Cylinder head porting?

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lloydie
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Location: In the garage somewhere in Coventry

Re: Cylinder head porting?

Post by lloydie » Thu Feb 12, 2015 10:17 am

Varastorm wrote:
lloydie wrote: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 :cry:

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 :roll: :lol: :lol:
Get yourself some cider and bigger leathers and stop torturing yourself :-)

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Varastorm
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Re: Cylinder head porting?

Post by Varastorm » Thu Feb 12, 2015 10:34 am

Been reading some more & read about Tallow Grease.

It's to be used with the cartridge rolls, not too sure how but will find out before the end of the day I am sure :D
For the best results use with Tallow Grease abrasive lubrication.
Tallow Grease extends the life of your rolls by reducing heat, dust and harsh cutting,
while providing a smoother more uniform finish, making it much easier to buff out.
I read this & it sounded like he was on to something.
I pay a lot more attention to cross section and port shape than how I finish a port. If I'm gonna sand it out 60 grit on the intake port. If you want the cartridge roll to last use some wd40 . It will keep the dust down some. When the 60 grit get worn down some I use them on exhaust. There is nothing wrong with a burr finish if you do it right.
Then this guy.
I know air flow is all in the shape, not the smoothness of the metal. I just was curious how smooth you guys like to finish your stuff.
I also use tallow grease on my sanding rolls, much more uniform finish and last longer than using cutting fluid or wd-40.
Right, Tallow grease none on eBay :think:

Have to go for a look in the local DIY shop & ask some questions :thumbup:

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Varastorm
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Re: Cylinder head porting?

Post by Varastorm » Thu Feb 12, 2015 10:39 am

lloydie wrote:Get yourself some cider and bigger leathers and stop torturing yourself :-)
I have been doing that for years :lol: :lol: :lol:

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Last edited by Varastorm on Thu Feb 12, 2015 11:05 am, edited 2 times in total.

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Varastorm
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Re: Cylinder head porting?

Post by Varastorm » Thu Feb 12, 2015 10:44 am

I thought this was a good example/analogy of fluid dynamics :thumbup:
Why Not Polish The Ports ??
Doesn't Air Flow Better on a Smooth Surface ???

Remember that the ultimate goal isn't "flow" ... it's POWER !!

The intake port is going to flow both fuel and air. The problem with fuel is that, since it weighs more, it's difficult to keep it evenly mixed with the air as it follows the contours of the port.

Boundary Layer

The next time you drive a car in the rain, notice that when the car is going 60 MPH, the rain drops go up the hood of the car at walking speed. That's because the smooth surface of the car creates what's known as a boundary layer, and the portion of that layer of air that's nearest to the surface is almost still.

The same thing happens inside an intake port. Except instead of raindrops, it's fuel droplets that will run down the port wall slower than the air. That causes a serious change in the fuel air mixture by the time it reaches the cylinder, ruining much of the engine's potential power.
Polishing the port walls will ensure that this happens.

The phrase "Port & Polish" always makes me laugh ... I think the idea came from 70's Hot Rod magazines or something. Anyways, the last thing you want to do is polish your ports !!!

Instead, by making a series of rough 60 grit lines that purposely go against the flow, the "boundary layer area" will be turbulent, and the fuel will stay suspended in the air.

Remember: Rough is Good !!

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VTRDark
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Re: Cylinder head porting?

Post by VTRDark » Thu Feb 12, 2015 1:28 pm

There's a reason golf balls have dimples. :thumbup:

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Varastorm
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Re: Cylinder head porting?

Post by Varastorm » Thu Feb 12, 2015 8:28 pm

Been looking for Tallow grease :roll:

It looks like its just beef dripping :lol: :lol: :lol:

https://en.wikipedia.org/wiki/Tallow

You learn something new every day :D

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VTRDark
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Re: Cylinder head porting?

Post by VTRDark » Thu Feb 12, 2015 9:09 pm

:lol: :lol:

That shouldn't be too hard to sauce then. :plainsmile

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Varastorm
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Re: Cylinder head porting?

Post by Varastorm » Thu Feb 12, 2015 9:39 pm

Been looking on eBay, zilch :problem:

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VTRDark
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Re: Cylinder head porting?

Post by VTRDark » Thu Feb 12, 2015 9:46 pm

A farmers market may be better :lol: Or maybe you could just have some roast beef this weekend. You can buy dripping in the supermarkets.

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Varastorm
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Re: Cylinder head porting?

Post by Varastorm » Thu Feb 12, 2015 10:42 pm

cybercarl wrote:You can buy dripping in the supermarkets.
I was joking :roll: :lol: :lol: :lol:

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VTRDark
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Re: Cylinder head porting?

Post by VTRDark » Thu Feb 12, 2015 10:49 pm

That will teach me for not reading the Wikilink :Ball Kick: :lol:

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