Big Bore Project Part 2
#1
01-22-2011, 03:38 PM
Big Bore Project Part 2
Welcome to Part 2
Part 1 is Here
Part 3 is Here
Disclaimer: I am not a technician - just a regular guy who likes to wrench and learn along the way. I rely on the Harley-Davidson Service Manual and other assorted documentation. My articles are to illustrate my experiences and should not be treated as expert advice on how to do a project. Enjoy...
To port or not to port; that is the question.
Let’s get ready for part two. First, do you have both heads off? Good. Grab a beer and let’s talk about head porting. During the course of this project I learned a few things about engine building. Everyone has an opinion because head porting part science and part religion. Whether you thought about sending your heads in for a port and polish, or some serious Stage 3 or 4 head work, here is my two cents. Everybody who plays in this space will claim that their approach to head work is the best. Guess what? They are all right and none of them are wrong. Huh? How can that be? After all I’m talking the difference between a few hundred dollars going up to $1500!
I talked with a number of the usual head performance guys mentioned here on the forum. I think all of them have excellent products, all based on different approaches, philosophies, and applications. I encourage you contact any of these guys and see for yourself.
If you want my opinion, if you have an application that you need or want to squeeze every ounce of performance out of your engine, even if it means a few percent increase in performance at a large expense, then go all the way! On the other hand, if you want to get a nice performance boost but not spend big dollars attempting to get the last couple percentage points increase in performance, then consider the less expensive options.
Let me be honest. What I don’t know about heads can fill a book. What I do know is this forum has some great vendors that can help you figure out what fits your specific application.
Ok, put that empty beer can down. We have work to do!
Check this out. The heads are off so you can now see those dirty pistons.
Pull my what?
The next thing we are going to do is pull the cylinders off. Guess what? No bolts; just lift. Be gentle on those studs! The pistons will slide right out of the cylinder bore. As soon as I removed the cylinders, I set them aside and covered the studs with ½ inch pipe insulation like this.
Here is a picture of a removed cylinder. Take note of the O-ring on the dowel hole. Remove and discard. Keep in mind this O-ring stuck to the cyclinder. When you reinstall, the O-ring is placed on the dowel with a groove on it located on the crankcase deck. There are two dowels per cylinder and only one has a groove.
In case you are wondering what you can see beneath the pistons, here is a shot of the connecting rod down to the crank.
Ten years of College down the drain!
Warning: Failure to heed the next step in any way will lead to pain, misery, and suffering not seen since the Dark Ages.
Pack the bores underneath the pistons with clean shop towels. Make sure to a thorough job covering any possible way debris can get into the crank. Also ensure your lifter covers are covered with shop towels too. This is one part of the project you want to overachieve!
My friends, if you are in a hurry and you choose not to follow this step, then be prepared to open the crank case to retrieve whatever completely avoidable crap you dropped in there. Maybe like a piston Circlip? No, I didn’t do this, but wow, can you see it happening.
Pistondectomy
The next step is to remove the piston circlip and wrist pins. I think there is a lot of angst and misinformation concerning removing and installing the piston circlips and wrist pin, particularly the difficulty of installation. I will try and give you some assurance that it is not that difficult.
Circlips are seated in a groove on both sides of the piston. The circlips retain a wrist pin that connects the piston to the pushrod. You only have to remove one circlip on each piston. It does not matter which side the circlip is removed; whatever is easiest for you. There are two ways to remove a circlip: Look at the side of the piston where the circlip and wrist pin are inserted. At seven o’clock you will see a notch right beneath the wrist pin. The manual way to remove the circlip is using a mechanics pick or small flat head screw driver to lever the circlip out of the groove. The circlip is very snug, but once you get a tool on it you can lever it out.
Again, make absolutely sure you put plenty of towels over any opening on the engine case. If you don’t and you lose a circlip in the crank or cam chest, then you will be officially screwed.
The second way is to use a Kent Moore circlip remover/installer tool. This is the easy button for the task. The problem is I have seen the tool run as high as $140. It can be difficult, but not impossible to get the Kent Moore tool from Harley Davidson, but you will pay top dollar. Interestingly, this very same tool can be used in some General Motors applications. I purchased a used Kent Moore piston circlip tool on eBay for $69.50. If you are interested in this tool the part number is EN-46745. Remember, like many tools for these projects, you can sell them later. That is what I do.
