Question for Ray and other clever okes!

[Zig's GS]

Firstly. To the administrators...I could not find answers under the search engine
Maybe Ray or someone else who plays with the ports can give me some advice here.
I am cleaning up the ports on my 1000 head ("big bore")
There is a HUGE step (downstream)on one side of the ramp that leads up to the guide.(intake side)
I HATE IT!!
I am sure it is not good for laminar flow and want to take it out but.....
Can I? Does it have something to do with keeping the flow to the side of the port. Is it put there intentionally or is it a bad tooling job?
Please....I am having nightmares about running down a tube and falling down this cliff!

[GregT]

I;ve done a few 8 valve heads and never struck a step like you describe.
Is it only in one port or all the inlets ?
If it's only in one it may be a core shift unique to that casting.

Any chance of a pic ?

Greg T

[Zig's GS]

I will try and take a photo tonight. It is on all 4 intakes and only on 1 side of the port

[Zig's GS]

Hope you can see what I mean

[Zig's GS]

And another 1

[Agemax]

i would leave it there. it helps direct the air/fuel mixture in the right direction downwards to the valve

[BadBillyB]

Firstly. To the administrators...I could not find answers under the search engine
Maybe Ray or someone else who plays with the ports can give me some advice here.
I am cleaning up the ports on my 1000 head ("big bore")
There is a HUGE step (downstream)on one side of the ramp that leads up to the guide.(intake side)
I HATE IT!!
I am sure it is not good for laminar flow and want to take it out but.....
Can I? Does it have something to do with keeping the flow to the side of the port. Is it put there intentionally or is it a bad tooling job?
Please....I am having nightmares about running down a tube and falling down this cliff!

The nightmare doesn't begin until you grind all the hump off....And then find out you have gone into the lifter bore and the motor now smokes really bad. Ask me how I know......Billy

[Zig's GS]

Now why did I not pick that up!
Thanks Billy, you saved me the costs of a new head!
Just gonna blend it in sideways slightly and then go and see a shrink. Will have to live the rest of my natural life knowing that there is a beeeg tabletop in my ports

[TheCafeKid]

Are you racing this bike? Or doing heavy Hi Po mods to it? If its going to be a "quick" street bike, I would think you'd want to leave some of that roughness in there. It helps to atomize the gas and make a better burn at lower throttle openings, where you usually tend to be in general street riding. Doing a complete port and polish on a street motor, from what Ive been told by more knowlegable people than i, could compromise low rpm performance a little. Would it be that noticeable? No idea.. just sayin, might ask some experts before goin whole hog on a port/polish..

[Zig's GS]

Are you racing this bike? Or doing heavy Hi Po mods to it? If its going to be a "quick" street bike, I would think you'd want to leave some of that roughness in there. It helps to atomize the gas and make a better burn at lower throttle openings, where you usually tend to be in general street riding. Doing a complete port and polish on a street motor, from what Ive been told by more knowlegable people than i, could compromise low rpm performance a little. Would it be that noticeable? No idea.. just sayin, might ask some experts before goin whole hog on a port/polish..

No, none of the above. I just like tinkering
It will just be a normal everyday riding bike but I want it to perform at its optimum. No Hi Po mods untill I have'nt sorted the brakes and handling first, but then.... it is an 25 year+ motorbike so I don't expect it to perform like a new GSXR and I am sure it still outperforms my riding skills!

[GregT]

While that hump may be there to accomodate the cutaway for the spring bases, it's worth checking while you have the head off.
I've done several 8 valve heads - 750 and 1000 - and in all cases there was enough material in the casting to streamline the guide boss and remove that bulge - although that's the biggest bulge I've seen.
Most gains on these heads - at least while keeping stock or fairly mild cams - come from cleaning up the area around the guides and the seat inserts.
Just my opinion...

greg T

[saffa]

so I don't expect it to perform like a new GSXR

you're not aiming high enough

[Zig's GS]

[ - although that's the biggest bulge I've seen.]
Why, thank you kind sir
I did streamline the outlet around the guide. It had quite a large flat area. I will keep the bulge, maybe make it a bit sharper (reverse pulsing?)
My head has a lot of casting marks and misalignment just below the seats which should make it flow better if matched