Have a lathe?

[crazykart]

Anyone in the U.S. have a lathe and drill press and maybe want to make me some adapters?

I have some atv rims/tires that I would love to use, but one set is 4 on 4.25" (108mm) and the other set is 4 on 4 3/8 (111mm if I'm right) and I need them to fit on 4 on 4" hubs...

I figures maybe someone could do it cheaper than it would cost for new rims.

Plus I really don't feel like redrilling the holes lol. No drill press at home, and work won't let me use theirs for personal projects.

I'm still hunting for a machine shop close to me, but so far the only ones near me only handle "big" clients...

Have fun on a lathe and make a few bucks maybe? just a thought.

Or maybe we could trade? I have some extra tires, rims, a 5.5hp briggs intek with low hours, or even my spare ps3 (though for that I might want more than just adapters.

 

[BirdFanatic]

I was wondering if anyone is able to do a little porting and polishing for me .Maybe mill the head a few cc

 

[crazykart]

Porting and polishing is easy, get a dremmel (rotary tool) and Google how to. You would be suprised how easy it is. Now milling the head is a different story.

 

[landuse]

There are a few people on the forum that might help you out

 

[BirdFanatic]

Porting and polishing is easy, get a dremmel (rotary tool) and Google how to. You would be suprised how easy it is. Now milling the head is a different story.

My father told me to study the same book he read it was 219 pages about arrow dinnamics and flow in an engine before i even begin he said i also need to know what has been done o the motor in able to port and polish the right way .(why go through all the trouble to do it myself when you can make things easier by paying someone to do it and tell them what has been done to the motor to give them an idea .

 

[crazykart]

To each their own I guess. The basic things to know though is that porting an intake increases airflow. Polishing decreases turbulence which leads to improved airflow, and if you're going to port and polish for airflow then you're going to have to increase fuel flow/volumn in some way to keep up with the added demand for it.

Trying to increase compression is a different beast. It can be helpful or harmful and really all depends on the current compression, and tel he peak compression that the engine will run at. Skew the numbers too much and you can do more harm then good. Maybe even to the.point of creating a no start/non running condition.

A few mm though should be fine, depending on the size of the engine, but one smaller engines you really want to watch out for piston contact.

 

[BirdFanatic]

To each their own I guess. The basic things to know though is that porting an intake increases airflow. Polishing decreases turbulence which leads to improved airflow, and if you're going to port and polish for airflow then you're going to have to increase fuel flow/volumn in some way to keep up with the added demand for it.

Trying to increase compression is a different beast. It can be helpful or harmful and really all depends on the current compression, and tel he peak compression that the engine will run at. Skew the numbers too much and you can do more harm then good. Maybe even to the.point of creating a no start/non running condition.

A few mm though should be fine, depending on the size of the engine, but one smaller engines you really want to watch out for piston contact.

my current yy250t (Scooter) has about a 7.1 ratio and could be harmful if i make it any higher .Increase that is needed for fuel can easily be met by changing jets

 

[crazykart]

Ya I wouldn't push passed that 7:1. If you can calculate the increase in air intake it shouldnt be a problem then. The main good thing about porting and polishing though is the decrease in turbulance for the air intake. Less turbulance= better air/fuel mixture, better combustion, less wasted gas in the burn. If you're doing a small engine then there is a good chance you could get an increase in efficency of around 20% if not better. Change out the jets, and increase the compression a bit and you might see upwards of a 40% boost in both efficency and power output. Thats best case, but honestly even with a 20% total increase on efficency and power I'm sure you would be happy.

 

[Btchin86]

You don't EVER polish the intake track, you want to leave a slightly rough or grainy surface. Fuel suspended in the air will stick to the smooth surface instead of bouncing around and mixing with the air more. On the exhaust port you want to polish it to help the exhaust flow better.

 

[Btchin86]

To the op, you might try to find some for cars that will have the right pattern, shouldn't be all that expensive. I'm not sure if you will find some but it would be worth a look

 

[Desertduler]

You don't EVER polish the intake track, you want to leave a slightly rough or grainy surface. Fuel suspended in the air will stick to the smooth surface instead of bouncing around and mixing with the air more. On the exhaust port you want to polish it to help the exhaust flow better.

 

[crazykart]

No, not FULLY polish it, but you also don't want to leave it so rough after porting it. You don't want a shiny surface, but you also don't want it overly rough either because that equals turbulance. Doing car intakes, high performance engines we would "polish" to between 80-120 grit with sandpaper. Yes I should have phrased it correctly as that could lead to.some confusion.

