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Is 4 extra cubes worth it? If I was putting a 400 crank in a 350 block I'd say 30 extra cubes is worth the time and money but 4? Does it really make much of a difference? I currently have my motor apart and have to replace the Orings at the bottom of the cylinders so I'm thinking an overbore and pistons/rings may be in order. I almost have 50k on my bike and I am surprised to see the original ball hone marks in my cylinders. Is this normal? I also had what I felt was an excess of carbon build up on the tops of my pistons. I felt I had a good running motor but with all that carbon I can understand why I had some detonation issues on hot days. The carbon is gone. I cleaned them off. I plan on routing my breathers to a catch can rather dumping into the intake again so I hope that helps the carbon issue.
 

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Is 4 extra cubes worth it? If I was putting a 400 crank in a 350 block I'd say 30 extra cubes is worth the time and money but 4? Does it really make much of a difference? I currently have my motor apart and have to replace the Orings at the bottom of the cylinders so I'm thinking an overbore and pistons/rings may be in order. I almost have 50k on my bike and I am surprised to see the original ball hone marks in my cylinders. Is this normal? I also had what I felt was an excess of carbon build up on the tops of my pistons. I felt I had a good running motor but with all that carbon I can understand why I had some detonation issues on hot days. The carbon is gone. I cleaned them off. I plan on routing my breathers to a catch can rather dumping into the intake again so I hope that helps the carbon issue.
If everything remains the same then no, not really. But going to a 107" with all the right components that work right together the 107" will be well worth the investment. The key is that ALL of the ingredients in the soup compliment one another and it will be the best tasting soup you've ever had. Many choices out there so try and buy most of the ingredients from the same builder that has a proven recipe. I have run with a couple of 107" builds that Kevin Baxter did at Pro Twin Performance and all I can say is WOW! I know there are some other great choices out there but he sells the components and they are 2nd to none and built to last. Especially if you do his bottom end work. Just my 2 pennies.... Good luck!

P.S. I guess I must be hungry this morning. :wink:
 

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Routing to a catch can definitely will help. That + a good tune even better. Personally I would spend my dollars on the heads. Sheffer Performance got 110hp/118tq on a 103" with headwork by Dan Vance Racing, CR575 cams and a good pipe. Compression is not that high. CCC is about 190psi. Best Wishes on your build.
 

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Depends who you ask. If you have it apart then why not, I'm very pleased with my 107". Other things go into it, head work, cams, good exhaust etc. And a good tune is always recommended.
 

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Is 4 extra cubes worth it? If I was putting a 400 crank in a 350 block I'd say 30 extra cubes is worth the time and money but 4? Does it really make much of a difference? I currently have my motor apart and have to replace the Orings at the bottom of the cylinders so I'm thinking an overbore and pistons/rings may be in order. I almost have 50k on my bike and I am surprised to see the original ball hone marks in my cylinders. Is this normal? I also had what I felt was an excess of carbon build up on the tops of my pistons. I felt I had a good running motor but with all that carbon I can understand why I had some detonation issues on hot days. The carbon is gone. I cleaned them off. I plan on routing my breathers to a catch can rather dumping into the intake again so I hope that helps the carbon issue.
Norm, the reason you have the build up on the pistons is the way Harley runs their breather tubes into the breather box and then drawn into the intake. It's easy to reroute these without much effort and is so much better on your top end while giving you a little increase in power.

On the 107, it is one of those size engines that just work with the right combination. Something just gels when you go with 107. With the heads you are doing, flat top pistons, and the S&S 585 cam with stock throttle bodies and injectors, I've been seeing over 120 hp and 120 tq. easily. I was just talking with a couple of noted engine builders in our area about this motor and combination. It is also a build that is good for the long haul and doesn't beat itself up over time. Very reliable. They like to set the compression at about 10:2-1 and good to go. Call me some time and we will talk.
 

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Is 4 extra cubes worth it? If I was putting a 400 crank in a 350 block I'd say 30 extra cubes is worth the time and money but 4? Does it really make much of a difference? I currently have my motor apart and have to replace the Orings at the bottom of the cylinders so I'm thinking an overbore and pistons/rings may be in order. I almost have 50k on my bike and I am surprised to see the original ball hone marks in my cylinders. Is this normal? I also had what I felt was an excess of carbon build up on the tops of my pistons. I felt I had a good running motor but with all that carbon I can understand why I had some detonation issues on hot days. The carbon is gone. I cleaned them off. I plan on routing my breathers to a catch can rather dumping into the intake again so I hope that helps the carbon issue.
It depends on how much you are going to end up spending and how much power you want. Boring the jugs and a "street port" on the heads will be worth it since it is apart. If you are going to put some real money in the head work then no, I wouldn't do a 107". I would do a 124" LC kit on your cases and be done with it.
 

