Port and polish

[novanova636]

Hi all. Im giving my head a clean up in the ports. In both the inlet and exhaust there is alot of valve guide/sleave sticking out into the ports and was wondering if anyone has had there head done profesionaly and did they grind these down? Looks like they will spoil air flow quite alot. I cant see how it would affect the valve if the guide/sleave was ground down bu thought id ask just in case!!

Cheers Dave

[Pistol Pete]

I dont think its an issue AFAIK. I think you can see the valve guides on most head inlets TBH.

[novanova636]

Would it not be better to have it completly smooth tho?

[Pistol Pete]

Valve guides are round, so not going to affect flow greatly i wouldnt have thought.

[meritlover]

anything protruding into the port regardless of shape will cause a pressure drop and reduce flow. yes on ported heads the guides are often cutback or if the guide is too short to be reliale, the ends are turned to a taper.

[philip]

what head is it?

if porting them for people (8v heads), i cut the guide back and part of the casting so the ports are smooth with a decent radius. wont cause any problems for valve seating just make sure you clean/deburr the guides

[burgo]

aim to achieve this and you wont be far off

http://i80.photobucket.com/albums/j181/mikenova/TWOC%20Rebuild/109_0435.jpg (http://i80.photobucket.com/albums/j181/mikenova/TWOC%20Rebuild/109_0435.jpg)

[chimp007_uk]

then you want to waste the stems ;)

3 angled valve seats increase the flow the most. epends if your budget can stretch to that!?!

[burgo]

if i had a mini laith i would of done. you can buy me one if you want

[chimp007_uk]

me??? buy you one...?!?

I might be redundant in 3weeks... woohoo :(:(

Ah well, I'll hone my sexbox skills ans kick your ass

[burgo]

baaahahahahaha +rep for the funniest thing ive ever heard

[chimp007_uk]

You wont be laughing when I become don COD4...!

Ah well, **** happens, got to make the most of my 2weeks testing in spain as we find out when we get back who out of the new 4 is going and staying. They're selecting 2...

[novanova636]

that pic is what i want to see cheers dude. How thin would you suggest to go on the valve stems? I can machine some down for people if they want!!
Do you play cod5?

[Adam]

What head are you planning on using?

[philip]

dont bother trying to waste the stems yourself. bad advice for home builder imo!

[novanova636]

its the head off my 1.2 carb engine. Im a precision enginer so i cut metal all day long!!

[philip]

if you can watse them then go down to maybe 5.5mm(presume stems are 7mm) but only where there exposed in the ports:)