[glow=red,2,300]After pictures of a exhaust port that's been modified for street performance[/glow]
My Canon A1 took a turn for the worse and is being overhauled as we speak and will be out of commission for a month,so I'm using a Digiatl for the moment and I'm finding it difficult to capture quality shots with the new camera, so it's either rap this up now or wait,we're moving forward and if there are questions on a particular photo PM me.
This exhaust port is from the same head above,it's has had the stock guide shortened to my specs listed, the rough castings were first rough removed with a carbide cutter,then smoothed around the port with a 120grit abrasive roll,untill the port was plended to my satisfaction of my version of a street Hp port. If you'll notice where the bottom of the guide meets flush with the roof, the area around the outside of the guide could use alittle more detail but for street useage,this will be sufficient enough. The area in black marked A
Please take note as your looking at the port to the right, as how I started to profile the area around the guide and making it turn in relation to the turn. ON the exhaust,you want the flow on the roof,so blend this area carefully.Just look at the pictures.......
When you begin to profile the guide boss area,look at the pictures closely and remove alittle material at a time and work slow but be cautious in removing material when you start to feather this area around guide.The area in RED,marked B is the area that'll crack if to much is remove,when replacing guides and thats why it's important to proceed with shorting the guide first,then profile this area after the guide is reinstalled. Look at picture#5 carefully and take notice how i started feathering the guide by bringing the pointed tip pass the center of the guide looking from left to right,again this is to help assist air movement around to the turn of the roof and gain more cfm rating. Click the images
The final picture is of the shortside radious of the exhuast port and I might add this shot was the most difficult to take and is the only picture of the shortside detailing the profile and do to tightness of this area,your fingers will be doing the walking in this area,and i'll describe in further detail the process that I took to tackle this tight area and this'll be the final step to the exhaust porting,then I'll proceed on with the Intake. Jack
In the picture below,the black represents the shortside,the letters A & C are the corners of the shortside floor leading into the seat area and b represents the middle section of the shortside itself. If you'll take any hand and make a fist,then take your intex finger and extend it out to a 45 degree position and from the knuckle to the first joint is the floor section and at that first joint will represent the shortside turn and if you'll take and drag a finger along from the first knuckle and over the first joint,can you feel the smoothness of that area ,well that's exactly how you want the SS Turn to feel!! no rough edges,just a smooth transition from the floor leading into the seat area. The ways I found to smooth this area was to take a 120 grit abrasive roll and extend into the port area to where the radios is ([glow=red,2,300]you must use a long reach cardrige roll mandrell to achieve this result)[/glow]or other wise it'll be difficult to proceed with this step but another solution is to take long strips of emry cloth and work this area by pulling on both ends of the emry cloth untill you get a smooth SS radious and I might add it's a slow process but it's a necessary step. Take your time and" Good Luck " Jack
These two pictures clearly show the differance in the casting thickness of the exhaust ports and they're some ports with worse inconsistent casting thickness than this,so be prepaired to work with what you've got.
The bottom picture is my roughed in roof section with the short guide and with some extremly extensive work in the pocket area of the seat,that extends out the port and these mods will be kept secretive for awhile.
Thank you for posting all of this Jack. Your picture taking skills have improved a lot. All of these pictures look great to me. They clearly show exactly what needs to be done during the porting process. Thanks again.
[glow=red,2,300]"Polishing" The Final Added Touch[/glow]
Once all the heavy cutting of removing the casting flaws and imperfections in the ports with the carbide cutters or cartridge rolls, you can now polish the exhaust ports using various combinations like sanding attachments ,flap wheels and cartridge rolls of fine grits. Generally polishing is a step that uncovers minor surface irregularities,bumps,ripples and dips that are extremely hard to see but are alway present in the porting process and it's been proven that additional CFMs can be achieved through surface refinishing or polishing the ports. The steps I took to polish the exhaust ports are 1) After the ports were in the final port stages I used a 120 grit roll to start the polishing process
2) I used a 220 grit wettable sand paper torn in strips,then folded in half to provide better stability in the forward and backward motions when using the finger grinding process. (wet the paper)
3) Then I repeated the same step but with 400 grit paper.
