Next up, round 2-288xp rebuild

[roadster27]

When I started them I had a 2 yr old and a new born. Now I have 3 boys and not much time for my hobby’s. And I have quit a few hobby’s..... gonna have to start getting up earlier just to have some me time before the family gets up and Takes up my attention.

 

[roadster27]

To bring everyone up to date where I left off was putting the case back together. Heat the case to 230 deg. With a heat gun. Bearing will drop right in. Let the heat soak into the bearing for a few then the crank snaps right in. All by hand. Once cool it’s nice and thight again. Super easy.

 

[roadster27]

I also cleaned the crank with my wd40, scotchbrite, and string method. If I could remember how to post a video I will...

 

[roadster27]

 

[XP_Slinger]

Hi everyone. Sorry to dig up an old thread but I’m FINALLY back on rebuilding These pair of 288’s. Last post from me looks like a year and a half ago. View attachment 241327The saws hasn’t move from the bench the whole time. I just worked on my other projects around them. Its been to long and I would like my bench back lol.

That’s life man glad you’re back at it, looking forward to how they turn out.

 

[roadster27]

I have one of the 288’s back together all but the top end.

 

[roadster27]

I plan on getting the 2nd saw caught up to this one in the next few days. Then I plan on comparing some different cylinders against one another and see how they do. I bought 2 of the white box p/c kits when they where on sale For $19.99. I got to say for 20 bucks there’s not a lot of room for complaint. They look pretty good for the money we will have to see how the plating holds up during porting....

 

[roadster27]

They cylinders to be compared will be:
Stock Mahle w/ meteor piston this one cleaned up real well.

an early KS non decomp that someone else really “when to town on”! Also w/ Meteor piston. This is the one from earlier than cleanup but the plating is worn around the exhaust port... no to concerned about this one due to the port work by others. Not save able any due to it now almost open port transfers..last will be the two 20$ white box kits in above post, one stock one ported.

 

[roadster27]

The timing number are posted as is on top of each cylinder. They are taken with stock base gasket. I only have .040 solder so I could get a reading yet on squish from some.... I’ll have to get more sizes...
The 2 on the left are the white box, then Mahle, last KS on the right that’s One of the boys snack on the bench. As I said a lot of life happened while away from these projects lol.

 

[kanscruzer]

The timing number are posted as is on top of each cylinder. They are taken with stock base gasket. I only have .040 solder so I could get a reading yet on squish from some.... I’ll have to get more sizes...
The 2 on the left are the white box, then Mahle, last KS on the right View attachment 241410that’s One of the boys snack on the bench. As I said a lot of life happened while away from these projects lol.

Are those steel toed house slipper?

 

[roadster27]

Lol.....ummm, sure.... I’m on light duty for the next week and didn’t feel like getting out of my basketball shorts and house slipper... ... like I said I have 3 boys under 4.... I’m done.

 

[roadster27]

Question on the port timing of these jugs. I was expecting the ex to be more around 104 and BD around 20 degrees or so at stock but these seem to be more 99-100 stock... and a blow down around 15-16 degrees. I’m not looking at the KS jug as someone has messed with it pretty good. And the other 2 are cheap but seam to be in line with the Mahle...
Does that sound correct for a stock 288?

 

[roadster27]

Well I put one of the cheap jugs under the knife...the new number 102-117-76
.026” squish with gasket.

 

[roadster27]

I cut .015” off the base and extension just to get a good squish reading. My solder is only .040”. So now I have a good starting point. What is your guys recommendation for number on this cylinder? I would really like to do a squish band cut with my lathe as I haven’t done one yet... figure a $20.00 cylinder is a good place to start! Will most likely start with the intake and work my way up with the other ports. Would like to get what ever intake number I pick by dropping the jug to it. Probably set the squish at 20-25 when done. I LOVE COMPRESSION. Lol. Think I’ll clean up the intake a little but not much. I want good throttle response so I won’t be widening much. Might drop the center of port a little not sure yet. I can fine tune it with some grinding but would like to get close with the cylinder first. I’ve read somewhere around 78-80 work well for them. Can anyone confirm?
Also the exhaust looks to run good on these around 98,99,100 ish. And factory BD doesn’t look to be that hight, around 16 deg.

