Is it worth doing?

 

What are the pros and cons?

 

I took my head and block to a local engine shop and he said it's not worth doing but if that's the case why is it so many people get it done. So i'm after other people advice.

worth it if you're going with bigger cams

what are the benefits of doing it?

I think they flow well as standard as they were desgined for performance .But as there off the car they carnt do any harm, especaily get rid of the casting marks etc.I cant see this on its own will see any extra bhp but may help flow further up the tuning level.

they have been cleaned and skimmed.

Benefit is not as pronounced with a turbo engine as an NA, small percentage increase really, fairly high cost, but once you get further up towards the high end of tuning then you would probably want to get it done.

Benefit is not as pronounced with a turbo engine as an NA, small percentage increase really, fairly high cost, but once you get further up towards the high end of tuning then you would probably want to get it done.

 

also get it done by someone with experience of porting. it can actually be detrimental to performance if you just go grinding metal out of the ports without knowing where to remove it!

Cool ok, I'll do some digging around for companies close to Norwich.

>> Polish and Porting, Is it worth doing?

 

only when fitting larger valves and more aggressive cams (imho)

When I was a fitting & turning appy, we polished the intake of a Mini Cooper (1275cc). After a run on a dyno it produced less power and torque than when compared to the same engine fitted with the non polished intake. The air leaving the carb was flowing TOO smoothly into the cyclinders. Needed the casting marks and the rough surface ffrom the sand casting to 'tumble' the air flow.

Not sure how this relates to the head but I'm bored! Interested to hear if anyone elso agrees with the intake side of things though! :cool:

How much did people pay for Polish and Porting??

 

Just quoted £475+vat is that a good price?

I'd say it's expensive for the small gain you'll achieve. An NA would normally see a better gain than a TT, for obvious reasons.

An NA would normally see a better gain than a TT, for obvious reasons.

 

That's just not true but a very common misconception.

Simply if a ported cylinder head gives 20% extra power on a N/A engine it will also give 20% extra power on a turbo'd engine (as long as the turbos etc can meet the flow demands). May even be more once the heat drop is taken into account from running the turbos at a lower boost pressure to achieve the same cyl filling.

OK, that's a good point, I'd not thought about it in that way. My view was simply that the basic flow being less smooth on a TT will make less difference as the gas is under pressure and 'bursts' though as soon as the valves are opened. Whereas an NA will have a harder job of drawing the air through if the passage if more obstructive.

lol you've kinda lost me,

 

So in other words with uprated cams and turbos it is worth the £475+vat?

 

20% seems a good power to gain to me.

20% is just an example, if you get the right place to do the work they'll have a flow bench and be able to tell you the actual difference before and after.

here is the place http://www.scholarengines.co.uk/services.html

 

Ap-tuning using them and so do Henstead so i think they have done many before.

 

From what little knowledge i have this place looks fairly kitted out.

Not sure if they've done many 300s but scholar produce some really top end race motors. You could be pretty sure they'd do a good job I would think.

Oh good, that's good to hear.

 

They are only about 20min from mine.