4) I then cut a coat hanger and folded over a section at the end to provide a grip for holding the strips of scott brite to gain a smoother surface. I used the medium and smooth grits for this step.This where the 3/8 drill comes into to play
5) Finally,I used "Mothers" polish and this would be an option being it'll have no effect on performance. Once you fire it up the shine disappears. All your looking for is a very smooth surface to avoid fast carbon build up but in the end it'll eventually build up with carbon.
[glow=red,2,300] Pocket porting the Intake[/glow] It's my opinion that the intake port construction of the XS isn't that bad in regards in searching for that little extra punch we all seek. I was able to unleash on an average of 25 extra cfm to max lift of 480. When you combine a well thought out engine package,I have no doubts that a XS 650 well tuned should in my opinion knock out atleast or close to 60 rear Hp.
The Intake is probably as straight forward as they come in regards to simplicity in porting. There are a few pictures that'll be upgraded later on but for now I hope these will do it.
The picture below is just to illustrate a close up of the port casting flaws from the machining process and they were crude indeed. And it's important to remember,that not all heads share the same casting flaws as in the pocket area,the shortside radious and the floor.
The methods of which I removed the casting flaws was to use a carbide cutter to remove all flaws on the floor, sides of the port runners,roof, guide boss area and the pocket itself. Then after all were remove,I moved in with the 36 grit cartridge rolls to blend in all area and for the final finish. It's important when dealing with aluminum to have the correct boundry layer finish to help create just a bit of resistence to allow for fuel droplets that fall out of suspension to be able to return to the main airstream for proper fuel automation mixture. And a 36 grit surface finish fits the bill in my opinion and the is only grit I use on aluminum intake ports.
Remember to go slow,use a low RPM for cutting and remove alittle at a time untill you familiarize yourself with the porting process and to develope your own style of "Technique" in porting.............Jack
Now the fun begins again ::)When looking at this piture,you can go to the picture below for a close up of the pocket area and the flaws. The letter "A" is the area from where the steel cap meets the aluminum and is the area thats generally smooth to where it meets the roof casting " B". When porting this area,you must try to avoid digging deeper OR gouge where the cap meets the aluminum as it could disrupt the flow but even I'm not perfect,so take it slow.Use your finger and drag it along this area and the whole port for that fact,to judge your process and to make corrections if needed. From letter"B" you want to remove this rough casting in equal amounts to the guide area and around the back side of the guide. And again I found it much simpler to remove the guide to work this area in greater depth.The black arrows are the points where the roughness begins,the red is the direction in which you must remove thr material.
Again "PLEASE" read the whole post text before proceeding on to porting to better get a grasp on the process of which I used or to develope your method........ Jack
THe first picture is just a blow up of guide boss section
In the picture below are the letters "A ,B & C" The letter A is the area of which you'll gain CFMs but you must caution in the amount a material to remove being this is in the roof section and the area above does'nt have much to offer to remove due to the spring cup area being thin. But most important you need material in the area to support the guide and I 've been there,so use your judgement here.
Letter " B" is the area around the guide, try and work this area the best you can. If you leave the guide in,you'll need small diameter cartridge rolls to work this section.
The letter 'C" is the guide itself and there's CFM lurking in front of the baby,so you either trim it down using a carbide cutter,then smooth with a 36 grit cartridge roll or take meassurements to where the guide meets the roof section,knock it out and trim the guide in a lathe for a cleaner look..... Jack
In this picture,it just shows the rough casting flaws of the port wall OR runner and the short side radious turn
The letter" A" is the wall and you find alot of dips and uneveness ,rough castings( remove the rough casting with cutters first then roll it) But what's not seen,is the area of a hugh dip from the casting foundry,near the section where the studs go for the cylinders and heads. Run your finger along this area,then you'll see what I'm talking about.
The letter "B" is the shortside radious and this will require a soft touch to profile as to avoid removing enormous amounts here but just blend it smoothly from the floor leading down to the seat. This is the area in which air speeds up or down or to match to the cam lift to maximize full performance for a particular lift.
