s&s 4 in cylinders drop in

[1stop]

is anyone measuring these cylinders before install with plates? I see alot of dyno runs running these. just opened up a set & measured. trust surface side, top- 4.002, mid - 4.0027,  .5" from bottom- 4.005. 90 degrees from thrust, top 4.0025, mid-4.0015, bottom 3.999. is this the normal findings for these 4 in cylinders? torqued in plates to there specs. are harley 110-117 cylinders measurements more accurate? straight?

[kd]

Did you reposition the plates and remeasure and did you torque them in a slow sequence?  IMO those are all over the map and hard to believe they vary that much at 90 degrees to each other.  Possibly try again at each 45 degree interval in 1" incremental height positions.  That should give you more information and a real blueprint of the shape.  You can compare it to what you have for confirmation.

[Ohio HD]

I can't answer if the MOCO cylinders are better or worse. But those measurements do seem a bit extreme in variance.

As an example, below are the last set of S&S 4.125" cylinders I had bored +0.010". Keep in mind custom bored generally means setting the clearance above the actual piston measurement, and not a theoretical bore. Mass produced cylinders generally aim the bore at the numerical measure based on theoretical piston measures, not actual.



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[Don D]

I buy all cylinders from S&S unfinished so I can hone them properly. Way too many disappointments lately. Unfortunately their drop on cylinders I can't fix the hone without ending up with too much clearance. In some cases I have used Line2line or Swain coatings to build up a few thousandths. Some KB pistons STD bore are .001 OS to allow a cleanup on new cylinders.
My spec is +or- .0002 but try to hold .0001 top to bottom in both planes in plates.

[1stop]

care was takened to torque properly. it is just jacked up cylinder. measured other one without plate, similar measurements. what caused it, don't know. just did one job previously and measuring without plates held within .001 taper & out of round. and I have a 117 hd kit in box for a guy & hoping the are straight. just wondering what everyone else is seeing. the thin liners spook me.

[Don D]

Have not seen the 117 cylinders any better. Guys run them as they do with the 110 cylinders.  If they don't fail and blow oil that seems to be good enough..

[1stop]

the 117 cylinders I got , I checked with no plates were within a .001 straight with correct clearance. getting s&s stuff warrantied.  we'll see what next set looks like.

[jsachs1]

It's hard for me to trust anything that comes through the mail after all these years. I took the "bull by the horns" and made this set up for S&S  4 1/8" cylinders. A 2 for 1 shot on the CK10.
John

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[Don D]

Agreed, did the same. I have plates for most of them including Merch.

[mike jesse]

Are you guys using a head and base gasket when the final hone is performed?

[jsachs1]

Head only.