My ’14 Ultra is still at 103 cubes, but two winters ago when I had SE 585 cams installed I had the dealer send the heads out to be milled .050 inches. I had them use Cometic .030 head gaskets when they put it back together and made sure they turned on the compression releases. I guess I’m a bit north of 10:1 as far as compression ratio is concerned; how far north, I have no idea. So far, so good, no engine issues whatsoever.

I’m looking at SE 110 kit 92500039, which is a cylinders and pistons kit. The catalog doesn’t mention what the CR is with stock heads. I know that if I have the 110 kit installed on my bike it will increase the compression ratio, and of course with my milled heads the CR will be higher than it would be with stock heads.

I’m thinking of sending the heads out for some mild work, so I’m trying not to have to buy new heads. My question is, will installing the kit increase the CR to a potentially problematic high level, say 11:1 or more, if I again have them use Cometic .030s? If so, if instead I have them use stock head gaskets, which I’m given to understand are .045, will that result in an acceptable CR? Or do my milled heads prevent me from going to 110 period?

Thanks in advance.

 

I had the motor built over last winter. went from 96 to 103 stage 4 on a 2011 fatbob
When I was planning to have this build done, the plan was to go to a SE 110 stage 4 kit.
the builder talked me out of it, as the 110 is not as reliable as the 103 kit.
Now everyone has their opinions, but he's been building bikes for over 30 yrs for harley, and is one of their best builders in Alberta.
So i took his word for it.

And no regrets. Bike is a beast and has no problems keeping up with the 117 stage 1's.
bike came in at 103hp and 110trq on the dyno.

The only thing I would of done differently, is have everything bored out for the larger pistons. That would of bumped the horse power up to about 120hp+.
Friend of mine has same setup with the larger pistons, and that what he got after the dyno.

To each their own, but I would look at the 103 stage 4 kits. comes with everything, and the dealer can modify the kits if you want specific parts used. This kit was $5500 with labor. Not sure what the 110 kits are.
Or you can go another route, and go with the S&S kits. Little more money, but dealers can get the kits, and do the work.

 

I can't answer as to what your CR will end up at, but I went to 110" this past winter using an S&S kit with CR at approx 11:1. 126ft-lb, 122 hp. Couldn't be happier. No detonation issues even on the hottest of days.

 

You’re head porter should cc the chamber and see where you’re at now, getting valve job too? Basically find out what chamber volume you need with the 110 kit to target 10.8 comp or if touring mostly 10.5/6 for those 585 cams. Those SE kits typically come in .009/.010 in the hole and should be verified BUT. do not calculate compression based on zero deck height, you’d probably end up light. Use big boys or RBracing calculators to fill in all the blanks. If the .050 you’ve already cut puts you over 11:1 (doubt it) then plug in a Cometic 0.040 hg first to see where you’d be (better than stock).

 

I believe the 110 kit comes with 10:2 pistons.

 

So you actually had .050" taken off the heads and directed the dealer to use .030" gaskets and you had no idea what the chamber CC's where? Or how far up or down the hole you were? As noted above you have no effing' idea what your CR is now but your asking internet strangers what it will be after more changes?

May I suggest before you change anything in the future that you start with a plan. Then figure out all the variables and do the math ahead of time.

 

 

Pretty sure your compression targets are for the s&s 585's and it appears that the OP has SE585's. Those have an intake close of 36* so I'd think 10.2 would be about where he would want to be. That would be around 200psi

 

Based on the following:
Stock 2006^ heads are 86CC nominal.
~.0067" per CC cutting stock 2006 up, 96/103 heads.
Your cut puts you ~78.5CC
Stock 103 pistons are typically down .005-.007", and have ~1.5CC dish from valve reliefs.
This places you somewhere between 10.67 & 10.71:1 Very high for SE585 cams.
4" bore flat tops from a 110 drop on kit with .030" head gaskets will put you between 11.27 to 11.32:1

 

Correct was thinking SnS 585. In this case yup looks like the heads as they are would push psi too high. Cam swap would be an option.