Remove one circlip on each piston. The wrist pin can be pushed out of the piston and pushrod with your fingers. If the wrist pin will not move, then it can be gently tapped out. Take care not to damage the wrist pin’s surface. On one wrist pin, I needed to use a twelve inch socket extension. I wrapped one end with masking tape and tapped the other end with my rubber mallet. The pin easily moved forward and I was able to pull it out with my fingers.
Before removing the wrist pin entirely, hold the piston with your free hand. The piston will lift right off once the wrist pin has been removed.
If you choose to replace your lifters during this project, right now is a great time to do it. I am replacing my stock lifters with the Bob Wood Directional Roller Lifters.
Remove the four bolts on each lifter cover and set them aside. The lifter covers might be completely stuck to their gasket and be difficult to remove. My lifter covers stuck badly. I freed mine up by a combination of using a razor around the gasket and gently prying. My guidance is being really careful if you pry. This is when things can break. Here are the lifters with the cover off. Remove the lifters and anti-rotational pins with your fingers. Everything will remove with little to no effort.
So now the top end is completely torn down. For those who are going swap out cams you are very fortunate. Since the exhaust is removed you have easy access to the cam chest. For those of you who are swapping lifters, then you don’t have to worry about those either. Don’t forget, you can check out the thread I wrote last year on cam replacement.
https://www.hdforums.com/forum/touring-models/461066-cam-project-final-write-up.html
Assembly
The 107 kit from Jamie at Fuel Moto arrived. Since I already had the Wood TW6-6 cams I installed last year, along with adjustable pushrods, I only need to focus on the top end. Jamie’s kit came with the CP piston and ring kit, Cometic head gaskets, and every possible gasket and O-ring needed for the project. I also ordered the Wood Directional Lifters to quiet the valve train down.
The first thing I did was orient the pistons on my kitchen table in the way they will be installed. The larger indentations face inward.
Next up is to install the rings. If this is your first time installing rings on a piston, it is very easy with a piston ring expander. Before installation I washed the pistons and rings with soap and water to get any kind of debris off of them. After fully drying I lubricated the piston grooves with plenty of motor oil.
Before installing the rings, you will need to lubricate the new wrist pins and insert them into the piston. You need to install one circlip now, so you don’t have to fumble around with this when installing the piston on the connecting rod. I used the Kent Moore tool. It took a couple tries, but the circlip snapped right in with ease.
The very bottom groove on the piston holds a set of rings that are flexible enough not to use a ring expander. First I installed the expansion ring, which the spring looking ring. I spiraled this ring around the skirt of the piston so not to over expand the ring. It went right in. I then installed the upper and lower oil rings the same way. Remember, all three rings occupy the same groove
Second, I used the ring expander to install the black “second compression ring” in the second groove. I installed this from the crown of the piston. Next I installed the lighter silver/gray top compression ring.
Using my fingers I oriented each ring’s gap by spinning the ring with my fingers and a small screwdriver. The service manual is needed for these steps. The key here is to make sure that the ring gaps are not right above and below each other. The manual lays out the correct gap orientation.
The next step is to install the pistons on the connecting rods. First thing is to apply some assembly lube to the eyelet on the connecting rod as well as the piston wrist pin and piston skirt. Install the piston onto the connecting rod exactly the way it came off. Remember, the larger indentations on the piston face each other.
This piston installed in no time flat. With the Kent Moore wrist pin tool you will have grasp the handles firmly and apply plenty of pressure for the circlip to snap into its groove. Orient the tool so it aligns with the notch on the wrist pin bore on the bottom of the piston. I know the tool is expensive, but its worth buying and selling later.
If you choose not to buy one of these tools then here is a link from Big Boyz Head Porting to walk you through the manual way.
http://bigboyzheadporting.com/showthread.php?t=82
Let’s get on with it. We want our cylinders perfectly clean. I took mine to the sink and washed them out with some Palmolive soap. I don’t care how much cleaning these things get after machining, I’d rather take the extra step and make sure all metallic dust is out of there.
