Cody1277

has anybody port and polished their heads, valves and throtle body? how much hp do you think that will make? i was thinking about doing it, but i don't know if $3050 will be worth it...the price includes the labor for taking out the heads.

thanks

Kennedy

iTrader: (2)

If you got that kinda scratch laying around, and are willing to tear into a perfectly good engine and void all your powertrain warranty, save another grand up and go supercharged.

Port and polishing will give you a very limited return/if any. These engines are not 350 chevy small blocks that reap great gains from PandP. Honda tunes the intake tract very well.
Not only that, a good PandP is useless without the ability to control the fuel delivery (ECU remap), which i don't believe is available yet.

CleanCL

iTrader: (4)

careful, the J series heads are notorious for losing power from being too aggressively ported. i feel a simple gasket match and polish. and especially anyone with forced induction. just remember, MILD porting. big bore throttle body is only as good as the intake manifold, get that PnPed too. and don't forget to replace the throttle plate with a thinner one.

gasket matching is as far as i would go, i wouldn't open the ports up past the gaskets.

Cody1277

Thanks for your replies. I forgot to tell you guys I have the supercharger already.

Cody1277

so i take it that no body in here has done the port and polish?

papiowhisperer

I looked into it a couple momths ago and
was advised against it for a couple reasons.
First, I don't think anyone here has the
technology to do it, especially the exhaust
ports due to the integral manifold. Second,
which is related to the first, nobody around
wanted to make the head perform worse
than OEM.

CleanCL

iTrader: (4)

i've had both upper/lower intake manifolds done and the throttle body.

Inaccurate

I am old, as in an old-fashion hot rodder.

The responses thus far are absolutely correct. The issue is matching the intake flow to the engine's requirements. More directly, the intake flow needs to be matched to the camshaft profile. So, the head porting would only be needed if you added a longer-duration camshaft. Also, blowers can benefit from head porting too even with the stock camshaft.

Furthermore, Honda has matched the flow velocities of the intake and heads to the factory camshaft. Enlarging the intake runners (incl heads) would slow the intake velocity, and you would loss AVERAGE horsepower.

CleanCL

iTrader: (4)

... i dont think i lost power from my PnP on my intake manifolds. low end torque is GREAT and it screams in vtec.

Inaccurate

Well, I forgot to include these terms in my post: "I speculate" and "Speaking academically" and "I have never tried any porting myself to really know" and ... oh, nevermind.

CleanCL

iTrader: (4)

although i would have to agree that port/polishing needs to done by a professional, not just your average metal shop, prefer someone who is honda knowledgeable or someone who does port/polishing for a living.