Port & Polish your piston liner

[g1tana]

Got this engine in the savage this weekend noticed great improvement straight seems to have increased RPM and powerband is there from the off.
We lost the temp gun whilst we were out so tuning was done by smoke and touching the head and a good old fashioned bit of spit too. Lol
So always able to put palm on head for 3 seconds or more and spit never boiling but evaporating quickly but gradually and plent of smoke and thinin out nicely at full throttle.
I did however go through 3 plugs in 4 tanks and need to find the right plug.

I changed the gearing since the last time I ran my savage and I think I over geared it(not really giving engine chance to really shine) I'm gonna put it back to how it was and get a proper idea of the differences.

Really pleased with haruns work modding this engine will be sending more engines for modding

[modder]

Picco Max 26

Before...





After...

[modder]

Ninja MR21 R01 standard before pics...






I had cleaned this liner a half gallon ago, it was black and most of the ports were gummed up with carbon.

It had a lot of Sharp edges and lacked detail on port work. So I introduced liner to my friend Mr. Dremel...






I'm due to run this later today and astray from my usual I will post feedback on this one. Running in an Evolva 2003. Bought this one used, liner has damage from a dropped plug but runs nonetheless. Compression is minimal.

[modder]

Quick update on the runs after mods.

Fired her up, immediately top and bottom needles were rich. After dialling in the top and bottom end a few minutes engine began to clear out. Noticeable Power increase throughout rev range.

Bottom end is quite weak on this mill with the JP Pipe I’m using and medium header. However it now appears to be punchier on the bottom and revs up more aggressively.

Run times are also up a bit.

Tried and tested - Port & Polish improves flow into ports, if done correctly will show signs of improvement. There are few sceptics that I know of and talk with on the subject of purely porting and polishing.

Quote:
"Doesn't always work! I tried it x engine and it worked then I tried it on another and noticed nothing"

If you look at the sleeve with a specific mind-set you can visualise certain occurances. For instance air flow. Air likes to travel over smooth straight surfaces. If you liner ports have sharp edges it will cause turbulence and slow down the flow of air.

Turbulence is good. It aids the mixing of fuel and air but this predominantly takes place in the crank and at the edges of the ports (the very inner edges). The sleeve surfaces do not in my opinion benefit from any sharp edges.

I am currently working on port timing so watch this space.

All input, comments and suggestion are always welcome.

What have you done? Why? How? tools, burrs and attachments etc..

[Cartman]

whats you thoughts on the fluid movement over smooth polished surfaces or non polished, bearing in mind that a racing yatch, power boat will not have a polished surface as the water then sticks causing dray, they use a sanded surface to create turbulence/bubbles which makes the hull go over the water faster?

[modder]

Hello Cartman,

Sorry been a while since my visit to this post. The way I see it are water and a mixture of air and fuel have rather differently due their densities. Nonetheless both can bead on a smooth surface. From my observation and reasearch I have found a balance of smooth and deliberated rough surfaces. The crank inner surface is designed in the way you mentioned about boat hulls, to promote turbulance and aid in mixng the air and fuel. When this mix reaches the end of a crank scoop it is forced out and some of which travels up the liner outer and case inner. The case inners are generally also rough from casting,turbulance and again when the mixture is sucked through each port it again encounters turbulance from the inner sharp edges of the port. So although you don't gain a massive increase from port and polish by having a smoother surface on the journey up the liner walls it is aid ing efficiency of the whole process of filling the chamber with mixture. On my p&p jobs I always end up leaning the top end considerably. Somewhat indicative of an increased efficiency due the aforementioned cycle. Having a smoother liner surface promotes more of the mixture to take this path.

This is my interpretation, I am by no means and expert in any of these fields but have an inventitive, analytical view on processes.


Thanks

Modder

[MrWolf811]

Hello again,
If you have some time I want too send an engine your way.

[kyoshoV1RR]

LRP 30 Xtec

Before any before and after pics I want to say a few words and take my hat off to the guys at LRP. This engine is a monster. I love the attention to intricate details that have been employed on this mill. The crank is amazing and couldn't be improved much if any at all. Coupled with a 5port liner and a great crank case and exhaust porting design I can see how this unit makes 4hp with ease.

Before pics...






After...

Please do not have this guy do mod work for you. View all pics closely, every engine he mods looks pretty but look past the fang cuts into the ports and what do you see? A marde up sleeve liner a good engine mod should not have scrathes or marks on the inner sleeves liner, this is bad and he will murder you engine.

[kyoshoV1RR]

Please do not have this guy do mod work for you. View all pics closely, every engine he mods looks pretty but look past the fang cuts into the ports and what do you see? A marde up sleeve liner a good engine mod should not have scrathes or marks on the inner sleeves liner, this is bad and he will murder you engine.

[wreckers]

kyoshoV1RR have you had an liner done by modder? your clearly just going by pictures stop being a keyboard warrior an stand behind your words, get a liner done.

Seen the work first hand, seen engines run before an after mod work an stripped down with no damage to liner nor piston.