Next up is giving the cylinders a good drying. After that I installed the new O-rings onto the cylinder base.
Take the cylinders and put a generous amount of motor oil inside the bores. Don’t forget to coat the base O-rings with some oil too.
Important! Do not forget to put one O-ring on each dowel on the crank case deck. Remember the O-ring we peeled of the cylinder? Those need to be replaced. There are two dowels on each cylinder. The O-ring goes on the dowel with the groove around it. Rub some oil on the O-ring and install. If you forget these O-rings, bad things will happen. At least that’s what I was told. I’m just saying it would suck to take the engine all the way apart because we forgot a stupid O-ring.
Coat the piston rings with some extra assembly lube. Do the same on the cylinder bores. I started with the front cylinder. Using a ring compressor, the plier/band variety, and compress the rings. Align the cylinder with the studs and push down right over the rings. The ring compressor will slide down off the piston rings. Remove the ring compressor and then push the cylinder all the way down to the deck.
Before you repeat the process on the other cylinder you will have to rotate the rear wheel to raise the piston. Without some high tech tools you cannot rotate the wheel without the opposite cylinder riding out of the crankshaft deck durng wheel rotation. Here is a twenty cent solution. Use two of these ½ inch PVC unions from the plumbing section. Use two of the short head bolts just finger tight. The high tech solution looks like this:
I did not use a support plate because I didn’t want to spend the money on it. Instead I borrowed a couple blocks from “Bubba’s” toy box. That worked fine, in fact I don’t think I used the blocks one of the cylinders. No issues.
You can buy one of those cheap ring compressors that you ratchet from an auto parts store. The problem is there is no way to remove the ring compressor after you put the cylinder over it. Instead, you can install the pistons into the cylinders, lower the cylinder with the piston sticking out of the bottom onto the connecting rod. From there you will need an extra set of hands to insert the wrist pin and circlip.
Looking good! Now I have wait for the heads to get shipped in hopefully in a week or so. In the meantime lets install the new Wood directional lifters.
All you need to do is clean the lifters up in small dish of motor oil. I applied assembly lube to the lifter bores with my fingers and then some more lube to the lifters. Slide them right in. Install the anti-rotational pin and button everything up with a gasket and lifter cover. Torque lifter covers to 100 in/lbs. For this application I decided to use anti-seize on the threads. I don’t think these bolts need Loctite. Torque each bolt in an alternating manner. You will find a ball head hex wrench like this is an ideal way to tighten and remove lifter cover bolts when the cylinder is installed. I highly recommend a set of these in every toolbox.
Because Dawg Said So:
Before we get to cleaning all the rocker arm parts, there is an easy mod that we can do the rocker box. I have to give all the credit for this mod to Dawg. If you are getting some oil blow-by into your air filter, then this mod might help. Here is my breather assembly taken apart. See the two small holes on either side of the oil? Not a great picture, but the oil return holes are .060 stock.
Take a #43 bit and drill the return holes and you should get a very good result. A #43 bit equals .0890, so the return hole size is increased very reasonably. Some use larger bits, but why take a chance. If you go with a 3/32 drill bit, then you are way up to .0938; not a big difference, but still a difference.
I shop at Lowes and I could not find a #43 bit with the rest of the drill bits. I did find a 4-40NC tap and drill set for $4 in the tap and die shelf. That comes with a #43 bit. Long story short, pick up the bit and you will find the job is easy.
Everything comes out nice and clean:
It should be a week or two before my heads get back from Big Boyz. During your project it’s a good idea to pick a point to stop work to clean and inspect all your parts. Make sure all the bolt threads are clean and reusable. Every project I do I find a short list of hardware that needs replacing.
Part 1 is Here
Part 3 is Here
Disclaimer: I am not a technician - just a regular guy who likes to wrench and learn along the way. I rely on the Harley-Davidson Service Manual and other assorted documentation. My articles are to illustrate my experiences and should not be treated as expert advice on how to do a project. Enjoy...
To port or not to port; that is the question.
