Everything2Stroke Forum banner

21 - 40 of 674 Posts

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #23 (Edited)
Do a google search on it & it will come up. Basically it's smoothing out the last little bits of the Cross Hatch.
Seems like some hype to me, but does have some validity. Who knows what will Pop up next.
JT
 

·
4stokesLazy2strokesCrazy!
Joined
·
7,770 Posts
I have used a 3 stone hone before on 2 stroke cylinders. Yeah it hung up and sucked real quick.
I'm 100% positive strokittwice has a different model lol
I'm no genius but I kinda think Scott is using one with longer stones then mine.
Keep up the great work JT. This thread reminds me of an episode of 'how it's made' but better cause we can ask questions.
 

·
PLAYTIME'S OVER BITCHES!!
Joined
·
13,056 Posts
I have used a 3 stone hone before on 2 stroke cylinders. Yeah it hung up and sucked real quick.
I'm 100% positive strokittwice has a different model lol
I'm no genius but I kinda think Scott is using one with longer stones then mine.
Keep up the great work JT. This thread reminds me of an episode of 'how it's made' but better cause we can ask questions.
Paulie, the fact that i have bigger stones than you shouldnt be talked about here, lol. the stones on mine are around 3 1/2 inches long. i'd have to measure them agian. i have used others like mine before i went and bought it. i was looking for a ball hone, but couldnt find one locally small enough for the shee cylinders. i also use my hone on a drill press and not free hand with a hand held drill. that might help with it going in and out and the blades not getting hung up. i also dont have them set up for max pressure either. i dont want them to actually start to remove metal, only the glaze.
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #26
Friends: all of the tools that we talk about are available on EBay if you look. Think about investing in your quality tool box. Micrometers, Dial bore gauge, & a quality hand hone. It may take a while because of the cost but it won’t break you. Check for Ammco or Lyle hones. You can pick up a used Sunnen hand hone for a few hundred bux. I purchased my set of Brush hones from Wiseco. If your only doing a cross hatch job, the brush hone is the best choice. Brush hones never wear out they just wear down for a smaller bore.
The Dial bore gauge is available from www.cavcosales.com . Cavco is my major equipment supplier.
“Old Dog”
JT
 

·
4stokesLazy2strokesCrazy!
Joined
·
7,770 Posts
Paulie, the fact that i have bigger stones than you shouldnt be talked about here, lol. the stones on mine are around 3 1/2 inches long. i'd have to measure them agian. i have used others like mine before i went and bought it. i was looking for a ball hone, but couldnt find one locally small enough for the shee cylinders. i also use my hone on a drill press and not free hand with a hand held drill. that might help with it going in and out and the blades not getting hung up. i also dont have them set up for max pressure either. i dont want them to actually start to remove metal, only the glaze.
hee hee haha buddy!
I'm sure using the cheap one I had on a jug with the gaping hole of an exhaust port my 400 has didn't help.
 

·
Registered
Joined
·
854 Posts
Hey Guys, I'm gonna go through and moderate a few posts in this thread. I'd like to keep it on track with questions and answers specifically to what John is writing here. I do definitely encourage further questions/discussion on related topics though :)
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #29 (Edited)
Hi Guys:This is a little off subject but one of my projects for today is an .080”, 2mm bore job on an old 160 Honda twin


Take a look at the stones on my Sunnen machine


The stones are twice as long as the cylinder liners. This set up is smooth & won't
hang up.

I picked up a new toy last weekend. It’s an RTV500 Kubota side by side.

I have MS and don’t get around as well as the rest of you. Sure is great to get out in the woods and explore.
“Old Dog”
JT
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #30 (Edited)
Liner installation

Our next Project: This installment will be ongoing for a while. We are installing a new sleeve in Billy’s 86 CR250R Cylinder. Billy gets the first project since Billy Owns this web Site, LOL :)
It’s nice nowadays to be able to work on vintage equipment that wasn’t around when I started. When I started a vintage 2-stroke was a Harley Hummer. A little old cast iron 2-stroker from Harley Davidson.

