Boring factory 107" cylinders

[Adam76]

Thinking about doing a small increase in displacement on my 107" softail. I definitely don't want a "big bore kit" especially the 124 / 128" kits..... 114"/117" will be plenty power for me.

Is it safe to bore the 107" to 117" ? Or would it be a safer bet to just go to 114"?

I have found CP pistons and Wiseco both do the 117" pistons -- however, interestingly in the Wiseco catalogue, the 117" pistons require cylinder "Resleeve" ...

Any advice on which pitons to go with, and what size bore would be appreciated. Also need to make sure I can get a Cometic top end gasket kit to go with it.

Thanks.

[BigT]

I did a 117" build on my 2017 107" before they started making the 124" setups. I had good luck with the Wiesco pistons I got from Tman.
You cannot see attachments on this board.

[BigT]

I did a 117" build on my 2017 107" before they started making the 124" setups. I had good luck with the Wiesco pistons I got from Tman.
You cannot see attachments on this board.

I just remembered that I did start with the SE 114" cylinders which had a little thicker cylinder wall than the 107" cylinder. It was pretty common back then to take the 107" cylinders out to  4.125/117"

[Adam76]

Thanks BigT, do you reckon I should find some take off 114" cylinders just to be safe?

[BigT]

Thanks BigT, do you reckon I should find some take off 114" cylinders just to be safe?

I would personally, especially if you could find a set cheap.

[Ohio HD]

Depending on what you're looking for power wise. This is the cam that Rigidthumper spoke about that's only in OZ from Alpha Performance Engines right now.

These guys are in OZ.

Alpha Performance Engines

Their sheet is STD but still, lots of power from a 107"

[Adam76]

Wow, that's crazy power from a 107" 

[Ohio HD]

This is a CR483 that also is only available from Alpha Performance Engines. A broader power range. They don't say what size the motor was in the dyno run.

[JSD]

Adam also check Rams head services in Sydney. They do nice Heads for TC & M8 . Also the 124 kits are cheaper at moment as they have gone 128 or so and 131 on the 4 1/2"

[Adam76]

The 107" build by Alpha Performance you posted earlier  is an interesting build -- post #5.

If you simply add domed high comp pistons to a 107" motor that are the exact same bore as the stock pistons, what kind of machining is needed for the cylinders? Just a hone? How would they be an exact fit?

Thanks

[Ohio HD]

Probably buy some of the Cast Billet CP pistons in 0.005" Oversize. The cylinders need measured first to see where they are. Then just have a competent shop hone for the pistons.

Do not try to hone the cylinders +0.005" with home shop tools. They need to be honed by a precision honing system.

[JSD]

Ohio are you suggesting cast pistons? Interestingly i watched a tour of CP pistons factory. I see they dont use coating on the skirts as sold by S&S for example for a TC 3.937

[Adam76]

Probably buy some of the Cast Billet CP pistons in 0.005" Oversize. The cylinders need measured first to see where they are. Then just have a competent shop hone for the pistons.

Do not try to hone the cylinders +0.005" with home shop tools. They need to be honed by a precision honing system.

Thanks Ohio, if that's the case I might as well just buy the CP 4.08" pistons and bore my 107" cylinders to 114" with 11-1 compression. This will open up my cam selection a bit more and give me good streetable power.

[Adam76]

I did a 117" build on my 2017 107" before they started making the 124" setups. I had good luck with the Wiesco pistons I got from Tman.
You cannot see attachments on this board.

Hey bigT, did you have to resleeve your 107" cylinders like the wiseco catalogue suggests? Or did you just bore out the 107" to 117" with no issues?
Thanks

[Don D]

124" is cheap and reliable. Drag Specialties cylinders and KB595LCA005 pistons. If you are pulling apart, do not dabble. Make it run.

[NHBagger]

This is a CR483 that also is only available from Alpha Performance Engines. A broader power range. They don't say what size the motor was in the dyno run.

Top of the dyno sheet says it's a 114.
Also I believe Wes at CR does have a few of the CR483.
Rumor has it that cam will be in the new FM cam shootout.

[Ohio HD]

Top of the dyno sheet says it's a 114.
Also I believe Wes at CR does have a few of the CR483.
Rumor has it that cam will be in the new FM cam shootout.

Good eyes, I missed that.

I don't know the details on these two cams as far as who actually owns the specs / sales. If A.P.E. owns the specs and has an agreement with Cycle Rama, they may be the only dealer that has them. In any case I would think that A.P.E. would want to market them in the USA. As well it would benefit Cycle Rama.

[harpwrench]

Mastertechmiller on YouTube commented on one of his videos that the 485 has basically same timing as the 512, with lower lift.

[Adam76]

124" is cheap and reliable. Drag Specialties cylinders and KB595LCA005 pistons. If you are pulling apart, do not dabble. Make it run.

Yes, agreed. But the only thing stopping me from going straight to a 124" top end is the heavy duty clutch I'm going to need and with my busted left hand which gives me grief with anything heavier than the stock 107" clutch lever pull.
If there was a way to have a light clutch lever pull with a 124" motor, then I'm all in. 😁

[Adam76]

This is a CR483 that also is only available from Alpha Performance Engines. A broader power range. They don't say what size the motor was in the dyno run.

Top of the dyno sheet says it's a 114.
Also I believe Wes at CR does have a few of the CR483.
Rumor has it that cam will be in the new FM cam shootout.

I reckon a 114" big bore and a CR483 can would be ideal for what I want / need. 

[rigidthumper]

"I reckon a 114" big bore and a CR483 can would be ideal for what I want / need."
Add a Muller power clutch and Bob's your uncle!

[Adam76]

"I reckon a 114" big bore and a CR483 can would be ideal for what I want / need."
Add a Muller power clutch and Bob's your uncle!

Thanks, sounds like a plan.

Would a VP clutch be needed and what springs? STD or medium?

[Don D]

Don't forget there is a very good shop to do that work there
Hood Motor Service

[Adam76]

Don't forget there is a very good shop to do that work there
Hood Motor Service

Thanks Don, unfortunately he's in a different state, 3000 kms away so I'll have to find someone local.

What are your thoughts on a softail  slim exhaust for this build... Will S&S slip ons be good or do I need a good 2-1 pipe?

Cheers

[rigidthumper]

"I reckon a 114" big bore and a CR483 can would be ideal for what I want / need."
Add a Muller power clutch and Bob's your uncle!

Thanks, sounds like a plan.

Would a VP clutch be needed and what springs? STD or medium?

Use the heavy springs from HD (37000286)or EBC (CSK 236). That will hold all you need, and with the Muller setup, will make it pull like stock.