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Depends who you ask. If you have it apart then why not, I'm very pleased with my 107". Other things go into it, head work, cams, good exhaust etc. And a good tune is always recommended.
I am very happy with my 107 build. As others have said, talk to a builder and get a combination of parts that work together well.
 

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Discussion Starter #9
How much does a good set of pistons go for. I want them to clear the 190 valve if I decide to go with more lift in the future. Does anyone know of a good machine shop in California or NV? I'm glad Kirby is doing my heads but it cost me 50 to ship them across the country and I'm sure it will be around the same to ship them back. Maybe USPS would be cheaper. I'll see if it's an option.
 

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How much does a good set of pistons go for. I want them to clear the 190 valve if I decide to go with more lift in the future. Does anyone know of a good machine shop in California or NV? I'm glad Kirby is doing my heads but it cost me 50 to ship them across the country and I'm sure it will be around the same to ship them back. Maybe USPS would be cheaper. I'll see if it's an option.
Buy shore pistons online and have them ship them to Kirby to clearance the valve relief. Then Kirby will ship them back to you with the heads. Bingo.
 

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Discussion Starter #11
Buy shore pistons online and have them ship them to Kirby to clearance the valve relief. Then Kirby will ship them back to you with the heads. Bingo.
Dammit that makes sense. :grin:
 
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Depends on how much money you want to spend, I would say if your engine runs good when you tore it down to replace the cylinder base o-ring then why not save the coin and just put it back together. You can always put a 107 kit it the bike later on if the engine starts to burn oil or lose compression.
A good running 103 is a fine ride for touring and general riding and there isn't any real need for extra HP/torque unless you want to go fast and get up to speed quicker.
 

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I just put the fuel moto 107 in my bike with their 2 into 1 exhaust, level b heads. i love it, sound is awesome, feel is awesome and i am very happy. 4 little cubic inches can make a difference when its done with the right components.
 

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Let's face it Big Norm, depends on the $$$$ that you're willing to spend. There are some damn reputable #'s from the 107 that I have seen posted here over the last few years. I think it boils down to the builder that is doing the work and the tune or do you just want to go "BALLS OUT" and get the 124 and "ice the cake". Let's face it, it all comes down to what it is your budget. Personally I am still running a stock '13 RGU until I get the $ saved up to do the build that I want whether it's stage 2, cams, a/c, exhaust and tune or just say " to hell with it" and go with a 124 from a reputable builder. The choice is yours, Ride on brother!
 

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Discussion Starter #16
Thanks for all the replies. I will be reusing the stock cylinders this time around. Having done this work this time I feel extremely comfortable working on my own motor as I thought I would be. I get a lot of satisfaction doing my own work. So as said I will have no problem when I want to go bigger. My next step for the motor will probable be a few years down the road. I want to put an S&S crank in it and have the bottom end bore honed for a bigger cylinder. I will probably go 124 at this point. I just know the crank is the weak link and want to replace it.
 

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Since you said it will be a few years down the road you have plenty of time to research what it would take to build a 124 if that's the route you choose. Just consider the cost of an S&S crank, machine work on the cases, head work, and all the other needed parts plus labor and compare that to a crate 124 either from S&S or Dragos. I built a 117 once in an 08 Fatboy I used to have, by the time I was done I could have gotten a crate motor for about the same money. That's why this time around I got a 124 crate motor from Frank and couldn't be happier, also whenever I decide to sell or trade I can put my 103 back in and keep or sell the 124 and get some money back out of it. Just food for thought.
 

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I just put the fuel moto 107 in my bike with their 2 into 1 exhaust, level b heads. i love it, sound is awesome, feel is awesome and i am very happy. 4 little cubic inches can make a difference when its done with the right components.
What cams did you use?
 

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Discussion Starter #19
Buying a crate motor would be the smart route. I love the look of the Orca motor. I think it's a 136 or 139. But I think having a 124 with my matching motor numbers would be cool. :) I can't wait to get my 103 back together and see how my cams and headwork feel when I get on it. :grin:
 
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