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[prodrag1320]

we`ve also done 100`s of 3.935 (98" & 107")bores and a couple on the 110`s,we`ve never had a problem,but have seen cylinders that were not centered when being bored,this will result in the cylinders being too thin on one side and will distort

[HILLSIDECYCLE.COM]

We've seen that here as well, Kirby.
On many occasions, when we suspect this, we've found that the cylinder base gasket surface, and the cylinder head gasket surface are not parallel, (from the point of manufacture) when set up, and checked on a granite surface plate/height guage, equipped with a .0005" test indicator, so the cylinder bore is actually being shot thru at an angle, not perpendicular, to the head gasket surface.
We can also verify/check that in our cylinder bore fixturing here, via holding the indicator in a magnetic base, touching off on the head gasket surface, and then rotating the cylinder.
Scott

[djkak]

Upon veiwing this info, at this point, all the OEM T/C cylinders bored to 98", and 107" out there, are going to pop! ...

It seems unlikely that an OE cylinder bored .050+ beyond its specified max will maintain the same degree of dimensional stability as the original.

My sense is that outside of a significant core shift, a set of .050+ cylinders like these wouldn’t necessarily experience a mechanical failure, or “pop”, but more likely the most obvious issue would be some increase in oil consumption; which may or may not be a concern to the rider.

as always, JMO

[HILLSIDECYCLE.COM]

It seems unlikely that an OE cylinder bored .050+ beyond its specified max will maintain the same degree of dimensional stability as the original.

My sense is that outside of a significant core shift, a set of .050+ cylinders like these wouldn’t necessarily experience a mechanical failure, or “pop”, but more likely the most obvious issue would be some increase in oil consumption; which may or may not be a concern to the rider.

as always, JMO

None reported back to us, and we DO, inquire.
Scott

[HD Street Performance]

The same base part is used for the 4.060 and the 4.00 bore. Different design drawing and machining instructions.

[Razorback]

 Keep in mind spigot length is much longer on the 4.060 "bigger bore" moco cylinders than the stock 110's keeping the piston stable at bdc.

[HD Street Performance]

Preaching to the choir.
The 113 and 120 are VERY strong motors by virtue of this fact. That stability keeps the rings in contact with the walls and helps shed heat too.

[Zinister]

Let me make sure I understand what you're saying for sure...I can buy 4.060 cyls and bore them out to 4.125? Making a 117" with my current 4.375 crank in my 110.

Is this what you would reccomend or buy axtell cyls to bore?

[HD Street Performance]

I do not recommend anything unless I have your parts in my hand but I will say that the 4.060 will go there and it will take a case bore to get the 110 up to 117"

[djkak]

As previously mentioned, the cylinder blank for the 4.000 cylinder is the same as the 4.060 cylinder. Outside of the bore diameter, the difference after machining is that the 4.060 cylinder is a little shorter; the spigot is larger in diameter and approximately .600” longer.

In an SE 113, the bottom of the piston skirt does not extend much, if any, into the lower .600” of the longer spigot. The 120R will of course, but it appears that much of the additional length was added to provide support for a typically unstable section of cylinder bore.

[djkak]

This photo shows the radius at the base of the spigot of both cylinders; 4.060 on the left.

[Lever]

things that make you go hmmmm

[clubbie]

Doesnt the other side of the 4.060 look exactly the same with the cut out for cyl to cyl fitment?

Anyway if the cross section is the same as 88/95 and 96/107 then I am happy they will hold up fine. If I have to case bore and new cylinders I wont bother with 113 straight to 117 for the added cost of pistons.

[djkak]

Doesnt the other side of the 4.060 look exactly the same with the cut out for cyl to cyl fitment?

The rear of the front (pictured) and front of the rear are cut out, as well as notches on the right for the piston oiliers.

Anyway if the cross section is the same as 88/95 and 96/107 then I am happy they will hold up fine. If I have to case bore and new cylinders I wont bother with 113 straight to 117 for the added cost of pistons.

The spigot cross-section for H-D’s 3.875, 4.000 and 4.060 cylinders are all approximately 0.090”. H-D’s 4.060 cylinder bored to 4.125 would result in a cross-section of roughly .060” at the spigot, which is the same as the 107” bore of 3.9375” on a 96” machine.

[clubbie]

djkak thanks for the info. Your knowledge on the cylinders is superb.
Whilst on the topic of cylinders does anybody know why the 2012 SE catalog on page 50 say 4.060 cylinders can not be used on a 110". I can only assume because when the case is bored the O ring groove does not provide a good gasket seal?