Skip to main content
Topic: Is there a benefit - port polish 8v (Read 50 times) previous topic - next topic

Is there a benefit - port polish 8v

Is there a benefit to porting and polishing an 8v PG engine (1991)?

Apologies in advance if this has been covered elsewhere. Sure it must have done but can't find it.

The engine is out of the car with the head off ready to be skimmed, cleaned and valve seats cut. So I want to know if porting and polishing is worth doing while it's in that state.

I've been told in the past that it doesn't make any difference, but it seems to be a standard element of engine tuning...


Re: Is there a benefit - port polish 8v

Reply #1
I'm sure there would be a benefit, the question is usually is the cost (both financially and effort) worth the gain. So if you're able to do it yourself or know someone that can then great. As you say it's already stripped down. And don't forget even if there's minimal hp improvement you may still gain from more efficient / smoother running and the current cost of fuel if you were able to improve MPG slightly then that would be a bonus.

Re: Is there a benefit - port polish 8v

Reply #2
I'm assuming that the engine is still charged?

I put a big valve head (inc port and polishing) on my old G60 Turbo, the result was I was making more power at the same boost level, allowing me to put it up a little more.
From what I understand, the 8v heads are a little asthmatic out the box and do respond well to fettling.
Mk2 Driver
Mk2 Silver 8v
Corrado G60 Turbo
Mk2 Red 8v
Mk2 Grey 16v
Bora 20vt
Mk2 Green VR6
Mk2 Green ABF
Mk2 BBM 20vt
3.2 TT Roadster
Mk2 Red 16v
225 TT Coup
3.2 TT Coup
Mk4 Anniversary

Mk2 BBM R32
Mk2 Red 8v