Is it possible ?

[Bryantw82]

 So I have a 14 streetglide , 103 with d&d exhaust, s&s 585 easy start cams , power vision, s&s stealth air cleaner !! I wanna keep the 103 cylinders and pistons , is it possible to get close to 11.0:1 with milling heads and changing gaskets ?? If so how much exactly and what gasket ??

[Coff 06]

By the BigBoyz calculator you would have to cut your heads to 79cc to get to 10.80.With that much off the heads probably need to cut the intake too.No expert here,just guessing.       Coff 06

[kd]

I would consider a set of pistons and set to 0 deck.  I would think they are available. Check with a couple of the builder / vendors here. Maybe even 107 pistons.   

[Ohio HD]

Let's see, you get close to 11:1 with stock cast pistons and an S&S 585 cam set, so close to 9.9:1 corrected compression. Texas heat, cheap gas. Broken piston when you run the crap out of it?

I'd get a set of forged pistons to do the work and keep the meat on the head. Also what Coff said above about most likely fit up issues after chopping the heads down.

[Bryantw82]

Thanks for the input , that's why I asked cuz I am not 100 percent sure , can y'all tell me what's the size difference from 103 to 107 of piston ?

[Bryantw82]

The Texas heat is why I wanna keep it 103 and not bump up to 110 !! Heating issues !!!

[Ohio HD]

I would not bore it to 107" in that heat. The cylinders get really thin. Better to keep it at 103", chose a different set of cams, and less compression.

[kd]

I tend to agree with Ohio on the Texas heat.     My MVA heads went from 95 - 96 ish cc to 89 cc with a + or - .045 cut to even them up.  I did have to clean up the manifold about .030 each side to get a nice fit.

[doctorevil]

 the 103 cast pistons and raising the comp in a heavy bagger in the heat is a recipe for a disaster.

[doctorevil]

you know the 570 cam with a little headwork makes a great bagger motor on a budget.

[Ohio HD]

You're going to need the bike tuned in any event. And unless you're doing head work, larger valves, etc., the S&S 585 cams are not what you want. I'd stick with a bolt in set of cams and a good dyno tune. You'll be shocked how well it'll run.

I have no personal experience with this shop, but know a few that have spoken well about him.


http://topdeadcenterperformance.com/

http://topdeadcenterperformance.com/car-services/refi-dyno-tuning/

[Bryantw82]

I've had the 585 cams installed for a while with a tune ofcourse , I love the 585's , with what I have just barely get it rolling threw a 4 way then nail it , either it's spins it's ass off or pulls the front tire to the point I'm afraid the fender will drag !! All I wanna do is raise compression at this point !!!!

[Ohio HD]

 

[doctorevil]

we got suckered

[Coff 06]

                                      Coff 06

[Hillside Motorcycle]

If needing pistons, and naturally gaskets, then a 107" is a no-brainer.
Our J&E/Wiseco's have 6cc domes, coated skirts, 3mm oil rings, valve reliefs are set to facilitate large TDC's, large valves.

[Nastytls]

That's a mighty 103" to perform like that....

S&S makes a 79cc head, no cutting required.

[Kllongbrake]

With a 103" at under 11:1 that will lift and carry the front wheel of a bagger, why in the world would anyone want to raise compression? 

[1workinman]

I ride in the Texas heat to a point . Both of my bikes have a tad more compression than stock but as you know that depends on the cam shaft . I don't like to ride when its in the high 90 or more that's the reason I bought a 16 foot v nose trailer to go ride where its cool . But one thing that I found out on my bikes both have 640 SS cams is compression makes them shine . I use the wards cooling fans and don't ride in big city or stop and go traffic . Both bikes have oil temp gauges and I ride two up on both so I know what I can get by with . Of course a good tune is important . I don't use 87 octane fuel or have not so far . Do as you wish on your bike . For me I expect them to run and not  lay over

[Appowner]

The Texas heat is why I wanna keep it 103 and not bump up to 110 !! Heating issues !!!

On my 08 I initially did a lot of commuter riding in heavy traffic.  Temps became a concern for me until I went with an Oil Bud.  I saw a 30 degree decrease in my typical temps.

https://harleyoilcoolers.com/

[jmorton10]

Oil buddy coolers are awesome, I have one on my 124 inch road king & I love the thing.

~John