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Rocker Arm Ratio

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92FXSTS

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I'm new to H-D EVO eng mods and was wondering if there are rocker arms with different ratios? Using different ratio rockers is an easy way to help performance on both Chev SB & BB engines and wondered if EVO's had the same options available. Thanks for any info
 
92FXSTS said:
I'm new to H-D EVO eng mods and was wondering if there are rocker arms with different ratios? Using different ratio rockers is an easy way to help performance on both Chev SB & BB engines and wondered if EVO's had the same options available. Thanks for any info
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I think Baisley and S&S make 1.7 ratio rocker arms. Jesell V twin makes other ratios as well (or used to). I'm not sure if they are for stock valve train set-ups. Mostly I think the big engine drag racers use them to compensate for altitude, temp. and other conditions (quicker than changing cams). A google search should turn something up.
 
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Breeze3at said:
I think Baisley and S&S make 1.7 ratio rocker arms. Jesell V twin makes other ratios as well (or used to). I'm not sure if they are for stock valve train set-ups. Mostly I think the big engine drag racers use them to compensate for altitude, temp. and other conditions (quicker than changing cams). A google search should turn something up.
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Thanks for the info, I'll do some googling now that I have a direction to go.

Something I forgot to ask above, do you or anyone know the ratio for the stock arms? Thanks again :)
 
remember,when changing r. ratio`s,you must recalculate & check valve to valve and valve to piston.i would run stock ratio rockers,only time we use higher ratio rockers is when a larger cam isnt avaliable
 
prodrag1320 said:
remember,when changing r. ratio`s,you must recalculate & check valve to valve and valve to piston.i would run stock ratio rockers,only time we use higher ratio rockers is when a larger cam isnt avaliable
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Thanks for that info, I'm use to doing that 8 times in a row on Chev SB & BB's. Do you know the stock Harley ratio? Thanks for the help
 
1:6 jumped into my head (evo) when I read your last request. The ratio is carried to 3 decimal places .625?, not positive. I'll look it up later if I remember.
 
Breeze3at said:
1:6 jumped into my head (evo) when I read your last request. The ratio is carried to 3 decimal places .625?, not positive. I'll look it up later if I remember.
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Once again, thanks for the info. I finally took some time to check around, with the info you had already given, and found a few different manufacturers.


FishHunter, Thanks for the follow-up info.
 
you a fisherman scott? you ever get down to indiana,ill take ya out on my NITRO (of corse) 150hp bass boat,very good bass fishing around here!!
 
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