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How It's Done - Projects around the Shop

423K views 674 replies 47 participants last post by  ericdonalddavenport 
#1 · (Edited)
Billy & I have decided to start an on going thread called “How it’s Done”. This will be an informative and educational thread to show how things are done in the Machine Shop.

After being a member of this most wonderful site, I’ve noticed ads & recommendations to many other shops that do custom work. I’ve noticed that most of the time you are led to believe the other facilities manufacture their own products. Fact is, this is seldom true. The custom cylinders come from www.CPindinc.com, the sleeves come from either www.nwsleeve.com or www.lasleeve.com. This kind of work is seldom done by your local engine builder, it’s far beyond their capabilities.

This isn’t a competition on who knows the most or the best or any of that stuff. We hope that any of you will reply with comments, questions & criticism on anything which you see in the thread. Billy will do a monthly recap or something depending on how things go with our endeavors. I expect to do a weekly addition to the thread. Subjects will be random depending on the projects that come across my work bench.


Index

1. Measuring tools
2. Cylinder boring prep., Hone introduction
3. Hones cont. Sleeve preparation & comments
4. How strong is that piston, Sleeves & cylinder etching
5. Boring & Sleeving A Mercury V-6
6. Boring & Honing, 2-stroke ideas, That mighty old Dale Herbrandson Reed Valve. DH Reed valves started everything in the
reed valve business.
7. Sleeving LT250R cylinder, Bore & hone a Yamaha twin.
8. Mandrels, coils, some handy information.
9. Stainless steel head studs, Foundry patterns for new cylinder liners.
10. Replace main bearing support bushings.
12. CR500 compression releases + or -
15. CR500 Liner replacement
16.-18. General discusion
19. Your Sleeve shrink fit, Sleeve foundry patterns.

37. Check your squish/deck height
40. Main bearing inserts the CNC way, How to figure your Squish Band.
41. Sleeving LT250R, Some coil inserts, Torque plates.
42. Sleeving 350 Yamaha, Replacing stripped exhaust threads.
43. Montessa Reed valve, Old time water coolers.

48. KX500 Sleeve instalation
51. Compression calculations
51. Sleeve Weber
54. Sleeve 650 Triumph twin



40 years & still moving along.

New Cylinder boring bar stand.

My background is a lifetime in the Machine Shop. I’m now 65 and started boring cylinders some 45 years ago. As you all have probably noticed from some of my comments, I also have a lot to learn. We all must humble ourselves and learn something new each day. Please chime in when you have some good ideas to share with the readership. Most of your replies to my stumbling comments have been polite and constructive. Please keep a positive attitude with your replies and it should all be worth our efforts.

Since I’ve become a member of E2S, I’m starting to see a lot of the JUNK work which others have paid a lot of money, only to end up in disappointment. I’d like to show and explain how things would be done from the “Old Dog” perspective. No Jetting, Timing, Pipes or Dyno tuning. That’s for the rest of you folks who know about that kind of stuff, Jump in.


Measuring tools: This is an example of some of the Junk which floats around and the tools used to help avoid some of the problems.



A dial or digital caliper is an economical and handy measuring tool. When some close measurements are required, you need to step up to a micrometer and dial gauges.






A 250cc cylinder converted into a maximum Big Bore engine. The bore is so large that there is no Head Gasket surface left. Common sense would tell us that this isn’t a good idea.




Sometimes a sleeve needs to be mounted on a Mandrel in order to get accurate measurements for calculating the Squeeze fit.



The Dial Bore Gauge is the work horse in the bore measuring department. A little spendy, but well worth the investment. When you farm out your cylinder machine work, you can check up on what your engine guy is really doing.




Measurements on the lathe. Over time, you’ll get a Feel for your tools.
A minimal invest in precision measuring tools is a fine addition to your tool chest.

We're new at this, Fire away with your questions.

“Old Dog” www.smallenginemachineworks.com
JT
I've worked on the layout of this thread all Morning. I GIVE UP.
 
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10
#59 ·
What to do next

I’ve been showing you readers Machine Shop processes which are informative and interesting. How it’s done in the Machine Shop is a very repetitive thing over time. There may not be an article each week since there isn’t something different to talk about every week. Whenever any of you have questions or Ideas please chime in.
I’ve been working on reviving some of the DH Reed valve porting techniques. I now understand why Dale used to grumble when we’d ask him for another drill jig. The darn things are extremely difficult to accurately produce. I’ve been working on a jig for the vintage McCulloch Kart engines. After the 3rd. try it should be done next week.



