RACEPAK

hello everybody.

i have a b16a2 that i'm currantly rebuilding for low compression with high boost.

i think i will keep the head stock because i cant afford new cams valves ect...

but i can polish the head intake ports myself with wet paper, and im thinking about grinding the orifice with a dremel to be knife like.

question is: should i even bother doing this just to the intake ports?
(i got the head allready disassembled to parts)

thanks.

best regards moshik galimidi

dasher

no.

projectTeG

id say leave the intake ports alone they need to be fough, but id say polish up the exhaust side.

adseguy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">no.</TD></TR></TABLE>
why?...just curious if you don't mind

nonvtecD

If you have to ask you shouldnt be screwing with the ports. If you don't know what you're doing you could definitely screw the flow characteristics and other things up. You're not going to be able to improve it without precise measurements and a flow bench anyway.

dasher

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">
why?...just curious if you don't mind</TD></TR></TABLE>

a) The Intake side shouldn't be polished because a polished smoothed surface will lower velocity.

b) The area highlighted(divider) is important to be left as is on the intake side to maintain port velocity.

adseguy

I knew some measuring whould be the problem..thanks guys

RACEPAK

I dont know why but i had the impulse to to it anyway. (only polish)

before
after:

projectTeG

why might i ask did you just polish the intake ports? you know they are suppose to be rough for a reason right?

CoreyR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">

a) The Intake side shouldn't be polished because a polished smoothed surface will lower velocity.

b) The area highlighted(divider) is important to be left as is on the intake side to maintain port velocity.
</TD></TR></TABLE>

polished intake ports are bad also because it causes the fuel to puddle and doesnt atomize as good.

RACEPAK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CoreyR &raquo;</TD></TR><TR><TD CLASS="quote">

polished intake ports are bad also because it causes the fuel to puddle and doesnt atomize as good.</TD></TR></TABLE>
but if the mixture is correct then your not suppose to have a piddle,

i polished them because i think it will flow better.

ps.
i also polished the IM.

splitime

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RACEPAK &raquo;</TD></TR><TR><TD CLASS="quote">but if the mixture is correct then your not suppose to have a piddle,

i polished them because i think it will flow better.

ps.
i also polished the IM.</TD></TR></TABLE>

Some air turbulence is key to atomization of the fuel/air mixture. You won't see polished Intake sides... you will see polished exhaust sides though.

projectTeG

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by splitime &raquo;</TD></TR><TR><TD CLASS="quote">

Some air turbulence is key to atomization of the fuel/air mixture. You won't see polished Intake sides... you will see polished exhaust sides though.</TD></TR></TABLE>

thats why when i polish my head i just did the exhaust side.

splitime

Here's some more info... I know there is a love/hate people have with Endyn... but whatever http://www.theoldone.com/articles/b16a%5Fhead/

SOHC_MShue

why would you polish them after so many people told you not to??? Fuel won't atomize as well like they said.

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RACEPAK &raquo;</TD></TR><TR><TD CLASS="quote">
but if the mixture is correct then your not suppose to have a piddle,

i polished them because i think it will flow better.

ps.
i also polished the IM.</TD></TR></TABLE>

You "think" it will flow better? You should have listened to the people telling you not to polish your intake side. Nevermind what you think about the mixture being correct and therefore the fuel not puddling, because that's just wrong.

Below is a something from Alaniz Technologies head porting.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">originally posted by somebody on Alaniz Tech

POLISHING

Polishing a port or combustion chamber does not alter the shape or size, but instead smoothes the surface to increase flow and reduce the build up of combustion deposits. On the intake side of an ALANIZ port job we give it a rough polish. Why? Your fuel injectors work in milliseconds. Ever wonder in 8 milliseconds how many degrees your crankshaft has turned if it is operating at 9000rpm? Your crankshaft has turned approx. 450deg. That means your injector has to start firing fuel way before the intake valve has even opened. Most of the fuel does vaporize as it hits the back of the valve but the rest of the fuel that doesn�t vaporize ends up on the walls, short sides and around the valve area until the valve finally opens and draws in the air fuel mixture. Keeping the walls rough in theory helps break up the fuel before it enters the combustion chamber. Atomized fuel burn better resulting in more horsepower and better fuel economy.</TD></TR></TABLE>

http://www.alaniztechnologies.com/headterms.html

RACEPAK

ok... nevermind. its not that i mirrored it, its still rough.

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RACEPAK &raquo;</TD></TR><TR><TD CLASS="quote">ok... nevermind. its not that i mirrored it, its still rough.</TD></TR></TABLE>

You might wanna think about how you wanna fix it. You might be able to take some really rough grit sandpaper and roughen up the intake ports. Before you do that though you might wanna ask around and see if it's a good idea.

Soccerking3000

you could gasket match it though, just dont make it all that smooth

CoreyR

mirrored or jnot its polished and needs to be roughed out. or you can continue to not listen to anyone and keep thinking your going to gain something from what you did. i would go with the first option if it was me.

Mrshorty

I agree with what most of the other are saying. Don't polish. When I do intake port work with porting tools, I stop with about 120 grit emery paper. Also, a knife edge on the leading edge of the bridge that divides the 2 valves will just create more of a restriction in the form of too much turbulence. Leave the bridge rounded on the leading edge, like the leading edge of an air plane wing. The air will flow past it better that way. If a knife edge worked better, air planes would have really sharp leading edges on their wings.

karmadhi

some exhaust sides port

RACEPAK

^^^ thats sHiny....

mine is not even close to that..

Flashmn

Exhaust side can be mirror shiny if you want, because theres no fuel dropout in the aircharge.

rpm11

Those carbon deposits on the valves in your pictures will really hinder flow, I've been porting for over 20 yrs and I never polish the intake side. My final finish is with a stone.