Let’s get ready for part two. First, do you have both heads off? Good. Grab a beer and let’s talk about head porting. During the course of this project I learned a few things about engine building. Everyone has an opinion because head porting part science and part religion. Whether you thought about sending your heads in for a port and polish, or some serious Stage 3 or 4 head work, here is my two cents. Everybody who plays in this space will claim that their approach to head work is the best. Guess what? They are all right and none of them are wrong. Huh? How can that be? After all I’m talking the difference between a few hundred dollars going up to $1500!
I talked with a number of the usual head performance guys mentioned here on the forum. I think all of them have excellent products, all based on different approaches, philosophies, and applications. I encourage you contact any of these guys and see for yourself.
If you want my opinion, if you have an application that you need or want to squeeze every ounce of performance out of your engine, even if it means a few percent increase in performance at a large expense, then go all the way! On the other hand, if you want to get a nice performance boost but not spend big dollars attempting to get the last couple percentage points increase in performance, then consider the less expensive options.
Let me be honest. What I don’t know about heads can fill a book. What I do know is this forum has some great vendors that can help you figure out what fits your specific application.
Ok, put that empty beer can down. We have work to do!
Check this out. The heads are off so you can now see those dirty pistons.
Pull my what?
The next thing we are going to do is pull the cylinders off. Guess what? No bolts; just lift. Be gentle on those studs! The pistons will slide right out of the cylinder bore. As soon as I removed the cylinders, I set them aside and covered the studs with ½ inch pipe insulation like this.
Here is a picture of a removed cylinder. Take note of the O-ring on the dowel hole. Remove and discard. Keep in mind this O-ring stuck to the cyclinder. When you reinstall, the O-ring is placed on the dowel with a groove on it located on the crankcase deck. There are two dowels per cylinder and only one has a groove.
In case you are wondering what you can see beneath the pistons, here is a shot of the connecting rod down to the crank.
Ten years of College down the drain!
Warning: Failure to heed the next step in any way will lead to pain, misery, and suffering not seen since the Dark Ages.
Pack the bores underneath the pistons with clean shop towels. Make sure to a thorough job covering any possible way debris can get into the crank. Also ensure your lifter covers are covered with shop towels too. This is one part of the project you want to overachieve!
My friends, if you are in a hurry and you choose not to follow this step, then be prepared to open the crank case to retrieve whatever completely avoidable crap you dropped in there. Maybe like a piston Circlip? No, I didn’t do this, but wow, can you see it happening.
Pistondectomy
The next step is to remove the piston circlip and wrist pins. I think there is a lot of angst and misinformation concerning removing and installing the piston circlips and wrist pin, particularly the difficulty of installation. I will try and give you some assurance that it is not that difficult.
Circlips are seated in a groove on both sides of the piston. The circlips retain a wrist pin that connects the piston to the pushrod. You only have to remove one circlip on each piston. It does not matter which side the circlip is removed; whatever is easiest for you. There are two ways to remove a circlip: Look at the side of the piston where the circlip and wrist pin are inserted. At seven o’clock you will see a notch right beneath the wrist pin. The manual way to remove the circlip is using a mechanics pick or small flat head screw driver to lever the circlip out of the groove. The circlip is very snug, but once you get a tool on it you can lever it out.
Again, make absolutely sure you put plenty of towels over any opening on the engine case. If you don’t and you lose a circlip in the crank or cam chest, then you will be officially screwed.
The second way is to use a Kent Moore circlip remover/installer tool. This is the easy button for the task. The problem is I have seen the tool run as high as $140. It can be difficult, but not impossible to get the Kent Moore tool from Harley Davidson, but you will pay top dollar. Interestingly, this very same tool can be used in some General Motors applications. I purchased a used Kent Moore piston circlip tool on eBay for $69.50. If you are interested in this tool the part number is EN-46745. Remember, like many tools for these projects, you can sell them later. That is what I do.
Remove one circlip on each piston. The wrist pin can be pushed out of the piston and pushrod with your fingers. If the wrist pin will not move, then it can be gently tapped out. Take care not to damage the wrist pin’s surface. On one wrist pin, I needed to use a twelve inch socket extension. I wrapped one end with masking tape and tapped the other end with my rubber mallet. The pin easily moved forward and I was able to pull it out with my fingers.