I’m eager to use DH Type boost porting in some of the newer water cooled cylinders. Any way to improve the piston support on the intake side without hindering performance would be a plus. For any of you who are interested, we will do a feature write up on your cylinder for a new sleeve in E2S at a discount.
Over the years many things have changed on the 2-stroke and many things have stayed the same. I found on the net a great book “Two-Stroke Performance Tuning” A. Graham Bell. My used book was probably only thumbed through, it’s just like new.




This book is a good read though there might be many questions still unanswered by the time you finish up. Pipe construction is well covered. You quality pipe builders really have a challenge getting your Pride & Joy design to fit in any frame that comes along.
Later
“Old Dog”
JT
:thumbsup:
 
#60 ·
That is one of my favorite books about 2-strokes John. A TON of great information in there and it covers all spectrums. A lot of things in there mentioned that most people do not consider or think of often as well I think.
 
#62 ·
Reline / Sleeve RM250 Cylinder

We have 2 RM250 cylinders to reline this week. I’m doing 1 at a time to continue with my column in a timely manner.
The power valve popped out just fine, it’s far enough away from the exhaust port so not to cause any fit problems.
A quick note, I drilled another hole in my torque bar so it would fit the cylinder. With the odd ball and delicate shapes of the cylinders produced now-days, you need a torque bar for every cylinder that you are working on.


Simple to make from material in your scrap bucket.


Stud holes 12,10, & 4 are good and solid. 6 snapped off, 2
& 7 are pulling out and need Heli-Coil type inserts to repair the Head bolts. This kind of problem causes your machinist much extra work raising the cost of the repairs.


Good Stud pullers are a fine addition to your tool box.


Another little Bugger that can be difficult to pull. A drill bit or transfer punch works well to grip the thing.



The cylinder is counter bored on the lathe instead of the Boring Bar. The boring bar is a little light weight to be taking heavy cuts.


I like a good platform and flange width on the new cylinder liner. A good fat flange guarantees that the liner will never drop.



The new liner is bored inside and out on my trusty old Andrychowski Polish Lathe. I purchased this machine new in 1976 for $5,600.00, and thought my father was going to Crapp His Pants. Many years later and it still machines accurately enough that I don’t need to grind the finish OD’s.
Notice the Dial indicator on the cross slide.

After the blank liner is finished to size, the cylinder is heated to 500 deg. The parts are put together for the Acid etch process.

In this view, the hot cylinder (SPIT HOT) is lowered into the Acid solution and allowed to Cook for around 5 minutes.




VOILA No Secret, just Knowledge.


Sometimes the Port Grinding man gets a little carried away with the port widths. If the bottom rear hadn’t broken away, this area would probably have been next. The new liner is around 4mm thick which should take care of this weak area.



Next time we’ll accurately cut and measure all of the port heights. I’m studying the book “Two-Stroke Performance Tuning”, (A. Graham Bell). This book is a handy reference for what may and may not be done with the new liner port timing. It’s time to contact the owner and find out what kind of power he expects to get with his repair job.

Your comments & suggestions are more than welcome.

Next Time
"Old Dog"
JT
 
#67 ·
Keep it up Mr.Tice :thumbsup:
I see your reading the 2 stroke tuners handbook. I have a well used old bootleg copy.
I used the book to make a pipe- well add a silencer to a pipe for my R/C car.
It's called an internal stinger pipe. I highly recommend the members pick up a copy and read read read!
There is so much useful info in the book.
If you feel this is intruding on your thread just say the word and I'll remove the pics buddy.








 
#69 · (Edited)
That precise piston diameter

I just finished up a bore job on an old early 70’s R5 piston port 350 Yamaha. The pistons came from HVC Cycle in Nebraska. Give them a call if you ever need some old Vintage parts.



This set is one of the few 2-stroke Japanese cylinders which appears to have removable liners. I think I’ll have a set to repair and reline soon.

My thoughts came up about how to accurately measure piston sizes when doing a bore job. With all of the different suppliers and brands it’s tricky to figure out where to measure the largest diameter.



Some pistons have a mild taper, some have a belly in the center and some a fairly straight.

