103 Compression Ratio

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Nov 21, 2007 | 10:35 PM

tattoo13

Thread Starter

Cruiser

Joined: Nov 2007

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103 Compression Ratio

I tryed to search for the answer but I can't find it.
I am looking for the compression ratio will be on a 103" kit for a 96" engine using the Screaming Eagle kit?

Nov 21, 2007 | 10:49 PM

Doc 1

Outstanding HDF Member

Joined: May 2007

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From: Florida

RE: 103 Compression Ratio

This depends on what cc the heads are....Harley heads fluctuate highly so a good educated guess for the 103 conversion with stock heads would be 9.5:1

Nov 27, 2007 | 06:35 AM

nidan

Road Warrior

Joined: Jun 2006

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From:

RE: 103 Compression Ratio

The SE catalog list the cast flat top pistons with the 103 /stock heads produces 10:1 compression . I believe these are the pistons used in the Stage II kit I'm running. ( page 18 of the Intake/Carb Engine/Engine component catalog )

As doc says , it isn't an absolute ..

Nov 27, 2007 | 12:40 PM

Harleypingman

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Joined: Apr 2006

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From: Roswell, GA

RE: 103 Compression Ratio

'07 and '08 police model Touring bikes have factory 103" engines; the specs for those show 9.6:1.

You can probably get your dealer to do a kit break-down comparing the Stage I and Stage II 103" kits for the 96 and see if the pistons are the same in both.

Nidan: Which SE parts catalog has the 10:1 info? I ask because I have the '08 SE Pro Racing Parts catalog and it doesn't give a CR for the cast flat-top 3 7/8" bore pistons, PN 21966-07.