Everything2Stroke Forum banner

1 - 20 of 234 Posts

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #1
2015 WOW, happy New Year, where do we go from here? In the last 2 years I’ve covered about all of the kinds of top end work that we do. There are a few of you who have taken the time to show & tell some of their projects. I’d like to encourage any of you to do more write ups about some of your own special projects, anything which is shop related.
This is the first in the new post, “How it’s Done 2015”. We’ll keep the original “How it’s Done” on line for readers study & comments. As time permits, The first page index will be updated for particular projects.

It has always been my idea to pass along & encourage readers to learn the shop skills which are required to build & repair our equipment. Here in the US people working the trade skills are becoming more difficult to find. In my family company, it’s becoming more difficult to find a machinist for either manual or CNC machine tools. The trades are an honorable place for any person who is good with numbers & mechanical abilities to seek a career. For you younger folks, continue your education, the way to a higher living standard.

After being away for a number of years, it’s been exciting to return to the cylinder repair business. From where the work comes from, it’s obvious that there is room for more people to enter the cycle machining trade. I’ll be 67 this year & plan to keep going as long as I can. Full time retirement isn’t for me with all of the wonderful machine tools in the family business. Maybe someday there will be somebody who is interested in carrying on with my small endeavor.

At www.smallenginemachineworks.com we are starting to work with some investment castings for our sleeve production. My first shell mold pattern will be for some 250cc sized cylinders which consumes most of our production. The new blank sleeve castings will be available for mail order purchase. I’m busy digging thru my records & notes in order to produce castings which will cover most of the cylinders around the 66mm bores. As I move along with my pattern work, some of the procedures for shell mold patterns will be covered in this thread. One of the main problems with working with cast iron is the shipping costs of the heavy parts. We are always noting casting size requirements to get our best value in the weight of our raw castings

There has been much conversation about different kinds of sleeve material. Much has been said about centrifugal castings & ductile iron. Besides a sound & uniform casting, Material hardness has always been one of my main interests. I’ve found thru cutting experience that most 2 stroke iron cylinders are as soft as a dry dirt clod. (Japanese cylinders) Many multi cylinder & 4 stroke liners are extremely hard & require more than a few tool sharpening’s. Most of the older air cooled European 2 stroke cylinders are extremely hard. (Montessa, CZ & Husky to name a few) It seems to me that the slipperiness of the sleeve is as important as any other characteristic. One of the previous foundries which I’ve used would put an extra ladle full of nickel in each of our sleeve pours.

Mr. Dave Clinton, founder of Darton cylinder sleeves sent me this email about sleeves & cooling

Question to Dave; What is the best material for small engine cylinders? Best for heat transfer, Aluminum, not exactly what I was expecting.

John,
Great question, comes up a lot. The simple answer is that dissimilar metals react differently in all aspects of interaction with each other. This is true for coefficient of expansion and heat transfer. Any dissimilar material is impossible to permanently bond to each other in high temp environments. Iron typically absorbs more heat and depending on the alloy may or may not transmit all the surface heat to a host but it will always be a compromise when installed in aluminum. Therefore in an aluminum engine the best heat transfer would be with an aluminum sleeve, provided the metallurgy of each material is compatible.
Dave

Most information is all available on the net with a little Google searching.
I’m now on the subscription list for “The Engine Professional” www.aera.org magazine. The last 2 issues had an article called “The Sleeve Solution” by Mr. Dave Clinton. Mr. Clinton is owner & founder of www.dartonsleeves.com Reading Dave’s article’s on cylinder sleeves is a true learning refresher.

Please let us know if any of you have any other questions which we can help with.

“Old Dog” www.smallenginemachineworks.com John Tice 503-593-2908
“Nice Lady” www.northwestsleeve.com Linda Wagner 503-666-8430

Stay Tuned
:Cheers:
 

·
Registered
Joined
·
854 Posts
Hey John,

I will give you a call sometime this week, but in the interim for the thread here I thought I would share results on some engine case lapping based on advice you gave me in the other thread.

Previously I've tried to lap/sand cases with a couple squares of regular sand paper taped down to a thin piece of coffee table glass, and it didn't really give me good results. In the old thread John mentioned getting a belt sander belt and using it, genius because I had never thought of that! I went on McMaster Carr's website and ordered an 18x36in 220 grit belt for about $13. I cut it in two at the seam and clamped it down to a large marble dinner table. I still would like to buy a real granite surface plate sometime, but this works a lot better than the glass coffee table top I tried to use before.


