yaegerb
04-26-2015, 12:49 AM
I had been working on my 85R, getting ready for the dunes this spring. In the last leg of this rebuild I put all new gaskets on the top end, tightened everything down and filled up the radiator with coolant. I let the bike sit overnight only to find a puddle of antifreeze under the bike the next morning. I double and triple checked all of my hose fittings and was perplexed as to where this fluid was coming from. Finally, I touched one of the "nodules" on my three piece TRX gasket and I notice a little tear drop of fluid weep down the side of the cylinder. Hmmm, this isn't good. When I was done inspecting I had found that fluid was weeping 360 degrees around the cylinder.....well crap.
What to do? Well, three options, mill the head/cylinder top deck, hand lap head/cylinder top deck or splooge the crap out of the cylinder head with RTV (btw, please don't do this one, unless you have no other option).
I thought I would try option 2. Hand lapping is something that I have always wanted to try. Do I have access to a mill?, yes. Call me nuts, but sometimes I like the satisfaction of doing something myself. Gives me a whole new appreciation for a hard job and afterward, I treat those parts with more respect after all the hard damn work I put into them...LOL
And here we go....I hope the following steps help out others when considering to hand lap a cylinder head.
First items I purchased were a custom cut 10x12" piece of glass, 150/320/600 sandpaper and some elmers spray glue. Note, when doing this make sure you are on as flat as surface as possble. I made my benches so I knew they were relatively flat and my level agreed with me. The glass makes for a VERY flat surface on an already trued work bench. If you are lucky enough to have access to granite, I highly suggest using that instead of glass. But don't fear! Glass works!
215154215155215156
Step 1: Create a stationary jig out of 4 scrap pieces of 2x4, screwed down to a bench and lay the glass in the center
Step 2: Spray the glass down with Elmers glue and let it dry for 2-5 minutes (this allows for the sandpaper to come up easier when changing out grits)
Step 3: Start with 150 grit paper and lay it down on your tacky glue laden glass
215157
Step 4: Get some blue dykem out...what the hell is that?? Don't have any? I didn't either, so I used a sharpie and coated the cylinder head. This helps in finding low spots.
215158
Step 5: Generously coat the sandpaper with WD-40
215159
Step 6: Now comes the fun part. Starting with a PROPER grit, (I used 150 because I had some serious warp and low spots) start sanding your part in a different patterns. I prefer the figure 8 pattern. The key is NEVER TO SAND IN THE SAME DIRECTION.....EVER. Circles are fine, straight sanding I don't recommend. Figure 8 is the most safe IMO. I set a timer to 10 minutes at a time. And i still went through 4 cycles with the 150 grit. This is what it looked like after 4 cycles of 150.
215160
Step 7: It was at this point I felt safe moving onto the 320 and ultimately the 600. I ended up doing 4 cycles of 320 at 10 minutes a cycle and then 4 more cycles of 600 at 10 minutes a cycle. This is what it looked like after I was finished. Was it 100%? No, but it was damn close and definitely six sigma worthy!
215161
So after that was finished I decided that I was going to do my cylinder top deck. Well, as one might imagine those pesky cylinder studs leave something to be desired. I began removing the studs and to my surprise they were all coming out! That is until the last one. You guessed it, snap. We will keep this PG-13 and pretend I said crap. In reality, my wife heard me yelling profanities through our garages into the house. I went ahead and removed the cylinder head and decided to worry about the stud replacement at a later time. I still had some hand lapping to do!
The steps for the cylinder are the same for the head. Get your jig, glass, glue, paper and marker all ready. I started with 150 grit on the cylinder top deck as it was also way out of whack.
215162
This is after 4 cycles with the 150. My fine tip sharpie is highlighting the low spots still left after an hour.
215163
This is after another 4 cycles with the 150. At this point I am thinking holy crap, this cylinder was warped beyond repair.
