103 vs 107 build advice needed

[Adam76]

Hello,
I have a riding buddy (not on the forums) that has a 2016 Softail Deluxe. His current set up is a/c, maximus tuner and freedom 30" true dual shark tail exhaust, stage 1 download (yes I know it's a poor exhaust choice, but he doesn't really want to change them if possible. Maybe Freedom 2-2 is also a possibility)...

Is a 107" and cams with stock heads a waste of $$$ ?

Should he stay at 103" and just do cams and a good tune?

Or is 103" plus cams and a valve job (no porting) + cc'ing the heads for added compression a better option?

I'm not even sure what I'd do if it were my bike?

Thanks for any suggestions.

[Hossamania]

What's his budget? How does he want to ride it?
The 103 is a decent motor, cams and a tune would probably be the best bang for the buck.
Don't over cam the motor, get cams to match his riding style.
If he is not hot rodding, head work probably isn't necessary as far as money spent, unless a lot of miles on the motor and could benefit from a refresh.

[Ohio HD]

Truthfully he'd benefit greatly from at least a cleanup of the ports and a 1.9" intake valve put in the heads. The sheet below is a 107" with stock heads. Cams are Andrews 55's, and 10.5:1 compression. The stock heads really limit what the motor will make.

Improved flow by some head work will add HP as well as torque along the entire RPM range. If it were me, I'd wait until the head work is in the budget.

Also if someone besides me tuned the bike, maybe we would see 105hp or so.


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[Adam76]

What's his budget? How does he want to ride it?
The 103 is a decent motor, cams and a tune would probably be the best bang for the buck.
Don't over cam the motor, get cams to match his riding style.
If he is not hot rodding, head work probably isn't necessary as far as money spent, unless a lot of miles on the motor and could benefit from a refresh.

Thanks Hoss, riding style is mainly cruising but does get on it a bit to pass the odd truck on the highway.

His bike has only done 20,000 miles so probably doesn't "need" a freshen up unless it's just for increasing to a 107"

If it were cams only, I'd say maybe the S&S 583 ?

[Adam76]

Truthfully he'd benefit greatly from at least a cleanup of the ports and a 1.9" intake valve put in the heads.... The stock heads really limit what the motor will make.

Improved flow by some head work will add HP as well as torque along the entire RPM range. If it were me, I'd wait until the head work is in the budget.

Thanks Ohio,

I definitely agree that if going to 107 then headwork will really make it worth while.... but if staying at 103" ,  how much will headwork really add? If yes,  what would be a good choice of matching cams?

[boooby1744]

With that exhaust,it would be a good idea to lower overall gearing.

[Adam76]

With that exhaust,it would be a good idea to lower overall gearing.

Thanks, you mean at the primary or the rear sprocket?
What is the best gearing set up?

[Ohio HD]

Thanks Ohio,

I definitely agree that if going to 107 then headwork will really make it worth while.... but if staying at 103" ,  how much will headwork really add? If yes,  what would be a good choice of matching cams?

Improved flow helps with all motor sizes.

[Rockout Rocker Products]

Don't do like me & choose the 107.


 Then 110. 

[Hossamania]

For me, cam choice on a stock 103 is the CR 570-2. Good low and mid range, pulls nicely to the top.
Lots of good choices though.
And of course, a good tune is the key.

[Finn]

For me, cam choice on a stock 103 is the CR 570-2. Good low and mid range, pulls nicely to the top.
Lots of good choices though.
And of course, a good tune is the key.

"Hear, hear!"

[hrdtail78]

I would recommend 103 and head work.  Valve job, pocket porting and set the CC to what you want based on cam  choice.

Even if he isn't trying to bang of the rev limiter.  The worked heads will bring in lower RPM tq as well.

[harpwrench]

I definitely agree that if going to 107 then headwork will really make it worth while.... but if staying at 103" ,  how much will headwork really add? If yes,  what would be a good choice of matching cams?

Here's my 103 with S&S 570's and true duals at 30K, stock pistons, just added headwork, throttle body, and trimmed cyls to zero deck. 1.865/1.585 valves, compression 10.4

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[boooby1744]

With that exhaust,it would be a good idea to lower overall gearing.

