POTR Big Valve head Spec

[Mr Hans]

This is what Silvio sent me with regards to head specification.

"39mm inlet valve, stock is 36mm
33mm exhaust valve, same as stock but sodium fitted for high temps
enlarged valve seats
shortened valve guides for better flow in bronze for less friction at high temps, stock only exhaust is in bronze
polished and ported ducts
cnc machined valve seats, vacuum checked for optimum seal when valve is closed
uprated valve springs
skimmed and combustion chamber recess
special tcrime cum inside"

An additional note is:

"Head prices will increase soon, valves will increase soon, lot of labour, is hard to find good heads.......and need days and days of labour !"

[Mawbster]

current price for these is £540 including vat and delivery.

also nthanks for the specs james.

[CaL]

Thats not a bad price to be honest for an uprated head of that extent!

[punto gt3]

is that for a complete new head, or is that with sending your old one away?

[Mawbster]

the info i know is :-

the head is made from a tipo head. as its stronger . you can send the gt head away to be done but is weker and more prone to faliure. also the part exchange value of the gt head is minimal and will end up cosing you more in total as postage to italy is not cheap. better off just buying an item straight from potr

[Mr Hans]

Its outright new head.

[Punto_gt2]

did u get the sensor fitted mate, any pictures?

[PD_Punto]

are they still doing these heads?
is this as good as i gets in the way of a punto head?
what bhp will it run before being on its new limit. also what is max safe rpm. i have a top secret project hoping for 9_10k rpm but i have a feeling the head will be the week link??

[Debo]

is this as good as i gets in the way of a punto head?

No, far from it. Hans is trying to be smart when he says a 2011 head is better than a 2001 head, that's his defence on what I'm about to say next:

Just get it done by CNC Heads - they made a better flowing head than the POTR BVH using standard sized valves, first go, catching up on 15yrs experience and bettering it in 15hrs. They cut up a standard head to work out the water galleries and wall thickness of the ports etc, then used a computer to design the optimum flow, ported the head with a cnc machine then finished it by hand. At certain parts of the valve lift, especially the early part, the POTR head was flowing less than standard and overall looked very poor (lots of turbulence in the ports, and can be seen by a wavey line on the flow graph). Waste of time IMHO, just get proper headwork done, Hans said himself, "good head is hard to come by". You don't want to spend your money on something that is worse than standard.

I have had all 3 types of head and have flow graphs of all 3 and one combining them all - the CNC head reigns supreme and by a wide margin, it flows over 20% more air on both inlet and exhaust - crucially it flows this 20% more from the beginning of the valve lift, you read a flow graph like a power one, it's not the peak figure we're looking at, its what's under the line that counts - POTR head was only any good at .5" lift, no Punto cam lifts that much, rendering the head worse than standard since it was behind for the majority of the valve lift.

[Mr Hans]

Everyone will have their opinions and without starting a debate....Good head is hard to come by. POTR aren't really making heads much these days because from a business POV its not great money.