does polished ports on a vts add more performance

5th June 2011, 16:46

does polished ports on a vts add more performance

thanks

6th June 2011, 12:16

Port polishing on any car will add a slight increase on Bhp & Torque, but usually only with breathing mods, so yes it does

6th June 2011, 14:40

Yes it does, as long as it's good work, bad work can actually decrease power or make it run very poorly.

Headwork compliments breathing mods / cams very well and can make a nice difference to the power and torque

6th June 2011, 15:03

Quote:

Originally Posted by JamesR

Yes it does, as long as it's good work, bad work can actually decrease power or make it run very poorly.

Headwork compliments breathing mods / cams very well and can make a nice difference to the power and torque

Copycat

6th June 2011, 17:04

Basically no.
99% of companies will simply in effect randomly dremel around doing sod all to performance and charging you the bill.
Speak to someone like Sandy Brown Race Engines who actually develop these engines and know what will work and what will be a waste of your time and money.

Kev

6th June 2011, 17:40

Quote:

Originally Posted by Pug205

Copycat

I hardly copied you

6th June 2011, 19:32

DIY port and polish guide FTW

6th June 2011, 20:26

Sandy Brown ftw

6th June 2011, 20:40

Quote:

Originally Posted by J222JRA

Sandy Brown ftw

Sandy doing his own headwork now James. I know he worked very closely with sabre iirc so they did the work for him to his chosen spec.

6th June 2011, 20:53

It is worth it on a turbo'd engine though. Alays best using a flo bench of course.

6th June 2011, 20:55

Quote:

Originally Posted by tarzan

DIY port and polish guide FTW

ftl .

6th June 2011, 21:23

Quote:

Originally Posted by db_sax

ftl .

ftl? losers?

7th June 2011, 00:34

Quote:

Originally Posted by tarzan

DIY port and polish guide FTW

nothing wrong with it if you read up on it, practice on a spare head and dont be stupid.

7th June 2011, 05:49

Quote:

Originally Posted by Ryan

Sandy doing his own headwork now James. I know he worked very closely with sabre iirc so they did the work for him to his chosen spec.

I've never had anything to do with Sabre.
Mark Shillaber used to do my heads, up to the end of 2008, learnt alot of the theory and technique from him and evolved my ideas from that. All my engines including race engines, have had my own heads since then.

7th June 2011, 13:30

Quote:

Originally Posted by tarzan

DIY port and polish guide FTW

Its not really something the average person can do properly in their shed tbh

7th June 2011, 14:05

Making a good job of one of these heads, in my view is as much what you leave alone as what you change! The finish of the ports is not generally very important, other than to say shiny isn't what you want. By all means have a go yourself, I started as a DIYer; but unless your very flukey or unusually talented, you're unlikely to genuinely make it better without considerable experience.
90% of the talk about heads, relates to "flow", when in reality, these heads flow plenty well enough for most moderate spec engines... the benefits come from smarter attention paid to how the air/fuel and exhaust fluids move around, along with mixture quality and distribution. Likewise, valves have optimum sizes for a spec, rather than just trying to get in the biggest you can.
It all depends what you're trying to achieve though, if you're just trying to imrpove the peak bhp figure, the priorities will be different to trying to create a better power curve that will usually be a better way to improve performance.

8th June 2011, 18:46

yeah i see where your coming from mate about the diameter of the pot from inlet to valve. and im sure theres plenty more physics to it all. good thread and good read

8th June 2011, 22:53

At college I was told that as the air travels down the port it ''swirls'' so that as it enters the cylinder it mixes well with the fuel previously injected into it.(for a perfect explosion).
By polishing the ports you get better air flow but fuel will not be mixed with it as well.
So save the money and spend on something more effective. max

8th June 2011, 23:56

money is no factor when you already have the tools. save for cams

10th June 2011, 16:50

Quote:

Originally Posted by Sandy309

Likewise, valves have optimum sizes for a spec, rather than just trying to get in the biggest you can.

And this is exactly why my 400bhp+ engine is running standard sized inlet valves

Like I try and tell my missus - size isn't everything.

It's all about the throat (no pun intended).

11th June 2011, 15:34

i had a vts head rebuilt and ported and polished and when i got it fitted the car seemed to start making power a little further down the rev range. i never got it dyno'ed and i dont know if the difference it made was down to the head work or the fact the head was all freshly rebuilt.

25th May 2012, 17:55

[QUOTE=RossDagley;5367912]And this is exactly why my 400bhp+ engine is running standard sized inlet valves

QUOTE]

i am doing some of my own work on a 16v head. it is going to be a charged engine. i only plan to work the exhaust side as from what i have gathered this is more important and is suited to a boosted engine...

reson i am porting is to help make more power with less boost than on a standard head would require to make the same power.

25th May 2012, 18:17

holy resurrection batman

Exhaust side is the most important for sure. Are you planning on running the J4 or JP4 head? If you're going for a lot of power the JP4 is a better option, but the J4 is marginally better for faster spool in my experience, when not modified so much. If you're going balls out on modification on the head, start with the JP4 though.

25th May 2012, 21:56

j4 supercharged