Thanks, you mean at the primary or the rear sprocket?
What is the best gearing set up?

a 31 tooth Andrews front pulley will give you 3% increase. An Evolution industries 49 tooth clutch basket  ring gear is almost 6%. Depends how much you want to spend among things.

[Adam76]

I would recommend 103 and head work.  Valve job, pocket porting and set the CC to what you want based on cam  choice.

Even if he isn't trying to bang of the rev limiter.  The worked heads will bring in lower RPM tq as well.

Thanks, looks like headwork is more important than a few extra cubes.

With these softail true duals, what cams would you suggest be a good match?

Thanks

[Adam76]

With that exhaust,it would be a good idea to lower overall gearing.

Thanks, you mean at the primary or the rear sprocket?
What is the best gearing set up?

a 31 tooth Andrews front pulley will give you 3% increase. An Evolution industries 49 tooth clutch basket  ring gear is almost 6%. Depends how much you want to spend among things.

Thanks, it's hard to tell whether 3% or 6% is right when I've only ridden a bike with stock gearing..... Which one would you suggest? Thanks

[harpwrench]

My gut feeling is that if he doesn't want to ditch the fishtails then he would be happy with a 110 kit with S&S 585's, run the heads stock. GMR Steve did a bunch of them and felt it was the best bang for the buck. Made very strong torque in the low-mid range

[Adam76]

My gut feeling is that if he doesn't want to ditch the fishtails then he would be happy with a 110 kit with S&S 585's, run the heads stock. GMR Steve did a bunch of them and felt it was the best bang for the buck. Made very strong torque in the low-mid range

Thanks harpwrench,

The 110" kit makes good sense --  if doing a big bore kit.

But with only cams +/- headwork, what do you think of the S&S 583 cams?? Would they be a good match for the fishtails??

[harpwrench]

I wouldn't think so, it closes the intake pretty early and holds the exhaust open pretty late. So possibly cranking compression issues and amplified reversion effect if the fishtails don't play nice. Maybe I would would stick SE255's in it but I'm not an expert with softails or fishtails:)

[Ohio HD]

If you're just looking to keep it simple for now, I agree with keeping it a 103". As well if the heads aren't in the budget, stick an Andrews 48 in there. It won't be a power house, but it'll move pretty good.


https://harleytechtalk.com/htt/index.php/topic,103352.0.html

[Adam76]

If you're just looking to keep it simple for now, I agree with keeping it a 103". As well if the heads aren't in the budget, stick an Andrews 48 in there. It won't be a power house, but it'll move pretty good.


https://harleytechtalk.com/htt/index.php/topic,103352.0.html

Thanks Ohio,

If he stays at 103 but could afford mild headwork, what cams would you suggest other than the 48's ?
Cheers

[Adam76]

I wouldn't think so, it closes the intake pretty early and holds the exhaust open pretty late. So possibly cranking compression issues and amplified reversion effect if the fishtails don't play nice. Maybe I would would stick SE255's in it but I'm not an expert with softails or fishtails:)

OK thanks. I thought the 583 cams were specifically designed as a bolt in cam for the 103 ?? I could be wrong.
Cheers

[Ohio HD]

Thanks Ohio,

If he stays at 103 but could afford mild headwork, what cams would you suggest other than the 48's ?
Cheers

I don't see anything wrong with the sheet that harpwrench posted. The 570 cams will give a little broader range than the 585 cams will. As he stated the true duals with fishtails can cause havoc with the tune. But if that's what the guy wants, he may not see the full potential of what ever is used. The truth shows up in the tuning.

[Jim Bronson]

My gut feeling is that if he doesn't want to ditch the fishtails then he would be happy with a 110 kit with S&S 585's, run the heads stock. GMR Steve did a bunch of them and felt it was the best bang for the buck. Made very strong torque in the low-mid range

That's what I did to my dyna. It was a stock 88, so the bump in torque was major as long as I keep the revs up.

[harpwrench]

This is an interesting dyno thread with freedom fishtails, there's a couple video links to check and see if they're the same as yours

https://harleytechtalk.com/htt/index.php/topic,77305.msg851737.html#msg851737