What works for me: While finish honing the cylinder, I stop at around .0015” clearance and rinse things off. The fine hone filings are enough to jamb up the new piston.





While stroking the piston up & down in the bore, a certain resistance will be felt. It probably would be good to paint the pistons with Dykem layout dye, but I didn’t on this project. After a short time you will see the largest diameter point from the wear marks. Each piston needs to be measured since production runs may vary in diameter tolerance. Sometimes you’ll find the largest diameter isn't where you expected it to be. When the dial gauge is set you’ll have the correct dimensions to fit the parts accurately. That final skirt clearance fit is one of the most critical measurements in your engine.



Just got his photo from a happy customer in North Carolina.



Wash your Hands
"Old Dog"
JT
:thumbsup:


4-8-13
I just bored another CR500 cylinder yesterday. The cylinders have such large intake ports that they are nearly impossible to do a precise hone job. The one I just did has a .001” bulge in the center. It will run fine but I’d prefer to be more accurate. When a CR500 cylinder has a new sleeve installed, it must have a couple more ribs inserted in the intake area to properly support the cylinder hone.
 
#71 · (Edited)
That Wonderful Cast Iron

Cylinder liner composition: The heart of every internal combustion engine is the cylinder, piston & crankshaft. It’s Kinda hard to know everything so I’ve most always concentrated on cylinders. I like to call the (Sleeve a Liner) as many people call the Engine a Motor. 2-Stroke porting is the specialty that everyone seems to gravitate to, have at it Guys.

Basically all sleeve castings are some variation of Grey Cast iron. For around a hundred years engine blocks and cylinders have always been Cast Iron. In the last few years Plated Cylinders have come into the picture. Fact is, it’s much less expensive to manufacture cylinders without the cast iron liner. We will probably see a lot more plated cylinders in the future. I like plated cylinders since it gives us more sleeving business as they wear out. The people who choose to have their cylinders replated are limiting their porting possibilities.

I must talk about the wonderful company, L.A. Sleeve. The Metchkoff family started the Cycle Sleeve business. I expect that they will always be the Big Fish in the pond. Gary Metchkoff unselfishly taught me the sleeve business back in the 70’s, I miss my friend. Along came the Weather Treated centrifugal cast cylinder liner. Gary told me that Weather Treated was coined from the fact that his liners laid on the ground in the back lot for a time. (Now you know The rest of the Story)


Portland Motorcycle Show, circa 1976 The first Sleeve Down 100cc Honda Elsinore

On a side bar, after the liner inventories bleed down, the price of commodities will rise and Liner prices will also go up, stand by. Liner castings are also becoming more difficult to purchase from the Big Guys, LA Sleeve & NW Sleeve. I found an Iron foundry & will again have some of my own castings from a local supplier as I did in my earlier years. Whether the castings are spun, investment or Green sand castings, all configurations work well if the castings are sound and free of flaws. Sure will be good to get what I need when I need it. I may show some of my pattern work when I remember to bring my camera along.



Sand castings work well and always will.



"Old Dog"
JT
:thumbsup:
 
#72 · (Edited)
More on the RM250

Back to the new liner installation of the RM250 cylinder. As they say, “You can take it off but you can’t put it back on.” I am rather conservative while cutting the new ports. Most of the Porting people are much better than I am doing this kind of work; after all, they have their Trade Secrets.


You will notice that the new ports are cut smaller than the acid marking indicates . The upper Boost porting still needs to be finished up. This gives the option of more performance increases if desired. I usually add some ribs in the areas which will give the piston more support. The new ports are also cut toward the Center Line instead of straight in.


The rear transfer port is usually the most difficult to install. One must be careful not to have the ports knife edge on the inside of the cylinder.


The exhaust port had a crack in the center rib which needed to be repaired. Another reason for the port grinder to be careful while cutting.


As with the other intake ports, the exhaust ports are cut to center to make them narrower.

I prefer not to concentrate on performance port work although I’ve done many. The performance Port Jockey needs a Flow bench and a Dyno to do things the proper way. For those Gentlemen who use a Flow Bench with your port work, this is your chance to speak up and talk about your skills. I’ll bet the readership would discover you and send work your way.
It would be great to write articles on the Flow Bench.


Finished Liner, I also need to wash up after the project is finished.


We will finish up this job with a Forged Wiesco piston.

