Cylinder head porting?

[VTRDark]

Thought this to be the appropriate place for this. I found an interesting article on cylinder head port/seat design.
http://www.austincc.edu/wkibbe/headdesign.htm

It's hard to find much good info on the internet on porting and polishing and there is a lot of misguided info and/or unproven ways to do things out there. With the right equipment and in the right hands I'm sure there is magic to had.

Here's an analogy. The cylinder head ports are like no man's land as the main battle takes place inside the combustion chamber. Your intake and exhaust are like the left and right flanks coming in and out and controlled by the camshaft which is like the Geneva convention giving you the rules to abide by. Just a thought!!!

(:-})

[tony.mon]

Thought this to be the appropriate place for this. I found an interesting article on cylinder head port/seat design.
http://www.austincc.edu/wkibbe/headdesign.htm

It's hard to find much good info on the internet on porting and polishing and there is a lot of misguided info and/or unproven ways to do things out there. With the right equipment and in the right hands I'm sure there is magic to had.

Here's an analogy. The cylinder head ports are like no man's land as the main battle takes place inside the combustion chamber. Your intake and exhaust are like the left and right flanks coming in and out and controlled by the camshaft which is like the Geneva convention giving you the rules to abide by. Just a thought!!!

(:-})

Mark GSLR has a set that I've committed genocide on, and I want to try to see how much power I've lost..... I chopped away a fair bit of the valve guide that protrudes into the cavity, with the intention of fitting new ones before fitting the heads.
But just for the hell of it, I quite fancy fitting them for a short while to see how much gain you get in terms of gasflow.
The shortened guides will wear in very short order, though, I would expect.

[Varastorm]

Looking into porting again, didn't realise it had been so long since last posting here.

Even the links to the cartridge rolls have disappeared

I nicked the idea of what tools to collect from this picture



I have just bought the gear for the job

Sealey 6mm collet 90° mini die grinder (eBay item number: 251451048870 ) £26 posted ✓



3M CARTRIDGE ROLL 12.7x38.1x3.18 P60 Grit 747D Bag of 100 80786 (eBay item number: 251825395509 ) £24.75 posted ✓

I know its a coarse p60 grit but I'll just have to be careful. BTW these 3M rolls are quite rare in the UK & this seller only has a few more bags left



3M CARTRIDGE ROLL MANDREL 1/8 X 1 X 6MM SHANK PACK OF FIVE 88749 (eBay item number: 390921572079 ) £10.96 posted ✓



Then I decided to buy this tube, to enable me to fabricate my own length of mandrel to get into awkward places.

The idea being braze the mandrel in one end of the pipe, cut the pipe to the required length you want & braze a 6mm bar/drill bit the other end for the die collet. Hopefully it will simulate the long mandrel in the top, uppermost picture

[8Ø x 1mm wall] 316 stainless steel seamless tubing 400mm length (eBay item number: 321635589432 ) £8.85 posted ✓



Wish me luck

[lloydie]

Good luck and remember don't remove to much

[Varastorm]

I have done a lot of reading about porting basics & how to (hopefully) get the most out of a VTR head.

I was thinking of using RCVTR's Porting pictures as a guide.

http://www.superhawkforum.com/forums/mo ... e-i-17262/





But have read this, also

Bob H's advice for porting:
From what I remember from Bob H's advice was just light port work/blending/matching was all that was suggested, but a 3-angle valve job was worth doing. If I can find the notes I made about his advice for porting I'll add it. He emphasized not overdoing it, gentle reshaping and matching inlet with carb outflow/spigots. I don't recall that he mentioned the exhaust ports at all: as for flowing the heads everything I've read indicates its as misleading as not done in isolation and without a lot of correlation with performance on the bike. its easy to go in the wrong direction: higher risks for not so clear gains short of a lot of trial/error/experience. Stock springs are fine with stage I or stock cams: they are cheap and replacing them seemed reasonable to me but probably overkill.

OK, I found the notes on advice for porting:
"Let me know when you have the codes, crankshaft, cases, and rods. For the street, the port work should focus on a few things. Do not make major changes to the port area; work on blending the bowls, slight flattening of the port floor around the short radius of each port, matching the carb manifold spigots, and to a good 3 angle valve job. The valve seats should be moved to the outer perimeter of the valves without going all the way to the edge. Total seat contact width should be about 50% of the overall face area."

Those pictures above don't look like minor work had been done.

Any help appreciated

[Varastorm]

Good luck and remember don't remove to much

Cheers Lloydie, I'll need it

[lloydie]

Mine look better than them !!!
For all your porting needs contact roger ditchfield .
He's very helpful and helped me greatly with mine and that's why I won't post a pic of mine .
He offers a head service at a very good price .

[Varastorm]

He's very helpful and helped me greatly with mine and that's why I won't post a pic of mine .

Out of interest Lloydie, did you do a before & after dyno run with just the head porting?

Just to see what's available just from porting the heads?

I do appreciate though whilst the heads are off lots of other mods are done & then it's hard to find out what mod has given what power gain

[Stephan]

Good luck and remember don't remove to much

Mine has reshaped ports with shortened valve guides on intake, so I hope it is not too much. I dont have pics, try to take some later.

Did you refresh 3 angles?

[lloydie]

He's very helpful and helped me greatly with mine and that's why I won't post a pic of mine .

Out of interest Lloydie, did you do a before & after dyno run with just the head porting?

Just to see what's available just from porting the heads?

I do appreciate though whilst the heads are off lots of other mods are done & then it's hard to find out what mod has given what power gain

No before Dyno runs tbh I've never seen this engine run !!!!

[lloydie]

Good luck and remember don't remove to much

Mine has reshaped ports with shortened valve guides on intake, so I hope it is not too much. I dont have pics, try to take some later.

Did you refresh 3 angles?

No just lapped the valves in as per manual .
I've built this engine on a shoe string budget sadly otherwise I would of just sent it to roger to be done .

[Stephan]

No just lapped the valves in as per manual .
I've built this engine on a shoe string budget sadly otherwise I would of just sent it to roger to be done .

Lucky man, today I paid for the oem parts from japan.webike, and cannot tell my budget is low But doing 3 angle valve job shouldn´t be much expensive.

[lloydie]

No just lapped the valves in as per manual .
I've built this engine on a shoe string budget sadly otherwise I would of just sent it to roger to be done .

Lucky man, today I paid for the oem parts from japan.webike, and cannot tell my budget is low But doing 3 angle valve job shouldn´t be much expensive.

Won't be long now then till you start building it

[Stephan]

still waiting for the pistons to be finished at CP factory, should be this week. So at least three weeks when it arrives and process through tax duty. I think I would be more lucky to order from Italy, than US ... :-)

[Varastorm]

I've built this engine on a shoe string budget

Where all in the same boat

To get the above bits I've promised not to get my fave Lidl cider for two weeks

The parts haven't even arrived yet & all I can think of is the Lidl freaking cider. Its hurting

Things we do, the only positive I can look foreword to is I might lose a bit of the belly & look less fat in my leathers