You also want the grain to go "vertically" with the intake hole so that the air flows through the grooves. You can do horizontally, but the air hits the grooves and causes turbulance. The unspent fuel will also have a chance to run down the vertical grooves, where as the horizontal grooves it will just sit in. Now for small engines you might only want to polish to between 60-80 grit at best.

Usually to port though we would use a steel cutting bit on a dremmel, or flex shaft off of a drill. That steel cutting bit tends to leave the surface very rough, actually about as rough as the original casting would have been. That's where the polishing comes from. You want the majority of the roughness knocked down. Air hitting a rough patch causes it to "bounce back/around" which causes less air to be drawn into the engine. Air that can free flow without obstruction equals more air in the engine, and non turbulent air creates a better environment for the atomized fuel to stay atomized instead of clumping back together.

Sorry if there was confusion there.

Btchin86: I've thought about vehicle adapters/spacers, but first I would rather take the diy route, and give someone a chance to have fun on a lathe/make some quick cash, or something they may need for their build. Though it's not me diying, I really like the whole appeal of having most of my parts custom. I've even toyed with the idea of making my own hubs.

 

[BirdFanatic]

Ya I wouldn't push passed that 7:1. If you can calculate the increase in air intake it shouldnt be a problem then. The main good thing about porting and polishing though is the decrease in turbulance for the air intake. Less turbulance= better air/fuel mixture, better combustion, less wasted gas in the burn. If you're doing a small engine then there is a good chance you could get an increase in efficency of around 20% if not better. Change out the jets, and increase the compression a bit and you might see upwards of a 40% boost in both efficency and power output. Thats best case, but honestly even with a 20% total increase on efficency and power I'm sure you would be happy.

i all ready get 75 mpg so maybe ill find a thin gasket or make my own and smack it with a hammer a couple of times lol to thin it out . Wonder if someone on her is able to do a good job with it if i send them the head and a price . Nvm about the 7:1 this site says 10.3:1 another said 10.1 another said 7:1 ratio so im going to go in the middle because these are china made id say 8:1-9:1

 

[chancer]

So... Does anybody want to help him with a lathe to make those hubs work?:::

 

[crazykart]

Lmao, I almost forgot my own topic. Ty chancer.

 

[crazykart]

Well guessing its a no. Time for plan B- drill new stud holes in the rims.

 

[Desertduler]

Porting and polishing is easy, get a dremmel (rotary tool) and Google how to. You would be suprised how easy it is. Now milling the head is a different story.

Porting and polishing is not easy, You had better know what you are doing if you are going to attempt such a task, just because a port looks better and bigger and so on that does not mean that it flows better, there are too many things to understand that any novice so called port expert needs to know before they try to make a engine run better. Many things! If I was not so busy I would help you out with your adapters.

 

[Desertduler]

I was wondering if anyone is able to do a little porting and polishing for me .Maybe mill the head a few cc

If you can wait until the fall I could port your cylinder head for you if indeed you are serious. Milling your cylinder head would not be a good idea due to the fact that your engine is a OHC configuration and when you reduce the distance of the camshaft to the crankshaft the camshaft timing becomes retarded because the timing chain will wind up being longer because of the distance change between them. But there are ways to correct that if you know what you are doing.

 

[Poboy kartman]

Porting and polishing is not easy, You had better know what you are doing if you are going to attempt such a task, just because a port looks better and bigger and so on that does not mean that it flows better, there are too many things to understand that any novice so called port expert needs to know before they try to make a engine run better. Many things! If I was not so busy I would help you out with your adapters.

Yes and no.....it's true that it's just as likely to do more harm than good attempting a port and polish job without the proper knowledge.....and there is much more to it than meets the eye.......

A couple of things....small single cylinder 4 stroke engines aren't that paticular about precision porting...you can't change a whole lot of aerodynamics in one inch.....8 cylinders with 3 1/2" of twisty turny ports....a little different story....

Also.....While it takes a huge amount of knowledge to alter a port correctly.....you don't necessarily need that knowledge....you just have to be able to follow directions and copy what someone who knows tells you to do step by step on the internet.....

 

[OzFab]

Again,

Well guessing its a no. Time for plan B- drill new stud holes in the rims.

The other option is to redrill the hubs to suit the rims...