Porting heads for more power

[qca]

what about port reversion ????
how far does the intake charge (which is wet)rip back up the intake port before the intake valve is re-opened causing wet port walls valve stems etc. anyone thats taken an inlet off an EFI
engine knws of the build up in the intake manifold all the way to the throttle body. rough it up.with no knife edging

 

[SCV8]

Better not do anything then, heck, it might not work.
LOL

 

[KweazI]

A carbie actually mixes fuel and air better than an EFI system
The smooth polish will lower the amount of friction therefore lowering the amount of turbulence which will mix the air even worse
i dont think it will affect the performance too badly unless u had a really high flowing big bore type of system with ultra high comp, but it wont be as good as it can be if u have smooth porting like that

 

[COFFEE]

To all the above,
After reading this very long thread and having been told the same things as a lot of you are questioning, would it be fare to say that the ideal way would be to match port the lot, mirror polish everything prior to the injectors as ther is no fluid to be concerned about de-atomising and leave the head ports slightly rougher ?

This may sound crazy but i am suprised that no one has tried cutting shallow grooves into the walls of the intake path in spiral patterns ?
I would think this may cuase the air to pressurise ? just a crazy thought !

Regards

Stephen

 

[MaxPower]

This may sound crazy but i am suprised that no one has tried cutting shallow grooves into the walls of the intake path in spiral patterns ?
I would think this may cuase the air to pressurise ? just a crazy thought !

Big dollar CNC ported heads have something similar to this, works very well.

 

[MWP]

You guys are forgetting that factory sequential injector setups actually are designed to spray the fuel onto the back of the inlet valves while they are closed!
They do not spary the fuel while the ports are open.

This causes the fuel to evaporate immediately giving more even burn patterns in the cylinder.

So if your engine does have sequential injection, and the injectors are very close to the inlet ports, dont worry about fuel/air suspension.
Give those ports a mirror finish

 

[george]

factory injectors are fired in a group no sequential.

 

[MWP]

The VVTI 1UZ and 3UZ should be sequential.

 

[vn1uz]

Americas Cup boats actually have a finish on them like a Dolphin or shark. small ribs in the finsh to improve water flow.

This was first used in the Challenge against a Australia by the Yanks in the mid 80's.

Why do footballers use shark skin (foot) balls in the wet?

Because they are rough and help them hold the ball.

I don't think sharks would have skin designed to slow them down. I know there are a few swimmers who have wished they did!

look at the swim suite that thorpe wears ? same thing
when i use to be right into sailing we would wet rub the bottom of the boat with 400grit to have a smooth but still a little rough surface as soon as a bit of waster hit it it would be heaps more slippery than if you did it with 1000grit

but that is all water flow how different is air ??
i still think it would be the same though

 

[SCV8]

That's how I've done my better port jobs; polish first, then go back with 400 paper.
Haven't done the SC though.

 

[ballo]

what sort of tools are used to smooth the inside of the port especailly in regard to polishing?? as im about to take on a job not unlike this very shortly where alot of small areas exist that need polishing.

cheers

 

[SCV8]

A good selection of carbide burrs as they are called here in the states, different shapes are used in a small grinder for the various profiles and angles that you must work with/around in order to acheive good results.
An important thing to remember is to do everything in stages, don't try and do one port all out, then jump to another. Just do a little of the exact same work on each hole, then go on to the next operation.
Do some research by reading up in some reputable books before, it'll make it easier.

 

[COFFEE]

Staff,
I am just curious, did you take the head ports out to the gasket lines ?
Could you PM with some details on your job shown in this thread.

Greatly appreciated

Regards

Stephen

 

[n4087607]

one of the previous posts mentioned that the skin of a dolpin under a microscope looks like VVVVVVVV, so does everything to a certain degree. If you over polish things it flattens this profile out meaning that contact occurrs over a greater surface area which increases friction. There is a fair bit of information on this topic within the solid film lubricant area, don't know if this is usefull or not but there you go.

 

[Nath]

I read an article in scientific americia about a mechanic biek racer in india who was deliberatly grinding valleys into his head chamber in a star pattern. he believed the valley created an huge amount of turbulance on the compression stroke that every bit of fuel atomized and was burnt. He believed his bikes were unbelievably quicker and he had done several bog standard cars and the improvements in tourque were huge. Also his fuel useage decreased as he wasn't wasting fuel.

It was not supported with any figures or tests but would be a fun test for the ford lazer when the head gasket goes.

Worth looking into I think, espically if you could cnc the pattern the same for each chamber.
Nath

 

[WDoherty]

Anyone have dyno results or e.t. numbers from head porting alone?

 

[Lambo]

Hi guys, I was told many years ago by an old drag racer to sandblast the inside of the intake runners, this allows the fuel to atomise better not just run in droplets down the runner, i guess it really only applies to Carbs though.

Regards
Lambo

 

[Pro]

my experience with porting and reading up on "the god" David Vizard (and the other David of course!), the gains and pitfall of both polished and pitted inlet surfaces equal each other out.

polished makes fuel "stick" to it and create more friction - but air speed is up, pitted you lose air speed through turbulence but the mixture is better.

Look at a things in nature that travel at high speed through fluids. I can't think of anything that has a mirror finish.

explain a dolphin then? sharks are rough and fish scales create air pockets between the fish and the water reducing friction.

a test was done YEARS ago re: golf balls.
a golf ball was shot out of an automatic launcher thingo , and the shiny, smooth ones would all travel ~ 100 metres. when they pitted it(like they are), the air couldn't "stick" to it, and it flew 300 metres.

you'll get more gain working on the "short turn" shape on the inlet than anywhere when it comes to porting. make it as straight as possible and watch the power and torque figures climb.

 

[SC4LIFE]

i have a question for ya. I was going to get headers put on but now if u say it is only like a 8 hp gain then its not worth it. i thought it would be much more. i have a stock everything i was going to get aftermarket spark plugs, headers, airintake, and a true full dual exhaust system. what do u recomend me do. im a beginer with some money? i just want to do alot of little stuff that adds up after awhile into horsepower.

 

[Zuffen]

I would do the exhaust first.

If it won't breath you won't get any other mods to work.

Headers alone won't do the job. You need an engineered exhaust.

JBrady hs written heaps on the best exhaust system for an LS or SC. Follow his advice and you'll do well.

A BFI (bigger air intake) and CAI (cold air intake) will improve performance.

Quality spark plug leads, fresh plugs and an ignition system in good nick (no daggy old 100,000 mile dizzy caps) and use the highest octane fuel you can afford and you'll see and feel performance gains.

Don't fall for the pod filter in the engine bay trick. Feed the engine thru a quality airfilter (some pods are excellent) breathing the coolest air you can give it and you're looking good.

After this it's cams and then aftermarket management and a MAP snesor in place of the AFM.