A 124 build does not need a 4.250 case bore, if you use a 4.625 stroke crank.

 

In theory the 117 should last a little longer than a 124. 4.375 STROKE VS 4.625. Stay away from the 4.250 bore stuff, stick with 4.125 bore. 4.250 bore might work for some, but not worth the risk to most.
If you want longevity, stick with a decent cam with out too much lift..At/under/around .600 and compression at/under/around 10.5.

 

@gree:, esp wrt 4.250 bore.

In general, the bigger, hotter you go the more maintenance you will have. Questions to ask are: How much PMS do you want to deal with; and do you have a second bike to ride?

Not what you asked, but you might consider the 120R. Plenty of threads here to look at.

 

Could do moco 4.06 cylinders with a 4.08 bore for a 114 and change.

Cylinder walls should be plenty thick,cases plenty thick,bigger bore to take advantage of a set of worked stock or 110 head

Oh yeah and it is cheaper and I believe Randy at Hyperformance has the pistons in stock....you can spend more money on port work...both the TB if you have one or carb

Just a suggestion

 

Thanks guys.
I have a 103"er now with a set of SE 110" heads that were massaged on by WFO Larry...bronze guides, .030 milled, CNC ported, performance valve job, and AV&V .650 lift beehives. They flow 310 @ 28* @ .600 lift, and cc'd @93. I'm running Tman 625 cams with S&S roller rockers in SE forged rocker arm supports. SE 58mm T/B with 5.3 injectors. HQ Black Op's lifters, Baisley spring, SE 10.5:1 domed pistons, D&D Boarzilla exhaust, and TTS tuned.
It's a stout running little 103"er...it runs right next to my friends 120R until we hit 4th gear, then he finally stops spinning and hooks up...then he pulls me. :-(
I've been looking hard at the new S&S 117" cylinders coming out this month in the 4.125 bore. I had decided on sending my bottom end to either Tman or Darkhorse and having them work their magic with H-Beam rods and a Timkens upgrade, balance,true, plug & weld, etc. It's a coin toss on them...both do great work, I just have to decide on what size I what to go with this build.
Then Steve @ GMR threw some nice figures at me day before yesterday on doing a 120"er with him doing my bottom end and using a new SE 4 5/8 stroker crank and the 4.060 HD cylinders with his new 11.0:1 piston he designed for matching up to the SE head chambers ...which I did plan on re-using my heads. So...this threw a wrench into everything, and I don't know which way to go now.
The money is about the same (a little under 3K) for a 117 vs 120 vs 124.
120" = 4 5/8 crank in a 4.060 case bore
117" = 4 3/8 crank in a 4.125 case bore
124" = 4 3/8 crank in a 4.250 bore...scary thin bore to me
I plan on re-using most of the above mentioned parts in my up coming build...with maybe a different cam choice...but those 625's are as quiet as stock, and pull hard. I had the Wood 408-6's in it in the beginning and could not get rid of the little man with the sledge hammer to go away, no matter what I tried.
What do you's think? Suggestion or comments are all accepted!!!

 

Think?

Call Randy at Hyperformance.

Miles and miles of trouble free miles.

Thanks guys.
I have a 103"er now with a set of SE 110" heads that were massaged on by WFO Larry...bronze guides, .030 milled, CNC ported, performance valve job, and AV&V .650 lift beehives. They flow 310 @ 28* @ .600 lift. I'm running Tman 625 cams with S&S roller rockers in SE forged rocker arm supports. SE 58mm T/B with 5.3 injectors. HQ Black Op's lifters, Baisley spring, SE 10.5:1 domed pistons, Boarzilla exhaust, and TTS tuned. Stout running little 103"er...it runs right next to my friends 120R until we hit 4th gear, then he finally stops spinning and hooks up...then he pulls me. :-(
I've been looking hard at the new S&S 117" cylinders coming out this month in the 4.125 bore. I had decided on sending my bottom end to either Tman or Darkhorse and having them work their magic with H-Beam rods and a Timkens upgrade, etc. Coin toss on them...both do great work, I just have to decide on what size I what to go.
Steve @ GMR threw some nice figures at me day before yesterday on doing a 120"er with a new SE 4 5/8 stroker crank and a 4.060 HD cylinders with his new 11.0:1 piston he designed for matching the SE head chambers ...which I plan on re-using my heads.
The money is about the same (3K) for a 117 vs 120 vs 124.
120" = 4 5/8 crank in a 4.060 case bore
117" = 4 3/8 crank in a 4.125 case bore
124" = 4 3/8 crank in a 4.250 bore...scary thin bore to me
I plan on re-using most of the above mentioned parts in my up coming build...with maybe a different cam choice...but those 625's are as quiet as stock, and pull hard. I had the Wood 408-6's in it in the beginning and could not get rid of the little man with the sledge hammer to go away, no matter what I tried.
What do you's think?

 

Do you have a phone number for Randy @ Hyperformance? I'll give him a call and see what he has to say.

 

Randy is one of the VTF site sponsors.

http://kingofcubes.com/

515-266-6381

Good luck with your decision. Let us know of your progress.

 

I gave Randy @ Hyperformance a call yesterday.
He said that he can make me a set of custom CP pistons ($360.00) to set my compression for the 117" build. This is figured with a 58* intake closing set of cams. If he takes a 10cc dome piston and cuts it down to +7.5cc's for me...I'll end up with:
11.41:1 static compression
9.50:1 corrected
198.5 ccp's
If I do a 4cc cut I will have:
11.03:1 static
9.19:1 corrected
190.3 ccp's
Which piston cc would you's suggest?

 

Depends on how much low end torque you want to sacrifice. At 58 degree intake closing you'll lose some low end torque with lower compression, all else being equal. This can be made up some by increasing compression and will also be made up just by virtue of the fact that you'll be increasing displacement. Everything's a tradeoff. Personally, in a bagger, I'd do the higher compression just to have a more solid low end for cruising. On the other hand, the lower compression setup will be alot more foregiving as far as the gas available today, especially on cross country trips. JMO