117 build .. Throttle body advice needed

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Oct 22, 2019 | 02:52 PM

Bear1963

Thread Starter

3rd Gear

Joined: Mar 2019

Posts: 7

Likes: 1

From: United Kingdom

117 build .. Throttle body advice needed

Hi all,

I'm in the process of building a 117" Twin Cam Softail utilising most parts from a 2004 Fatboy donor bike. I bought a later 103" engine which has been the basis of a 117" build. Spec as follows:-

Ported 110 heads with 90.5cc volume
2.15” intake valves
1.625” exhaust valves
Suburban Speed 6.6cc domed piston kit
Static Comp 11.2:1
Corrected comp 9.76:1
T-Man 662-2 PS cams
Cometic 0.30 Head gaskets

The builder has recommended the SE 58mm throttle body with 5.3 injectors, but I'm using the wiring loom from the 04 Fatboy which I believe is incompatible with that part. I see that S&S do a 58mm body for the 00-05 Twin Cam motor. I've also been offered a secondhand 55mm S&S body.
I need advice on whether the 55mm with 5.3 injectors will be sufficient or should I buy the 58mm. If the latter is the case, is the 66mm worth considering? Are there any other options I should consider? I'm in the UK so my choices are really limited to S&S and Harley products as I don't want to be sending parts back across the pond if I have issues. Confused!!!

All help/insights gratefully received

Oct 22, 2019 | 09:04 PM

WKNDS

Grand HDF Member

Joined: Nov 2012

Posts: 4,997

Likes: 2,083

From: Newport,TN area

Sorry no answer for you, but rather a question.
You didn't list larger jugs? If you've got a 103 with
a 4.375-inch stroke, you'll need a 4.125" bore to
get to 117CI. This will require cracking the cases to
machine for larger spigot size. Just wondering if you're
going with the Axtell or Harley jugs...

Thanks,

T.

Oct 23, 2019 | 02:39 AM

Bear1963

Thread Starter

3rd Gear

Joined: Mar 2019

Posts: 7

Likes: 1

From: United Kingdom

Quote:

Originally Posted by WKNDS

Sorry, I I haven't listed the full build but just included the info I thought relevant to the question. I went with Harley jugs simply because I managed to pick a set up cheaply. Cases were machined and bottom end rebuilt with big lefty bearings both sides and a trued and welded crank.

Last edited by Bear1963; Oct 23, 2019 at 02:40 AM. Reason: Misspelled

Oct 23, 2019 | 05:46 AM

Madison Bill

Road Warrior

Joined: Oct 2014

Posts: 1,610

Likes: 1,134

From: Southconsin

More HP, More torque, Less garbage...Mikuni

Oct 23, 2019 | 05:56 AM

Screamin beagle

Seasoned HDF Member

Joined: Jun 2017

Posts: 5,315

Likes: 4,272

From: Granville New York

I don't know anything more than what I read. I've seen 124's setup with a 58mm and the 5.3 injectors so you're 117 should be well fed with that. For the injection stuff id stay with harley.

Oct 23, 2019 | 07:03 AM

WKNDS

Grand HDF Member

Joined: Nov 2012

Posts: 4,997

Likes: 2,083

From: Newport,TN area

Quote:

Originally Posted by Bear1963

Hi all,

I'm in the process of building a 117" Twin Cam Softail utilising most parts from a 2004 Fatboy donor bike. I bought a later 103" engine which has been the basis of a 117" build.
...snip...
I need advice on whether the 55mm with 5.3 injectors will be sufficient or should I buy the 58mm. If the latter is the case, is the 66mm worth considering? Are there any other options I should consider? I'm in the UK so my choices are really limited to S&S and Harley products as I don't want to be sending parts back across the pond if I have issues. Confused!!!

For the injector question, this calculator should help;
https://www.rbracing-rsr.com/fuelinjectors.htm

T.

Oct 23, 2019 | 03:13 PM

Bear1963

Thread Starter

3rd Gear

Joined: Mar 2019

Posts: 7

Likes: 1

From: United Kingdom

Quote:

Originally Posted by Screamin beagle

I don't know anything more than what I read. I've seen 124's setup with a 58mm and the 5.3 injectors so you're 117 should be well fed with that. For the injection stuff id stay with harley.

I'm leaning towards investing in a 58mm body unless anyone can give me an insight into how the 55mm will work with my setup. But do Harley produce a 58mm throttle body for use with the 00-05 Delphi system? If not then my choice is limited to the S&S part