_CPB0748.jpg
Engine case, for scale - all kinds of room which was a problem previously trying to tape 2 square pieces down and not catch and hang up on the edges, etc.

My methodology (feel free to correct or let me know of something better) is to run over the entire surface with a black magic marker before starting so you have an easy way to tell where your low places are at. I used a circular motion and changed ends as well as direction several times. After about 15 minutes or so, I would up with this:


_CPB0751.jpg

Pretty close! Still has a few lower areas, but not terribly bad. These cases had significant amount of welding and repair done to them on the gasket surfaces from previous catastrophic engine departures. You can see the one very visible repair in the crank case back into the air cavity. The other is in the counter balancer chamber in the front, and is not as obvious in this photo. After some more time, I completed each set of cases.



_CPB0754.jpg


I'm left with one small low area by a drain plug weld and repair I did, but oil is thicker and less likely to leak than air in the vacuum environment of the crank case once the machine is running. The big belt sander belt truly made this a MUCH simpler and easier task than any other time I've ever tried in the past. I'll no longer be scared to death of working around flat gasket surfaces when it comes to welding or machining like I was in the past!
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #3 (Edited)
When I grow up I wanna be just like you. A figure 8 motion is good when you've got the room.
A different way to do laps
Isn't it something that you can do with a flat kitchen counter.
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #4
On Cylinder Cross Hatch

When we talk about cylinder honing cross hatch, we are referring to a good platform to support a uniform piston ring break-in. As equally or more important is an even figure eight cross hatch pattern helps guarantee a uniform bore, round & straight from top to bottom.
I learned this years ago from my Tool & Die shop mentor.
:thumbsup:
 

·
Registered
Joined
·
52 Posts
Boring table

Winter project machining the boring table top, drilling and boring out the holes on the Bridgeport


Trying to find a local engineering firm with a large surface grinder was hard work, had to go to Sheffield about an hours drive but it was only £50 for both sides


The top is seated on to the stand using corking and m10 bolts just pinching on the underside so it can float and find its own level ( I hope )


Boring machines ready to go just need to finish off with the clamping system

I may even treat myself to a Kwikway one day

Big thanks to JT on his advise I think it will work a treat.

Lathemad Kev.
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #6
Kev; I'd recommend that the largest hole in your boring stand be large enough to mount a CR500 cylinder with the head studs still in place. Also the long slot needs to be at least 3" wide to do the Japanese 4 bangers. A few hunks of 1/4" aluminum plate are handy to make up some parallel torque plates for mounting the unusual cylinders, which are difficult to chuck up. I use 3/4" threaded rod, coarse thread for the hold down clamps. The clamps need to pivot at the base to evenly clamp most cylinders.


Torque plate example for a 250 Suzuki






An example of the pivot type of cylinder clamp on a flat head Harley.


Good customers & fun work if you don't mind dirty hands.
Your work will be in demand as soon as the word gets around. A nice website & working with E2S is all you need for advertising, all for FREE.

I'm just this weekend purchasing another Kwik-Way FWS 1-3/4 machine. I'll then have 2 machines per table. With my volume it's very convenient to have extra equipment when waiting for parts or boring twin cylinders. I think there is also another FW 2.2" machine with an OEM table. If any of you are interested, send me a note. Kwik-Way machines are no longer manufactured & the purchase at a good price is better than money in the Piggy bank.

:Cheers:
 

·
Registered
Joined
·
52 Posts
Hi John, any idea what price the FW 2.2" Kwikway is going for. I would like to know what would come in the tool kit and also ask if the table could be excluded in the sale to save on shipping costs.
Thanks for your time.

Lathemad Kev.
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #8
An FW Kwik-Way, I bought my last one for $3800.00. I offered $2000.00 for one that I’m looking at today, I won’t look at it till after lunch today.
Tool kit includes Micrometer, centering fingers & tool bits. Also the hold down kit for automotive engine bloaks.
Lastly, the lap jigs for tool sharpening.
 

·
2 stroke thinker
Joined
·
2,062 Posts
Unfortunately like you said John, they don't make them anymore !
It's a shame because, How many engines are there out in the marketplace Today?

The only boring bars that you could find is ... a Foreign knockoff which of course the accuracy is not quite the same as the good 'ole model which weighed...(just joking...like 4,000 lbs) because metal was a lot cheaper to manufacture machines back in the day.