What numbers do you guys recommend?
I want a saw with good power but not a real narrow “peaky” power band... not looking for all out Hp on this jug. Want some torque too.... probably get some of that from the compression.

All recommendation are welcome.

 

[XP_Slinger]

The timing number are posted as is on top of each cylinder. They are taken with stock base gasket. I only have .040 solder so I could get a reading yet on squish from some.... I’ll have to get more sizes...
The 2 on the left are the white box, then Mahle, last KS on the right View attachment 241410that’s One of the boys snack on the bench. As I said a lot of life happened while away from these projects lol.

Very curious to see how that KS runs. I cut lowers on an HL cylinder the same way as an experiment but have yet to run it. Whomever worked on yours did clean work by the looks of it. Might be a great runner.

 

[XP_Slinger]

Question on the port timing of these jugs. I was expecting the ex to be more around 104 and BD around 20 degrees or so at stock but these seem to be more 99-100 stock... and a blow down around 15-16 degrees. I’m not looking at the KS jug as someone has messed with it pretty good. And the other 2 are cheap but seam to be in line with the Mahle...
Does that sound correct for a stock 288?

In my limited experience I agree that’s fairly short blowdown. My new production KS cylinder has 21 degrees of blowdown. But different isn’t necessarily wrong.

 

[XP_Slinger]

I cut .015” off the base and extension just to get a good squish reading. My solder is only .040”. So now I have a good starting point. What is your guys recommendation for number on this cylinder? I would really like to do a squish band cut with my lathe as I haven’t done one yet... figure a $20.00 cylinder is a good place to start! Will most likely start with the intake and work my way up with the other ports. Would like to get what ever intake number I pick by dropping the jug to it. Probably set the squish at 20-25 when done. I LOVE COMPRESSION. Lol. Think I’ll clean up the intake a little but not much. I want good throttle response so I won’t be widening much. Might drop the center of port a little not sure yet. I can fine tune it with some grinding but would like to get close with the cylinder first. I’ve read somewhere around 78-80 work well for them. Can anyone confirm?
Also the exhaust looks to run good on these around 98,99,100 ish. And factory BD doesn’t look to be that hight, around 16 deg.

What numbers do you guys recommend?
I want a saw with good power but not a real narrow “peaky” power band... not looking for all out Hp on this jug. Want some torque too.... probably get some of that from the compression.

All recommendation are welcome.

Given your compression mod I’d say 98/118/78-80 will give you the power you’re looking for.

 

[roadster27]

Very curious to see how that KS runs. I cut lowers on an HL cylinder the same way as an experiment but have yet to run it. Whomever worked on yours did clean work by the looks of it. Might be a great runner.

Well when I get these back together I’ll make a few videos of each cylinder cutting in some wood. You may be right. Might be a good runner.... When I first got that saw the jug had some bad transfer in it (I posted some before pics of it earlier in the thread). That saw also has a carb limiter on it so I suspect that may be why it burned up in the first place.... I will be plugging it before starting.

 

[roadster27]

Given your compression mod I’d say 98/118/78-80 will give you the power you’re looking for.

I think in there some where is a good place to start. If I do the math there might be a way to drop the jug and get the uppers close close to where I want without having to do much on them, as it looks to have short BD already, and when I take the ex up it should stretch that out a little. I don’t have a 90* grinder yet. I have a good friend that has one but I don’t want to tie his up for to long doing the port work.

 

[roadster27]

Sooooo, this jug started off pretty good. I PM’d a few guys and got some really great advise on a direction for the port work.
The plan was to cut .035” out of the squish and .050” off the base and extension. Putting the intake at 79* and the squish at .020”. These AM jugs have a lower intake than the oem ones so I couldn’t go much farther without getting the intake duration out of wack.
Base cuts I got down pretty good. today was my first attempt at a squish band cut. Went pretty well until I crashed the boring bar into the plating at the top of the cylinder... it’s pretty hard to see inside while cutting. I’m pretty sure I know how I did it and when. So that’s good. At least I learned something.... I need a better way to mount the jug for doing band cuts. I’ll try again on the other cylinder but that means we won’t be having a test run on it in stock form. Though my goals are to improve performance over the stock mahle. We'll see if that’s possible...