We should have this project finished up next week.
"Old Dog"
JT
 
#73 ·
Some secrets of the trade

If your Mechanic uses a Lathe on his engine work he needs a good set of expanding mandrels. This set goes from 1-1/2” to 3-1/2”. Cost is around $1,000.00. Small price to pay for a shop who wishes to turn out quality work.




The Parallel Plate: I’m now chucking most of my 2-stroke cylinder work on the Parallel Plate.

With this beautiful part, the cylinder is clamped to the boring bar table with 3 stout C-Clamps.


I now can accurately measure the bore diameter from the bottom, since there is no longer any clamping equipment in the way. Good ¾” mill stock aluminum plate is very flat and accurate. I tested some plate and found it to be out less than .002” overall which

I guess I’m kinda poking fun at some of the other Cycle Shops. I’m more interested in education than hiding a special process.
“Old Dog”
JT
:D

More on Thread inserts tomorrow.
 
#74 · (Edited)
Thread Inserts "How it's Done"

Continuing along with the RM250: The cylinder is relined ready for finish honing. After taking a look at the head studs, I’ve decided to replace all of the threads with Stainless Steel inserts.

The stainless alloy inserts have a small tang at the bottom to allow a way to grab while inserting.



#2 & 8 are stripping & #6 is snapped off. Take a good look at the photo and learn what to look for. After seeing all of the cylinders with blown pistons on this site, I’ll guess that there are a lot more stripped stud threads then it would seem.

Back to the snapped off #6 stud. You shouldn’t just attempt to drill out a snapped stud with an electric drill. The bit can walk off of center line and cause more problems. Now we have replaced the drill press with a vertical milling machine. Instead of a drill bit, I’m using a 2 flute center cut end mill to remove the snapped stud.


The end mill does a straight down plunge and removes the stud without walking off the center.


Next, on all locations, I tap drill the hole and cut the threads.


You can see how handy the Parallel mounting plate is while working with the cylinder. No matter what the operation is, it’s always a problem getting a proper hold on the Dang thing. "Trade Secrets"




Last, install the inserts in all of the threaded holes.


The top of the new liner is decked with a .005” squeeze fit to seal the head gasket.

The small smudge above the reed valve pocket is from my 500 deg. Temp stick. I use the temp stick to keep track of the cylinder temperature when removing & replacing the new liner.

I’ve ordered a few lengths of 8x1mm threaded rod for machining new stainless head studs. When we receive a cylinder for thread replacement, I’ll supply new Stainless head studs to go along with the job.
18 & 8 Stainless steel, 18% Chrome, 8% Nickel. "Trade secret"
After the last few cylinder repair jobs, we are starting to work from the bottom so we won’t have to disturb any existing head studs. As seen earlier in this thread, pulling head studs is a pain.

As you have learned, assembling a tool box and shop with the proper equipment can be a life long project. If your young and have the ambition, you can do this too. Never give up on your education.

All for now “Old Dog”
JT
:D
 
#78 ·
Making the parallel plate

A customer brought in an old KX250 for a bore this week. As I am accumulating more parallel mounting plates I thought I’d show how we make them. As you scroll through my thread you will see some different and interesting equipment, some newer than others. Our shop is a good illustration of how a Small business can grow over time. It isn’t an easy trick as most of you know. Passing the family business along is a good thing.

Takasawa produces some beautiful machine tools. This one, a Mac V2E was our first and has served us well for around 20 years.


With some minor programming and set up the base mounting hole is machined in the aluminum plate. I pick up left over 6061 plate from a local metal supplied. This alloy of plate is extremely flat and works well for my parallels.


The pilot hole is drilled for starting the end mill cutter.



The finished mounting hole is machined and the plate is ready for drilling the fastening holes.



The fastening holes are marked with a transfer punch.






The KX is ready to bore. This system works so well that I wish I’d have thought about it years ago. We can now measure the cylinder from beneath without the clamping equipment getting in the way. 3 C-clamps holds the cylinder for centering. No need to remove the mounting studs.

This KX250 has a nice LAS liner installed. Some of you people have noticed the long boost port that is machined in the rear of this cylinder. The long boost port is a notorious hone stone snagger and is extremely difficult to accurately fit the piston. We use a set of spline stones to finish hone to size. I’ve suggested to Dave at LAS to put a horizontal rib in this port to make things easier to finish up.

Most smaller repair shops are not to interested in stepping up to a quality Sunnen hone when a portable hone with an electric drill will nicely do the job.