The ones available today are the ones from a machine shop that are:

- Going out of business because, much large volume facilities (Jasper) are killing the competition.

- The shop owner has hit their retirement age and just want out to enjoy life.

Joe
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #10
I spent a few hours watching U tube for boring bars, The ones which use a cone for centering are rather Cheezy. The Kwik-Way machines don’t wear out so looking for them is the challenge.
 

·
Registered
Joined
·
52 Posts
Hi guys, just got the boring table clamps done and ready to do some rebores.



I was looking for some g-clamps on ebay and then found some at a mates house that he was willing to sell very cheap 6 for £10 job done.


Hope to collect some cast this week to finish the DT400
Lathemad Kev.
 

·
2 stroke thinker
Joined
·
2,062 Posts
Looking great Kev ! I am impressed with your and John Tice's set-ups of the boring tables !

Keep up the Great Work !!
Without you guys...Blown cylinders would be sitting in the backyard! or as a paper weight in the bathroom, holding down the newspapers for when you need reading material while poopin' ! LOL!
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #14
Everything looks really nice; you’re squeezed in a little tight, I’ll bet you build another stand. If you do, wait a while until you’ve got some opinions on what works well for you. I’ve got 5 machines now & one is sitting in the back room as a spare; 2-FWSII 2-FW & 1-Big FN.



Be so very careful as you gain confidence in your work. The minute that you think you have the tool setting figured, you will surely goof up a bore job. When you develop an inventory of liner castings you will feel better knowing that you’re able to fix a mistake. Never trust your boring bar micrometers; they will bite you in the BUTT when you’re not looking.
It’s sure nice to have all of the friends who we meet in E2S; Hat’s off to Billy :Cheers:
 

·
Registered
Joined
·
167 Posts
Iron sleeving aluminum blocks is one more of those operations that are deceptively simple as a concept, and amazingly tricky in practice.

Even though iron sleeves retain many advantages over the increasingly common Nikasil-plated bores, some top 2-stroke racing mechanics oppose sleeves on principle. They have seen evidence of the aluminum block expanding away from the iron sleeve, especially around the exhaust port, as evidenced by carbon soot accumulating between sleeve and block. Soot is an excellent insulator, the opposite of what's wanted for heat transfer. So if you want to (like me) or have to keep using iron sleeves, you might want to think about what you can do about this.

The Dalton site has some discussion of the very frequent inadequacy of water jacket design. This can result in hot-spots, semi-stationary areas of steam clinging to metal on the back side of the combustion chamber or exhaust port, and water vapor is another poor thermal conductor. Evans Coolant, for which I see Dalton is a distributor, has found that these hot-spots are very potent causes of detonation. Their coolant helps, but you first have to figure out how to flow the coolant so as to scrub away steam-bubbles. A factory water jacket design that works okay for intended use may be inadequate for racing. You might have to re-aim, move, or add to the coolant inlet and outlet fittings so as to scour off the steam bubbles. And you might have to aim the coolest coolant coming from the radiator to try to keep the aluminum block from expanding away from the iron sleeve. Certainly this is usually easier said than done.

I think it was someone on this site who made the wonderful suggestion that lovers of 2-stroke racing machinery should adopt as their universal emblem a photo or drawing of a piston with big skid-marks across the ring groove and down the skirt. I love it!! However, the fact that all 2-stroke racers have a coffee can (or bucket!) full of skidded pistons means that we might want to pay more attention to coolant flows, sleeve-to-block heat-dissipation, hot-spots, and so on, and not just always chalk this stuff up to jetting or timing.
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #17 (Edited)
New sleeves with leaky exhaust areas are fit too loose. I like to fit my installations with at least -.005” interruption, 4-strokes with at least -.010”. The only reason to fit the 2-strokers with less is because I need to remove them for machining the ports; the tighter the better.
As usual, Mr. Smitty has good ideas & advice. To sum things up; who is installing & how tight do they fit your new liner. A good tight shrink fit is surely better than the cast in liners which the Japanese folks install.
The Darton Sleeve site has many good comments about cylinder sleeve installations, it’s a good read although Darton specializes in automotive types of cylinder sleeves.