Whether Plated or not I feel a new Sleeve is a better choice than a replate job, if there is a selection of oversized pistons, “Run the Numbers”. Way back then, I found a Hard Chrome Plater who said he could plate cylinders. I did one for Terry of “Hegar 4 Products” and someone else. We weren’t thinking about the fact that the new pistons had Chrome plated Rings. CRASH, Remember that.

There are a couple of different kinds of 2-strokers to talk about.
Plated cylinders:
The newer & Late model engines mostly all have Plated cylinder liners, 2 & 4 Stroke alike. I believe that this technique is used because it makes the engine blocks cheaper to manufacture. If any of you have a different idea, please chime in. Maybe better heat dissipation, although the cast in cylinders have always worked just fine, Air & Water cooled alike.
Plated Cylinders are a simple slick sleeve installation job with liners from our friends from N.W. & L.A. Sleeve Co’s. Bore em out and drop the new liner in. You’d be surprised how many people still screw them up, despite the ease of instillation. Aluminum is tricky to hone without the correct types of stones. Another case for Sunnen products. The shrink fit needs to be just rite for enough time to align the ports yet still having a tight fit at operating temp.

Cast in cylinders: Just about all Japanese and a few European engines have Cast in liners. They are more difficult to reline because of the flanges on the sleeves to keep them from slipping.

Both examples of cylinders with Cast in liners


KT100 Yamaha Kart


Husky Cylinder


Big Bore Yamaha preparing for base gasket area machining.

CZ, Bultaco & Montessa to name a few, have a shrink fit Flanged removable liner. The old 125 SACHS “Penton” had a shrink fit liner without an upper flange. They used to drop when the engine overheated. That old SACHS engine worked Great with a D.H. Reed valve installed.


Back to Billy’s Project: The CR250 has a cast in sleeve.


I start from Scratch to get the ports the way we want them to go. My castings come raw from a local foundry in the valley.


Just before welding, a fresh Bead Blast job. The CR250 cylinder with the lower flange removed.


Machining the cylinder base after Welding


Roughing the Sleeve I.D. All of this work is done on a manual Lathe. CNC Equipment is reserved for production machine work.


Next time we’ll be fitting the blank liner and cutting the ports. I used to keep this process a secret for those who would purchase my handbook. You can still order it for a mere 20 BUX. I’m getting too old so I’ve decided to show all of you folks how it’s done. When you learn how to do it, don’t think that it’s an easy job. Cylinder machine work is difficult and takes many years to learn to do it correctly.

My 10 Picture limit is here, so time to end for now.
Keep your Finger Nails CLEAN
Later
“Old Dog”
JT
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #31
How strong is that Forged Piston?
There seems to be interest in the strength of Forged vs. Cast Pistons. I didn’t have a cast piston to crush in the press for a demonstration, but we’ve all seen enough carnage and know how cast pistons fly apart.



I did find an old forged Wiseco to give a substantial push demonstration. I put this old Trooper Wiseco in my 60 ton press and gave it a shove. The piston didn’t start to fail till around 40 tons. I took these photos at 50 tons of pressure.

2 Views of the same Piston after a 50 ton push




Not much needs to be said after a look at the pics.
I give Wiseco Piston a Thumbs UP.
“Old Dog”
JT
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #34 (Edited)
Billy's CR250R Liner installation

Back to Billy’s CR250R
I’ve been tinkering with this project for the last month or so. Last week I fit the new sleeve into the cylinder and etched the ports. You’ll
See that with a proper etching job that there is ZERO guesswork as to where to accurately cut the new ports.

Nitric Acid is EXTREEMLY Dangerous. USE GLOVES AND PROPER EYE PROTECTION BEFORE attempting this step.


View of the cylinder after soaking it in Nitric Acid for the etch. Notice the aluminum press block is stacked ready for a push if
Necessary. This cylinder was heated for an expansion at temperature test. At 500 deg. The cylinder expanded approx. .010”


The torch is visible for heating. I use a 500 deg. Temp stick to monitor the heating progress.
The new sleeve has a .0035” shrink fit. If you purchase my Hand Book, further details are included to remove all of the
Guess work. If everything is calculated properly, the new sleeve drops out when the proper temperature is reached.


The etched sleeve before the Acid rust is cleaned off.


I use a Scotch Bright wheel on the buffer to clean off all of the Oxide.