Before removing the wrist pin entirely, hold the piston with your free hand. The piston will lift right off once the wrist pin has been removed.
If you choose to replace your lifters during this project, right now is a great time to do it. I am replacing my stock lifters with the Bob Wood Directional Roller Lifters.
Remove the four bolts on each lifter cover and set them aside. The lifter covers might be completely stuck to their gasket and be difficult to remove. My lifter covers stuck badly. I freed mine up by a combination of using a razor around the gasket and gently prying. My guidance is being really careful if you pry. This is when things can break. Here are the lifters with the cover off. Remove the lifters and anti-rotational pins with your fingers. Everything will remove with little to no effort.
So now the top end is completely torn down. For those who are going swap out cams you are very fortunate. Since the exhaust is removed you have easy access to the cam chest. For those of you who are swapping lifters, then you don’t have to worry about those either. Don’t forget, you can check out the thread I wrote last year on cam replacement.
https://www.hdforums.com/forum/touring-models/461066-cam-project-final-write-up.html
Assembly
The 107 kit from Jamie at Fuel Moto arrived. Since I already had the Wood TW6-6 cams I installed last year, along with adjustable pushrods, I only need to focus on the top end. Jamie’s kit came with the CP piston and ring kit, Cometic head gaskets, and every possible gasket and O-ring needed for the project. I also ordered the Wood Directional Lifters to quiet the valve train down.
The first thing I did was orient the pistons on my kitchen table in the way they will be installed. The larger indentations face inward.
Next up is to install the rings. If this is your first time installing rings on a piston, it is very easy with a piston ring expander. Before installation I washed the pistons and rings with soap and water to get any kind of debris off of them. After fully drying I lubricated the piston grooves with plenty of motor oil.
Before installing the rings, you will need to lubricate the new wrist pins and insert them into the piston. You need to install one circlip now, so you don’t have to fumble around with this when installing the piston on the connecting rod. I used the Kent Moore tool. It took a couple tries, but the circlip snapped right in with ease.
The very bottom groove on the piston holds a set of rings that are flexible enough not to use a ring expander. First I installed the expansion ring, which the spring looking ring. I spiraled this ring around the skirt of the piston so not to over expand the ring. It went right in. I then installed the upper and lower oil rings the same way. Remember, all three rings occupy the same groove
Second, I used the ring expander to install the black “second compression ring” in the second groove. I installed this from the crown of the piston. Next I installed the lighter silver/gray top compression ring.
Using my fingers I oriented each ring’s gap by spinning the ring with my fingers and a small screwdriver. The service manual is needed for these steps. The key here is to make sure that the ring gaps are not right above and below each other. The manual lays out the correct gap orientation.
The next step is to install the pistons on the connecting rods. First thing is to apply some assembly lube to the eyelet on the connecting rod as well as the piston wrist pin and piston skirt. Install the piston onto the connecting rod exactly the way it came off. Remember, the larger indentations on the piston face each other.
This piston installed in no time flat. With the Kent Moore wrist pin tool you will have grasp the handles firmly and apply plenty of pressure for the circlip to snap into its groove. Orient the tool so it aligns with the notch on the wrist pin bore on the bottom of the piston. I know the tool is expensive, but its worth buying and selling later.
If you choose not to buy one of these tools then here is a link from Big Boyz Head Porting to walk you through the manual way.
http://bigboyzheadporting.com/showthread.php?t=82
Let’s get on with it. We want our cylinders perfectly clean. I took mine to the sink and washed them out with some Palmolive soap. I don’t care how much cleaning these things get after machining, I’d rather take the extra step and make sure all metallic dust is out of there.
Next up is giving the cylinders a good drying. After that I installed the new O-rings onto the cylinder base.
Take the cylinders and put a generous amount of motor oil inside the bores. Don’t forget to coat the base O-rings with some oil too.