Quote from my web site;

When a new sleeve is fit in your cylinder to replace a worn Chrome or Nicasil, its customary to shrink fit the new liner with around a -.004” or so shrink or press fit. Since we are not removing the new sleeve as we would while port machining in a 2-stroke; we are now fitting our 4-stroke sleeve liners with up to a -.010” or more shrink fit. This extra tight fit with your new sleeve liner ensures the maximum heat conductivity from the iron sleeve to the aluminum cylinder casting. The minimum desirable skirt clearance which is possible with the extra tight fit ensures a longer cylinder life & cooler running combustion chambers.


This picture is a typical “Saddle on a Sow” type of installation which was sent to us for repairs. This kind or workmanship gives the rest of us a Black Eye. Know & trust your installer.


Another way to cool your top end sum more is to cut more holes on the intake side of your piston which improves the fuel flow below the piston crown. It’s customary doing this exercise to cause the reeds to function a full 360 deg. of crankshaft rotation.

JT
:Cheers:
 

·
Registered
Joined
·
167 Posts
John, you say you fit the 2-stroke sleeve half as tight only because you have to take them out again for porting. At what point (amount of interference) does a sleeve start galling the inside of the cylinder when you press it out? (Also, how much do you warm the assembled cylinder-plus-sleeve before pressing out the sleeve?). Couldn't you work with a tighter fit if the sleeve had a baked on moly-coating (which I've advocated here for other uses)? This is something I and a couple of other outboarders have done years ago(in a not quite comparable situation, but still to reduce galling). (I see Darton adds a phosphate treatment for corrosion; don't know how that would affect the pressing-out operation though).

Maybe better yet would be a layer of copper on the outside of the sleeve, chem-plated or electro-plated. That should both make the sleeve easier to press out (allowing a little more interference-fit) AND help thermal conduction across the iron/aluminum interface. And you could charge more, for those who want it!!

Regardless of the fit, aluminum wants to thermally-expand away from the iron. Therefore, keep it as cool as possible, at the areas where it gets the most heat input. A tall order for air-cooled engines, certainly, and even for water-cooled bikes and karts it's tough because your radiator and water supply are limited. Still, you can usually make some improvements. For air-cooled engines you can fabricate ducts to put the air-flow where you need it (do you really expect the air to come neatly around the front tire and brakes and forks and fork braces, and still blow directly at the front of your engine??!). And there are coatings that are supposed to increase heat dissipation over the manufacturer's black paint.

In water-cooled engines, admitting the coolant at whatever point is convenient, and letting it flow in haphazard fashion around to whatever point is convenient for you to put an outlet is not likely to give optimal results. Years ago I watched a friend, who had previously been in charge of the racing division of a major outboard motor manufacturer, installing stuffers and flow-diverters in the open water jacket of a racing outboard to get the coolant to do what he wanted. Keep the hottest aluminum (around the exhaust port and above the head) as near the temperature of the rest of the aluminum as possible helps preserve Tice's precise fits and make the sleeve-to-cylinder interface work.

(EDIT) John, what's the deal with that first photo? Did somebody bore out an iron sleeve and send you that? And what is the engine?

(EDIT) It's just Smitty, not Mr. And BTW, thanks for that Darton link.
 

·
2 stroke thinker
Joined
·
2,062 Posts
Lookin at that pic... It looks like a marine or snowmobile jug.

Unless, the angle that John took the photo, just looking at the corrosion or it maybe an optical illusion and the intake angle. ?
Looking at the intake "boost port" It looks like there's only one.

That one doesn't look familiar or common to a 2 stroke dirtbike or quad unless it's an extremely early model ?

Help me out John...what's that jug from?

Joe
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #20 (Edited)
We heat the cylinders to 500 deg & the sleeve falls out. I’ve not experimented with fits to see when things start to gall. I just go with many times of experience. Anything much past -.005 & things get very close.
Whether the sleeve had a special coating or not, the coefficient of expansion is the same. I’ve not taken the time to do this kind of experiment; I can’t risk a customer’s expensive cylinder to do any testing.

The first photo shows the poor fit that the other shop assembled the cylinder with.

This is a shot of the sleeve which came out of the cylinder. The people who installed these parts should go back to school & learn how to use precision measuring tools. I think that this is some kind of 250 KX Kawasaki cylinder.

Way back when Charlie Brown & I did some water cooled conversions; the water output of the cylinder was put at the top & the input went towards the bottom. The theory was the hot water would rise & exit the high side of the cylinder. This set up had no pump in the system, only the natural way that the hot water always raises.

125 Yamaha


320 Odyssey, reed valve & pumper carb
 
1 - 20 of 234 Posts
Top