The finish & Cleaned up Sleeve is ready to cut.



At this point, much thought needs to be injected into the project. We’ll put a rib into the intake area after the reed valve in order to give the new piston better support. Billy is one of those “Hot Shoe Port Guys” so he can add the knife edges or whatever else.
Many of you fellas have your own theories as to multiple port locations and heights. It would be nice to get some Proof from DYNO printouts. The same goes for Intake sides of pistons. The piston strength needs to be the main consideration at this point.



We used a Wossner piston for this project, because of their inventory and size selection.
I was originally thinking about inserting a DH style of boost port at the rear of this cylinder. It’s kinda a squeeze so that will happen with another project.

Hopefully next week, we'll start making chips on the Mill.



Later “Old Dog”
Keep your Finger Nails Clean
Feel free to through in some questions at any time
JT
 

·
4stokesLazy2strokesCrazy!
Joined
·
7,770 Posts
This is awesome stuff Mr. Tice.
The etching to see where the ports belong is genious.
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #38
Cast vs. Forged Pistons pt. 2

Cast vs. Forged Pistons pt.2

Hi Friends: This one turned out to be a Big surprise to me. I just finished a bore job on an old Yamaha RD250 twin. The customer was kind enough to donate the pistons to our project

I wish I’d shot a Video of the Push









My large press was a little over kill for the Yamaha piston. The piston started to crack almost instantly. I wasn’t able to get any kind of pressure reading


The pair: Small, Yamaha Cast
Large, Forged Wiseco.

This is a total guess but it seems as though the forged piston is 5-10 times stronger than the cast piston. This shows you folks the true story between Cast & Forged pistons.
www.smallenginemachineworks.com
“Old Dog”
JT
:thumbsup:
 

·
Vendor
Joined
·
1,500 Posts
Discussion Starter #40 (Edited)
CR-250 Project

I’ve removed the blank liner this week and cut the ports.

Etched New liner with the ports marked


Machining





Finished Sleeve after milling & Bead blasting. The new sleeve has a bridge/rib installed in the intake area
to better support the new piston. The concern here isn't as much high performance as it
is life of the cylinder. You guy's spend hundreds of $s on your top end jobs. There may be other
ways to pick up that last .00s of a second that you will loose from the extra port rib.
The new replacement sleeve's that my friends produce mostly all have the supporting ribs removed.
Carefully think about all of this before you fork out the Bux $$$ from your back pocket.

The 2 Liner manufacturer’s who I know are very kind and open to suggestions. If you give them a call, don’t
Hesitate to ask about changing the ports around.


After the new sleeve is installed the ports are matched up closer with the die grinder.



The Cylinder is re-heated before sleeve installation. Others recommend that your cylinder
is heated for 45 minutes in the oven before liner installation.
I use a 500 deg. Heat stick with a Propane Weed Burner. When the cylinder is up to temperature,
the new sleeve is lowered into place.
This process saves a lot of time and keeps the STINK out of your Kitchen.



After the new sleeve is droped into place a Brass poker us used to tap the ports
into alignment. In around 5-10 secands the new liner locks into place. One must work quickly.
Finally, a weight is placed on top to hold things in position while cooling.


You can see the extra piston support by adding extra ribs in the intake area.

The top of the cylinder will be decked & a few thousanth's of the new sleeve is left higher in order
for the head gasket to seal tightly. An extra base gasket is used to take up the differance.



We'll use standard Yamaha 8mm head studs instead of the flanged Honda type. We won't need to
notch the new liner for the flanged Honda stud. This will give some extra head gasket sealing surface.


Chasing 8x1.25mm Head stud holes

Lastly, the cylinder is bored and honed to size. Please ask any questions that you all may have.
We are here to help educate you on all of this stuff.


One of the next project’s is a V-6 Mercury with a blown center cylinder. This will be one of the
Largest challenges.


We are always looking for a challenging project to write about in E2S. If you have some time,
We’ll do your cylinder at a reduced cost & feature it in the site. Send me an email to talk about your
Special project. I’m always up to the challenge. [email protected]
Stay tuned
"Old Dog"
JT
 
21 - 40 of 674 Posts
Top