Important! Do not forget to put one O-ring on each dowel on the crank case deck. Remember the O-ring we peeled of the cylinder? Those need to be replaced. There are two dowels on each cylinder. The O-ring goes on the dowel with the groove around it. Rub some oil on the O-ring and install. If you forget these O-rings, bad things will happen. At least that’s what I was told. I’m just saying it would suck to take the engine all the way apart because we forgot a stupid O-ring.
Coat the piston rings with some extra assembly lube. Do the same on the cylinder bores. I started with the front cylinder. Using a ring compressor, the plier/band variety, and compress the rings. Align the cylinder with the studs and push down right over the rings. The ring compressor will slide down off the piston rings. Remove the ring compressor and then push the cylinder all the way down to the deck.
Before you repeat the process on the other cylinder you will have to rotate the rear wheel to raise the piston. Without some high tech tools you cannot rotate the wheel without the opposite cylinder riding out of the crankshaft deck durng wheel rotation. Here is a twenty cent solution. Use two of these ½ inch PVC unions from the plumbing section. Use two of the short head bolts just finger tight. The high tech solution looks like this:
I did not use a support plate because I didn’t want to spend the money on it. Instead I borrowed a couple blocks from “Bubba’s” toy box. That worked fine, in fact I don’t think I used the blocks one of the cylinders. No issues.
You can buy one of those cheap ring compressors that you ratchet from an auto parts store. The problem is there is no way to remove the ring compressor after you put the cylinder over it. Instead, you can install the pistons into the cylinders, lower the cylinder with the piston sticking out of the bottom onto the connecting rod. From there you will need an extra set of hands to insert the wrist pin and circlip.
Looking good! Now I have wait for the heads to get shipped in hopefully in a week or so. In the meantime lets install the new Wood directional lifters.
All you need to do is clean the lifters up in small dish of motor oil. I applied assembly lube to the lifter bores with my fingers and then some more lube to the lifters. Slide them right in. Install the anti-rotational pin and button everything up with a gasket and lifter cover. Torque lifter covers to 100 in/lbs. For this application I decided to use anti-seize on the threads. I don’t think these bolts need Loctite. Torque each bolt in an alternating manner. You will find a ball head hex wrench like this is an ideal way to tighten and remove lifter cover bolts when the cylinder is installed. I highly recommend a set of these in every toolbox.
Because Dawg Said So:
Before we get to cleaning all the rocker arm parts, there is an easy mod that we can do the rocker box. I have to give all the credit for this mod to Dawg. If you are getting some oil blow-by into your air filter, then this mod might help. Here is my breather assembly taken apart. See the two small holes on either side of the oil? Not a great picture, but the oil return holes are .060 stock.
Take a #43 bit and drill the return holes and you should get a very good result. A #43 bit equals .0890, so the return hole size is increased very reasonably. Some use larger bits, but why take a chance. If you go with a 3/32 drill bit, then you are way up to .0938; not a big difference, but still a difference.
I shop at Lowes and I could not find a #43 bit with the rest of the drill bits. I did find a 4-40NC tap and drill set for $4 in the tap and die shelf. That comes with a #43 bit. Long story short, pick up the bit and you will find the job is easy.
Everything comes out nice and clean:
It should be a week or two before my heads get back from Big Boyz. During your project it’s a good idea to pick a point to stop work to clean and inspect all your parts. Make sure all the bolt threads are clean and reusable. Every project I do I find a short list of hardware that needs replacing.
Last edited by atrain68; 02-24-2011 at 10:35 AM.
#2
01-22-2011, 03:42 PM
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#4
01-22-2011, 04:52 PM
Road Warrior
Good write up as usual atrain.
#5
01-23-2011, 08:52 AM
#7
01-23-2011, 10:36 AM
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#8
01-23-2011, 03:13 PM
I went through a lot of deliberation on this and went with Bean at Big Boyz. I've only seen rave reviews on his work. I think Hillside and Tman are great choices too, but for a first build this should be perfect.
#9
01-23-2011, 03:41 PM
Road Captain
Big Boyz
Bruce is going to dyno tune my 120R when the snow melts. Right now i'm building an engine out of my takeout 96''. Did you do the Timkens and send the crank out? Haven't decided on Darkhorse or Revolution performance.
#10
01-23-2011, 03:44 PM
Road Captain