I would like to say that the floor leading into the shotside radious ,is the area in the XS head where you'll notice alot of casting flaws such as,floor thickness and formation of the SS Radious . I 've got a few heads where there's sections of the cap exposed and all you can do is blend this the best you can and move forward.......Jack
r80rt: :)This is a splendid write up, THANK YOU!!!!
Dec 26, 2015 16:54:05 GMT -5
mashermoto: What the what is this shoutbox for? Or should I shout, WHAT THE WHAT IS THIS SHOUTBOX FOR!
May 12, 2016 22:22:21 GMT -5
motormike: Good Day ...just a FYI.. Wild Cat is this Labor Day weekend. Still go'n on. A few 650's still make the scene. Various rides at different skill levels each day.. awards dinner sunday eve. BS in the park'n lot after dinner.
Aug 23, 2016 7:57:01 GMT -5
lsettle: First post in over 6 years!
Aug 28, 2016 19:45:17 GMT -5
kardon: Wow quiet here, where did they all go.
Oct 7, 2016 2:18:13 GMT -5
gggGary: XS650.com LOL
Feb 16, 2017 20:49:02 GMT -5
buell88: Anybody have any idea who built the xs650 tracker used in the Draggin Jeans Ad on Pipeburn?
May 16, 2017 16:24:09 GMT -5
joshua: The regulator/rectifier unit I got from Mikes PMA has closer hole spacing than original. Are we supposed to mill the holes to fit?
Jun 7, 2017 19:25:58 GMT -5
joshua: My bad. I found the bracket they supplied to mount the rectifier/regulator... Uh oh. How is this meant to work? Which way is it meant to mount? Looks like I have to use some spacers or something. Good instructions would be nice.
Jun 7, 2017 22:09:52 GMT -5
craig8johnson: Not sure if this is the right spot or not but oh well...
Jul 11, 2017 18:04:15 GMT -5
craig8johnson: I'm checking the charging system. I'm afraid I might have fried the last battery. With the solid state regulator (after market) what should it be charging at. The book says, I think, 15 volts. I'm hitting 17 when revved. Is that too high?
Jul 11, 2017 18:06:19 GMT -5
gggGary: Yes 17 volts is too high, about 14 volts is max, sounds like you don't have the right regulator or it's wired wrong.
Jul 13, 2017 6:54:33 GMT -5
dean: Just saying Hello, new member who is going to fix up a 79 XS650 that has seen its better days. I will definitely have lots of questions coming up.
Jun 23, 2018 16:45:32 GMT -5
tt650: Trying to breathe life into a 1980 that's been stored (indoors) for 25 yrs. Air filters are dry rotted. Have cleaned carbs but she only runs briefly on choke then stops. Need jet setting info and other ideas that might help her idle and rev.
Jul 3, 2018 19:15:19 GMT -5
trix13: Hey everyone! New to the forum and am fighting those gremlins!! New charging system, ignition switch, coil and fuse box. Resistance is higher than normal on the ignition pick up so I'm trying to find one. No such luck yet.
Aug 16, 2018 8:50:48 GMT -5
trix13: Also, even though all of my connections are clean, I cannot seem to find out why , when at higher rpms, I hit the signals and the rpms pulse with the signals...hahah. same with the brake light. I appreciate all input!!
Aug 16, 2018 8:55:08 GMT -5
bob99: how do I post a question. I am new to the forum
Jun 6, 2019 10:52:10 GMT -5
adlpc: Hello all! Been enjoying your edifying posts and discussions - and as a fan of the XS650 since my early teenage years happy that I now own a 1980 Special which I plan to turn into a vintage half faired racer. Thank you all for being here!
Oct 1, 2019 0:58:56 GMT -5
jimothyj: Hello everyone, I just joined & wish would have known about this site in 2014 when I brought my 1974 TX650A back from the grave. I have spent a good deal of $$ and alot of time on it. Just painted it and working on electrical, I will post pics soon,
Apr 10, 2021 2:14:13 GMT -5
louisvan: trix13 - I had a problem with my 1975 SX650. When I got to highway speeds, the engine lost power. The problem was in the connectors. At a certain vibration and the wind pushing on the wiring loom, the connector lost continuity. A bad crimp to the wire.
May 20, 2021 1:19:09 GMT -5