Porting and pollishing Valver head

[scoobs]

Looking to do this once i get my new engine and am rebuilding it.

Are there much gains to be had?
I'm just going to do i t myself, is there any one done it and have any things i should know, such as,

Are the water galleries close when porting?

I''m not doing the valve seats myself obviously. jsut the ports

I have a Old head at work i am going to practice on first.

[MAXIBOY]

not worth doing unless your an expert really as most gains are in the throat and seat area. good head will see as much as 20bhp though with the correct complimentary mods

[bill.]

not worth doing unless your an expert really as most gains are in the throat and seat area. good head will see as much as 20bhp though with the correct complimentary mods

what do you mean by that exactly? do you mean for example along side, other mods such as cams etc? i take it you dont mean a modded head could be worth 20bhp on its own :shock:

[mikeymikewakey]

I would say so, don't see why not.

Im taking my head to port-formance for bigger inlet valves, flowing in the head and inlet manifold matching on 23rd july so I shall let you know :)

Mike

[MAXIBOY]

yes a good head will see between 15 and 20 bhp on its own. but if you have a really well modded head with a lot of peak flow gains it may need better cams with higher lift to take full advantage of it.

[bill.]

I would say so, don't see why not.

Im taking my head to port-formance for bigger inlet valves, flowing in the head and inlet manifold matching on 23rd july so I shall let you know :)

Mike

whats that costing you pal, if you dont mind me asking? pm us if you like, your giving me ideas now 8)

[bill.]

yes a good head will see between 15 and 20 bhp on its own. but if you have a really well modded head with a lot of peak flow gains it may need better cams with higher lift to take full advantage of it.

:shock: jesus, didn't think they where worth that many extra horses 8)

[MAXIBOY]

average price of a good head with larger inlet valves is between 600 and 800

[DaveH]

I may be wrong about whos car it was but scottcup (now summeh's) cup car had his head work done at portformance and that put out 180bhp afterwards (standard cams) obviously he has breathing/exhaust mods but you get the idea of what is possible, i was also told that the same company has managed silly amounts of power out of evo heads but at the same time made relatively small amounts on a vr6 head. Its all dependent on the original design of the head as to how much power can be extracted from it but one thing is for sure even if its only a slight bhp increase on paper you should easily notice the difference.

[alex_e3]

Slightly off topic - but which head is better to take to a company to get porting/polishing done: standard 16v head, or standard willy head?

When i finally get the willy engine up and running, i wanna have head work etc... done in the future. However, i can't do without the car for 2 weeks, so could do with getting a separate head done, then just swap it over.

I've read somewhere on here that 16v heads are better for work, as there's more there to start with - true or false? I'd be going for the top end of headwork bear in mind.

[MAXIBOY]

williams heads are slightly better as they have slightly larger inlet valves fitted as standard.

[alex_e3]

But if i was going down the big valve option anyway..........??

[MAXIBOY]

then either way you need to fit larger seats and i dont think there much in the castings really. i understand that if the valver has smaller valves then there will be more material around the seat area but i,m not sure that when fitting big valves that just means theres more to remove out the way.

pm stan on here as he will be able to tell you as he does this for a living. and would be the person i would use for big valve heads.

or there is portformance as they have a good rep on here.

[AndyFielder]

que the whos better flow graph show down!

[MAXIBOY]

flow graphs are the starting point. back to back dyno tests with each head.

[AndyFielder]

that hasnt been done has it? same car, just changing the heads.

[MAXIBOY]

not in this instant. seen it on other cars though with heads, cams etc.