215164
Finally I could see the light and began working with the 320. this is after 5 cycles with the 320.
215165
After that I moved to the 600 and here was the finished product. Was it 100%? No, but damn close with a straight edge.
215166
At this point I was finished with the hand lapping and ready to move onto fixing the cylinder stud. You have two options here, helicoil and timesert. Everyone has their preference and after a bunch of research and experience with helicoil, I decided to go with a time-sert. I ordered the M8x1.25 kit from the thread doctor on Ebay. Note that this kit comes with 11.5 MM inserts and you also need to order longer inserts. I opted for the 18mm as the lower shank of the head stud measures 17mm. Here is a picture of the kit below. You get a bit, counter sink, tap and insert installer. You also need to get the oil for the insert installer and 266 loctite.
215167
A few words of warning when using a time sert or helicoil. If you don't have access to a drill press, please for the love of all things holy have an extra guy or two around to "assist" you if you must use a hand drill. They can watch if you get off center and give you a good smack in the back of the head. If you are using a drill press ensure that your press plate is absolutely dead nuts level. I took an extra 45 minutes to ensure level on mine.
Step 1: After leveling the press spend an extra amount of time to measure once, twice...hell ten times if necessary to make sure the bit will be drilling at the correct depth. The "well" of each stud pocket in the cooling jacket differs...great huh. So I took a conservative approach and drilled my to 21MM. Use plenty of oil.
215168
Step 2: Hopefully step 1 went well for you because its the hardest. Step 2 is nothing more than chucking up your counter sink bit and counter sinking the hole you just drilled because the insert has a lip that will ride on this "shelf" you create.
Step 3: Tap the hole. Again, have a buddy watch you do this so he can slap you when you are not tapping at 90 degrees to the cylinder top deck. Take your time and use plenty of oil.
Step 4: Oil up the insert driver and screw the insert onto the driver. Add locktite 266 to the insert, don't need to go overboard here. 266 is some strong stuff. Thread the insert into the hole and eventually you will feel it tighten up. Keep screwing and you will feel it get loose again and that's when you know the insert has seated properly. If all goes well, you should end up with something like this.
215169
And that's about it. I have put the engine back together and "knock on wood" it is holding all the antifreeze and the stud torqued down to proper specs. I hope this thread helps someone else out in the future.
What to do? Well, three options, mill the head/cylinder top deck, hand lap head/cylinder top deck or splooge the crap out of the cylinder head with RTV (btw, please don't do this one, unless you have no other option).
I thought I would try option 2. Hand lapping is something that I have always wanted to try. Do I have access to a mill?, yes. Call me nuts, but sometimes I like the satisfaction of doing something myself. Gives me a whole new appreciation for a hard job and afterward, I treat those parts with more respect after all the hard damn work I put into them...LOL
And here we go....I hope the following steps help out others when considering to hand lap a cylinder head.
First items I purchased were a custom cut 10x12" piece of glass, 150/320/600 sandpaper and some elmers spray glue. Note, when doing this make sure you are on as flat as surface as possble. I made my benches so I knew they were relatively flat and my level agreed with me. The glass makes for a VERY flat surface on an already trued work bench. If you are lucky enough to have access to granite, I highly suggest using that instead of glass. But don't fear! Glass works!
215154215155215156
Step 1: Create a stationary jig out of 4 scrap pieces of 2x4, screwed down to a bench and lay the glass in the center
Step 2: Spray the glass down with Elmers glue and let it dry for 2-5 minutes (this allows for the sandpaper to come up easier when changing out grits)
Step 3: Start with 150 grit paper and lay it down on your tacky glue laden glass
215157
Step 4: Get some blue dykem out...what the hell is that?? Don't have any? I didn't either, so I used a sharpie and coated the cylinder head. This helps in finding low spots.