Whenever you have an idea for an improvement, speak up. Us little guys have just as much of a voice when somebody hears it. The canned replacement liners from the 2 big folks, L.A. & N.W. Sleeve Co's can always use some improvement. It's easy to imagine how frustrated a small shop must feel when attempting to do a quality liner installation and not being able to fit the piston properly.
Hand held hones with an electric drill can do a proper job if the sleeve is designed without the extra long stone snagger ports.
Later
"Old Dog"
JT
:thumbsup:
 
#79 ·
More on Port configurations

I took this picture to show this hone snagging boost port. One small horizontal rib in that port would help support the stones and produce a nice straight bore.


Another thing brings up questions in my mind, Exhaust Porting. This KX cylinder has a couple of auxiliary exhaust ports on each side of the main exhaust port.



Right side & Left side.

Our modern 2-Strokers are Loop Scavenged. i.e. the fuel charge takes a loop as it flows thru the cylinder. When the fuel charge exits the cylinder, it seems to me that those 2 small auxiliary ports won’t pass much exhaust. How about somebody else’s opinion?
I believe that the properly ported Butterfly type of exhaust porting would be much more efficient? How about some more input?

This cylinder has very conservative porting and can use some enlargement. I believe that the Butterfly exhaust porting is about the best way to go. Large area with no port snagging problems

Back in the Old Days I had friends who regularly raced the Komet engines on their Karts. The Komet cylinders had Butterfly exhaust ports which bridged the full width of the cylinder bore. It always seemed to me that this was about as good as it gets for removing the exhaust. The tuned exhaust pipe had plenty of area to work with.

How about some input from you Port Jockeys, Good or Bad is fine.

Later
"Old Dog"
JT
:thumbsup:
 
#390 ·
I took this picture to show this hone snagging boost port. One small horizontal rib in that port would help support the stones and produce a nice straight bore.


Another thing brings up questions in my mind, Exhaust Porting. This KX cylinder has a couple of auxiliary exhaust ports on each side of the main exhaust port.



Right side & Left side.

Our modern 2-Strokers are Loop Scavenged. i.e. the fuel charge takes a loop as it flows thru the cylinder. When the fuel charge exits the cylinder, it seems to me that those 2 small auxiliary ports won’t pass much exhaust. How about somebody else’s opinion?
I believe that the properly ported Butterfly type of exhaust porting would be much more efficient? How about some more input?

This cylinder has very conservative porting and can use some enlargement. I believe that the Butterfly exhaust porting is about the best way to go. Large area with no port snagging problems

Back in the Old Days I had friends who regularly raced the Komet engines on their Karts. The Komet cylinders had Butterfly exhaust ports which bridged the full width of the cylinder bore. It always seemed to me that this was about as good as it gets for removing the exhaust. The tuned exhaust pipe had plenty of area to work with.

How about some input from you Port Jockeys, Good or Bad is fine.

Later

"Old Dog"
JT
:thumbsup:
I would have to think the tripple ex would be most efficient as they can be closest to the sides of the cylinder. However the bridged (butterfly ?) port would be most useful for better time/area where tripples aren't possible due to either water jackets or lack of material or desire not to weld on outside of cyl., when they are retro-fitted. I know most if not all A.M. Banshee cyl. are tripple port. Easy to do when you start with a "clean" sheet of paper. Some have added tripples to Blaster cyl. even tho small in size they claim performance gain.

I had skimmed this thread before, but have started going through it. As you can see I've made it to page 8 :Clap: :Thumbsup2:
 
#81 · (Edited)
Triple exhaust design is far superior to a bridged exhaust
A winged bridged exhaust loses too much efficiency due to its size and shape especially at low rpm that falls under
The target rpm range of the pipe being used
Triples keep the charge strong and port area is better focused at the desired duration and opening
Also it allows for wide cordial widths to make great torque and retain ring support but the downfall is most all the
Pressure drops over the three ports in unison causing the power to be generally abrupt
And primarily designed for mid to top output because of its peaky nature



 
#82 · (Edited)
Dennis: Thanks for the dope. It would be nice if we could shoot a strobe light in the exhaust on the inside so we could see what really happens in there. You heard it from the man. It always seemed to me and the Kart people that the butterflied exhaust is more efficient.
If not then it isn’t. The E2S is a wonderful sounding board for different ideas.
JT
 
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