Ported and Polished Heads?

[ScubaTermi]

Anyone ever have their heads ported and polished, if so what kind of numbers can one expect to gain?

 

[Jimmysidecarr]

On sub 700 rwhp cars I will go out on a limb and say that 90% of whatever gain was recorded, if that was the only mod(which is practically never) was gained from the freshened valve job and the tight new guides.

Yes I'm serious. If I was doing it I would spend the money on guides and the required valve job after the guides and that's it.

You don't want the intake port polished anyway.

Now if they had ceramic coating available for the exhaust ports and I wasn't running cats, I would be all over that. It would be nice on the piston tops and combustion chamber too, along with some kind of piston oiler jet machined into the connecting rod.

 

[SlowSVT]

On sub 700 rwhp cars I will go out on a limb and say that 90% of whatever gain was recorded, if that was the only mod(which is practically never) was gained from the freshened valve job and the tight new guides.

Yes I'm serious. If I was doing it I would spend the money on guides and the required valve job after the guides and that's it.

You don't want the intake port polished anyway.

Now if they had ceramic coating available for the exhaust ports and I wasn't running cats, I would be all over that. It would be nice on the piston tops and combustion chamber too, along with some kind of piston oiler jet machined into the connecting rod.

+1

Not much bang from the buck porting 4 valve head in a blown application. I've seen a few post with back-to-back dyno runs which typically see a 25 hp increase with a $2000 full on port job on a high end motor.

Jimmy

I was thinking along the same lines about ceramic coating the piston crowns and combustion chamber. I did some pocking around and read an technical article which stated they noted the engine was less tolerant to ignition advance due to the rise in the compression temperature after ceramic coating the chamber. Seems plausible. I will be rebuilding my heads and plan on ceramic coating the exhaust ports and exhaust valve to minimize the heat that poor valve guide has to deal with.

 

[CobraBob]

Here is some other helpful info from JimmySidecarr. Is it worthwhile to port my Terminator heads?

 

[untitledreality]

Not worth it for a street car... these heads flow so well already that your money is better suited somewhere else.