I've got a 2007 Deuce (SERT, SE AC, V&H BR dyno-tuned) that isn't quite keeping up with friends of mine who have recently traded up to 2008 SE Springers. I've resisted considering any engine mods so far as i want to retain reliability, but thats about to change. I don't want to consider a 110" kit (too expensive) and my dealer suggested an increase to 103".

I've spent most of today reading posts on 103-107 builds and i've probably got as many questions as i started with, although i hope those questions are a little smarter. I know i can't achieve the HP or TQ of a 110 upgrade, but done right i should be able to get very close for considerably less money. I'd like to aim for the neighbourhood about 90HP and 100TQ. I do a lot of my riding around town (up to 3500-4000rpm) and want to feel the power down low, but also want reasonable overtaking power around 3500-4500rpm on the highway, though I rarely push it past 4000rpm.

Would something like an Andrews 54H work well, or would the 26H suit better? What about the Wood 6-6 or 7H? What else should i consider? Would i also need to upgrade the throttle body or other ignition components?

I've figured out i'd need to port and polish the cylinder heads, and it seems worthwhile to be safe and have a manual compression release installed (especially if the compresison ratio increases from stock).

Is there much difference (in terms of extra parts and labor) in building a 103" as compared to a 107"?

(I'm resisting changing over the V&H BR at this time, though a 2-1 pipe might be a future option).

 

A Wood 7H,(or an 8, for that matter) with a 51mm HPI t/body, 107", and a D&D Fatcat, will FAR surpass the 90/100 number. More like 110/120, especially with a good* set of cylinder heads.
With a Wood 9B, expect to go 120/120, and more.
Scott

 

boring stock cylinders to 107" still scares me,go with the S&S 106" kit

 

a well built and TUNED 107/106/105 will out perform a stock 110 most days of the week.

You will be at 100 - 115hp and will above 115tq

I am on my second 107(1st got totalled) the price difference is about $100 in parts labor is the same. The difference between the 107 and 103 is very noticeable--I have used HQs stuff for three motor builds but there are others out there that are just as good--may want to check with S&S, T-Man, Hillside, GMR, AMS (105) and Zippers

 

And Axtell. 107. Very serious cylinders.
I have one from NHRS. They fitted the forged flattop piston and rings for me.

 

It seems like you know exactly what you want. To address reliability - a well prepped 103-107 will give you great reliability with meticulous assembly. And as others have stated, you will far surpass the 100/100 mark. There are many builders out there with reliable suggestions. Go with the suggestions, and not try to put a build together with a little of this and that as in most cases they can turn into "science projects" and may not turn out as expected.

a couple of good options to explore :http://protwin.com/103sporttouringpe...cepackage.aspx or http://protwin.com/107sporttouringpe...cepackage.aspx

 

If you are concerned about reliability, then dont go more than 103" if using your original cylinders. If your target is 106" or 107" go for a full kit from well known builders.

Im building my 07 Dyna now. Im going for 103" using original parts, Andrews 54H, CP Pistons & a new 2-1 exhaust.

My recommendation is to go for a 106" or 107" cylinders & pistons, choose cams according to your riding style & send your heads for porting.

great deals on ebay:

http://cgi.ebay.com/ebaymotors/S-S-1...item1c0f772376

 

There are those that still have concerns about boring stock cyls to a 107 (98 if orriginally an 88). There are many who don't and regularly do this. 98" and 107" builds are everywhere nowadays and I have yet to hear of a specific failure related to the boring of stock cylinders this dimension. Yes, Axtell, S&S, RevPerf and others make cylinders to these dimensions and they are nice products (and pricey) but IMO, they are overkill for a normal street build. Full on racing, yes, go for aftermarket cyls as insurance. And maybe if I was in Dubai like Rebel, day in and day out experiencing 120 plus temps ambient, I might recommend otherwise as insurance also, but for what we have here in the US and for the streetable builds, I see no issues.

I guess what I am saying is prove to me there are failures related to boring to 3.938". I am not digging my heels in and please dont take this as a challenge to your intelligence, I really want to know.

 

Dalton..... You're such a troublemaker!



so much so.... I agree with w/ ya!

 

Well, I guess you're right, 107" street builds using original cylinders could run ok if CR is kept at 10:1 or below.

I haven't heard of any 107" major issues too.