racing** » December 18th, 2006, 5:27 pm

You might want to read post "Acid Porting" under V6 Tech/Perf. You might find more about what you're looking for.

projectmx · Post by **projectmx** » December 18th, 2006, 6:29 pm

well mine are ported and polished the exhaust side is almost slick smooth and the intake side is very smooth but has a very slight roughness to it... the shop i had install my ss valves said it was a good job and exactly what was needed to have a mix of good flow and just enough roughness to help the fuel atomize

JWMotorsports · Post by **JWMotorsports** » December 18th, 2006, 10:36 pm

It depends on the type of injector and it's positioning method. There are a couple types of fuel injector spray types.

If your fuel injector nozzle has a direct line of sight to the intake valve(s) face(s) then you want to use pintle injectors with a typical 30 degree conical spray. With that setup you want the ports mirror polished as smooth as you can get them.

With the other sytle injectors or in a port where your injector doesn't have a good shot at the back of the intake valve(s) you would want a more turbulant port as they spray is a stream or a couple streams instead of a fine mist. Those applications need the turbulance at the injector nozzle to valve face area to help suspend the fuel in the air long enough for it to enter the combustion chamber. Other wise you will have a fuel distribution problems.

I know the b6t heads have a near perfect injector and intake port positioning. The conical fuel spray is divided at the ports and the intake ports come down on the valve faces at a very vertical angle. One way it could be improved upon (besides DISI injection) would be to rework the heads to position one injector per intake vavle with the 30* conical spray to miss both the port walls and the valve face giving you a nearly direct injection system.

In fuel injected engines (with the exception of TBI, so I should say port fuel injection) you want the intake and or IC pipes, intake manifold plenum and runners as smooth as possible. The smoother the surface, the higher the velocity can reach. This is due to less friction. On a highly modified engine larger runners and plenum volumes will help increase power. On lightly modified and oem applications you do NOT want to increase those volumes much at all, a little may help while a lot WILL hurt!

Port size should be no larger than the area of the intake valves it is feeding and any tapper greater than a couple percent per inch will in most cases cause the velocity to start droping instead of increasing. One thing you have to remember here is that if you can create a low pressure area the air will move to that area very quickly from the pressurized point it is currently occupying. Pressure waves can be harnessed as well or controlled by porting the intake ports a hair larger than the intake runner that is feeding it. This will help fight reversion in the plenum and also create a low pressure point infront of the intake valve (the bowl area). Unless you have money growing on trees this is the best method to use to gain power reliably, especially with forced induction. If you have a crap pile of money and time along with an entire setup you will NEVER change anything on than the ultimate efficiency is to harness the sound waves that come back up throught the intake valves (commonly called reversion).

The use of small dimples in the intake ports would work well as long as it is used with a poor port injection system, TBI, or carburated application. In a ideally setup port injection system like the B6T's for example, it would produce poor results compaired to a perfectly smooth port as the turbulance isn't needed to suspend the fuel in the air in this application.