215158
Step 5: Generously coat the sandpaper with WD-40
215159
Step 6: Now comes the fun part. Starting with a PROPER grit, (I used 150 because I had some serious warp and low spots) start sanding your part in a different patterns. I prefer the figure 8 pattern. The key is NEVER TO SAND IN THE SAME DIRECTION.....EVER. Circles are fine, straight sanding I don't recommend. Figure 8 is the most safe IMO. I set a timer to 10 minutes at a time. And i still went through 4 cycles with the 150 grit. This is what it looked like after 4 cycles of 150.
215160
Step 7: It was at this point I felt safe moving onto the 320 and ultimately the 600. I ended up doing 4 cycles of 320 at 10 minutes a cycle and then 4 more cycles of 600 at 10 minutes a cycle. This is what it looked like after I was finished. Was it 100%? No, but it was damn close and definitely six sigma worthy!
215161
So after that was finished I decided that I was going to do my cylinder top deck. Well, as one might imagine those pesky cylinder studs leave something to be desired. I began removing the studs and to my surprise they were all coming out! That is until the last one. You guessed it, snap. We will keep this PG-13 and pretend I said crap. In reality, my wife heard me yelling profanities through our garages into the house. I went ahead and removed the cylinder head and decided to worry about the stud replacement at a later time. I still had some hand lapping to do!
The steps for the cylinder are the same for the head. Get your jig, glass, glue, paper and marker all ready. I started with 150 grit on the cylinder top deck as it was also way out of whack.
215162
This is after 4 cycles with the 150. My fine tip sharpie is highlighting the low spots still left after an hour.
215163
This is after another 4 cycles with the 150. At this point I am thinking holy crap, this cylinder was warped beyond repair.
215164
Finally I could see the light and began working with the 320. this is after 5 cycles with the 320.
215165
After that I moved to the 600 and here was the finished product. Was it 100%? No, but damn close with a straight edge.
215166
At this point I was finished with the hand lapping and ready to move onto fixing the cylinder stud. You have two options here, helicoil and timesert. Everyone has their preference and after a bunch of research and experience with helicoil, I decided to go with a time-sert. I ordered the M8x1.25 kit from the thread doctor on Ebay. Note that this kit comes with 11.5 MM inserts and you also need to order longer inserts. I opted for the 18mm as the lower shank of the head stud measures 17mm. Here is a picture of the kit below. You get a bit, counter sink, tap and insert installer. You also need to get the oil for the insert installer and 266 loctite.
215167
A few words of warning when using a time sert or helicoil. If you don't have access to a drill press, please for the love of all things holy have an extra guy or two around to "assist" you if you must use a hand drill. They can watch if you get off center and give you a good smack in the back of the head. If you are using a drill press ensure that your press plate is absolutely dead nuts level. I took an extra 45 minutes to ensure level on mine.
Step 1: After leveling the press spend an extra amount of time to measure once, twice...hell ten times if necessary to make sure the bit will be drilling at the correct depth. The "well" of each stud pocket in the cooling jacket differs...great huh. So I took a conservative approach and drilled my to 21MM. Use plenty of oil.
215168
Step 2: Hopefully step 1 went well for you because its the hardest. Step 2 is nothing more than chucking up your counter sink bit and counter sinking the hole you just drilled because the insert has a lip that will ride on this "shelf" you create.
Step 3: Tap the hole. Again, have a buddy watch you do this so he can slap you when you are not tapping at 90 degrees to the cylinder top deck. Take your time and use plenty of oil.
Step 4: Oil up the insert driver and screw the insert onto the driver. Add locktite 266 to the insert, don't need to go overboard here. 266 is some strong stuff. Thread the insert into the hole and eventually you will feel it tighten up. Keep screwing and you will feel it get loose again and that's when you know the insert has seated properly. If all goes well, you should end up with something like this.
215169
And that's about it. I have put the engine back together and "knock on wood" it is holding all the antifreeze and the stud torqued down to proper specs. I hope this thread helps someone else out in the future.