Big bore, not so big.....
Thread Starter
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Tourer
Joined: Sep 2010
Posts: 436
Likes: 3
From: Norway
Big bore, not so big.....
So....
On my last bike, a 2008 97" FLSTSB, I considered doing the stage 4 S&S 106". I never got that far before I changed to my current bike.
I now have a 2014103" FXDF with SE204 cams.
The only guys building motors in my area builds S&S engines.
So they gave me an offer on the stage 4 S&S 106" on my last bike, and claimed 105-115 BHP and about 110 ft/lbs. This would cost me $5600 ( keep in mind that this is in Norway, so everything is expensive up here.
The thing is... Now I have a 103", and even though I haven't dynoed it yet, I'm guessing I'm close to 90 hp already. So the $5600 won't give me the same amount of increase as it would on the 97".
What other options do I have to get some more omph out of this bike. Do I have to bore the case aswell? I know they do a 124" but that costs over $9000 and I'm not willing to spend that kind of cash... Is 106"/107" the biggest you can go on these engines? That's barely larger than stock :S
On my last bike, a 2008 97" FLSTSB, I considered doing the stage 4 S&S 106". I never got that far before I changed to my current bike.
I now have a 2014103" FXDF with SE204 cams.
The only guys building motors in my area builds S&S engines.
So they gave me an offer on the stage 4 S&S 106" on my last bike, and claimed 105-115 BHP and about 110 ft/lbs. This would cost me $5600 ( keep in mind that this is in Norway, so everything is expensive up here.
The thing is... Now I have a 103", and even though I haven't dynoed it yet, I'm guessing I'm close to 90 hp already. So the $5600 won't give me the same amount of increase as it would on the 97".
What other options do I have to get some more omph out of this bike. Do I have to bore the case aswell? I know they do a 124" but that costs over $9000 and I'm not willing to spend that kind of cash... Is 106"/107" the biggest you can go on these engines? That's barely larger than stock :S
Ultimate HDF Member
Joined: Apr 2008
Posts: 5,384
Likes: 12
From: Out on Deranged
No your 103 does not give 90 HP, more like 78 to 80 stock and add a few ponies , generally 5 maybe with those cams. A stock 96" engine gives 72 to 74 HP.
An S&S engine is a huge upgrade, being that your looking at a stage IV head job you will be upgrading to a larger throttle body to keep your fuel flow up with your intake demands. So what I really want to say here is, IMO you should inquire about a full on 124" upgraded engine from S&S. I believe you may only need an extra thousand to put it together. Then you will have the bike of your dreams including 120+ HP & TQ!!!
To QC's remark anything HD makes has to be street legal and conform to emissions law so performance wise forget the 110. I bet I would leave any HD 110 in the dust with my 107 stII from fuel moto. But a 110 does not fit into a present day six speed crankcase without boring because the cylinder walls become too thin to keep cool given that these are air cooled bikes. With a 110 we need thicker jug walls to absorb and help dissipate heat hence the case boring.
An S&S engine is a huge upgrade, being that your looking at a stage IV head job you will be upgrading to a larger throttle body to keep your fuel flow up with your intake demands. So what I really want to say here is, IMO you should inquire about a full on 124" upgraded engine from S&S. I believe you may only need an extra thousand to put it together. Then you will have the bike of your dreams including 120+ HP & TQ!!!
To QC's remark anything HD makes has to be street legal and conform to emissions law so performance wise forget the 110. I bet I would leave any HD 110 in the dust with my 107 stII from fuel moto. But a 110 does not fit into a present day six speed crankcase without boring because the cylinder walls become too thin to keep cool given that these are air cooled bikes. With a 110 we need thicker jug walls to absorb and help dissipate heat hence the case boring.
Last edited by maddghost; Sep 14, 2014 at 01:49 PM.
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
A well done 106" should put you around 110/115 which is no slouch! If you bore out your cases then go 117" but the cost does start to ratchet up to kinda/almost justifying a 124" 
Just remember to check your crank run out before buying parts to see how healthy your crank is for a 106" build. If you go 117", you will be splitting the cases anyway so get your crank fixed up while you are there.
Just remember to check your crank run out before buying parts to see how healthy your crank is for a 106" build. If you go 117", you will be splitting the cases anyway so get your crank fixed up while you are there.
Last edited by HD Pilot; Sep 14, 2014 at 03:11 PM.
Thread Starter
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Tourer
Joined: Sep 2010
Posts: 436
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From: Norway
I'm sure I've seen dynocharts of the New 103" with se204 and 2-1 exhaust make 90 HP. Might be a very optimistic dyno though. I hope I dont have 90 HP, cos then 110hp cant be enough hehe...
New Engine is not an option since we have pretty strickt rules over here. Need the original enginenumber.
New Engine is not an option since we have pretty strickt rules over here. Need the original enginenumber.
Ultimate HDF Member
Joined: Apr 2008
Posts: 5,384
Likes: 12
From: Out on Deranged
Another thing I would like to say though is people have been making 110 to 120 #'s with harley bikes since ....forever even when the blocks weren't so big, my meaning is with the right headwork, cams + throttle body, the right components, high compression and a good dyno a good builder can make a 103 fly! But if your builder only slaps S&S parts out of the box and onto your bike is one thing. But if he does machineing and proper headwork that is quite another.
Last edited by maddghost; Sep 14, 2014 at 04:13 PM.
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Road Master
Joined: Dec 2009
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From: Coweta, Oklahoma
I'm sure I've seen dynocharts of the New 103" with se204 and 2-1 exhaust make 90 HP. Might be a very optimistic dyno though. I hope I dont have 90 HP, cos then 110hp cant be enough hehe...
New Engine is not an option since we have pretty strickt rules over here. Need the original enginenumber.
New Engine is not an option since we have pretty strickt rules over here. Need the original enginenumber.
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Thread Starter
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Tourer
Joined: Sep 2010
Posts: 436
Likes: 3
From: Norway
Are those the Stock HD103" heads? If so, the Stock 103" With SE204s make some impressive number. This confuses me.
A friend of mine bought a New Street Bob when I bought my Fat Bob. I went With cams, he didn't. There is a difference, but by no mean a huge difference....
Stellar HDF Member
Joined: Jan 2013
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From: Rouses Point, N.Y.
my Hillside 107 has beaten a standard vrod twice. have not gone against a muscle yet. correctly setup 107@ 10.8-11.1 with some stage IV high flowing heads with correct cams and a HPI 55mm throttle body. plus a good clutch and properly tuned will get you up into the 120 range that should impress you.