Is polishing your intake worth it

[vi top shatta]

I am wondering is it worth the time to try to get your intake ports polished. Also what kind of performance gain can I get. I am thinking about polishing my omc 3.0L, but looking at it getting into the block behind the intake ports might be very difficult. Any suggestion on the tools to make it possible. I'm located in the virgin island my tool selction is limited. Most of my stuff would have to be brought in from the main land (US).thanks for the help.

[Dave S]

Not so much pollish but open up to air flow. Get any thing sharp out of the way. Air will bend.... gas will drop if too sharp of bend. Don't take too much off it will mess with flow patterns. Drink before ya think before ya grind.... next day try to remember.:cheers:

[JP Love]

The best I see on dyno test : Match all parts and glass blasting after...

JP Love:thumbsup: for intake and transfert ports and polishing exhaust and booster ports...:thumbsup:

[JP Love]

After you see some change a bit... Some engine have better idling and funny quieter sometime... JP:thumbsup:

[beamrverbeek]

you dont want a polished intake. it will cause the fuel to puddle instead of staying atomized. thats why an injector sprays a mist of fuel, it is more explosive as a vapor then a liguid. a little blending and radius work will help but it wont be much of a gain unless something is really wrong right now. also the most gain you will see is high in the rpm range.


now if you are talking about the out side then polish away but it wont do anything for performance:D:D

[JP Love]

Good thread..................... :thumbsup:

[JP Love]

Injectors, carbs and direct is 3 différent engine.....

[Jay Smith]

I use crushed glass to blast my intakes ( front case half ) Always remember dry air likes slick surfaces, fuel vapor/air mix or wet air likes rough to improve adomize the fuel vapor.

my .02
Jay

[JP Love]

I use crushed glass to blast my intakes ( front case half ) Always remember dry air likes slick surfaces, fuel vapor/air mix or wet air likes rough to improve adomize the fuel vapor.

my .02
JayYES........... More power from a sand cast base than a die cast.....Atomazing.. :iagree:

[T-REX]

Polish tha outside........It'z purdier and git's tha same amount ov HP out ov it!!


Ole car words ov wizdom I ussa heer.....from carb to intake valve keep'r ruff, from exhaust valve on, keep'r like a baby's booty.....

JMO:thumbsup:

[beamrverbeek]

Injectors, carbs and direct is 3 différent engine.....


true they are different but the idea of atomizing fuel is the same. injectors do this by spraying fuel mist into the air flow. a carb has a lot futher to go yet stay atomized to get optimal fuel burn. so they work on the same principle just under different conditions. atomize, atomize, atomize. unless your reving to the moon, a good air fuel velocity is the key factor. open the runners to much and you will get a lazy air flow and performance will suffer. this is proven by todays smaller port designs, but have much better routing design so to keep a good air flow.

[BenKeith]

I use 80 grit spiral rolls to "polish" my whole charge path. I radius sharp edges and match all matting surfaces. Any bump, sharp edge, or other deformaties are going to cause a disturbance in the air flow. It does not take much of a deformation to cause a disturbance large enougth to disrupt and slow the whole column of air as it going through.

If it does not increase velocity, don't mess with it. In the ideal world you would want everything to have a one degree taper starting at the intake and tapering in until it went through the ports in the cylinder, basically a slight funnel affect, but that ain't gonna happen. There are always going to be areas in the charge parth that have increased volume and those areas are going to let the fuel puddle. Many times it's better to add material in the charge path than take some out.

I guess I should say that's what I've found on the fishing motors I've built for my bass boats but I'm wanting torgue as much as I'm wanting horse power.
If it takes 200 cfm to keep the cylinder filled at 6,000 rpm, why have a 400 cfm charge path feeding it.