95" S&S 509 Build

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Feb 21, 2018 | 09:29 PM

muskwa

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From: Tar Island

95" S&S 509 Build

Long time lurker, first time poster.

My nephew found a completely stock 2003 low rider with a carb'ed 88. We are collecting parts to do a low-buck build. The cams are bought already as well as a Dynatek ignition. I have a line on 3.895" wiseco flat top pistons and will put it together with the stock heads and 0.030" head gaskets. Assuming zero deck height and 85cc heads the bigboyz calculator gives me 9.25:1 corrected compression ratio and 186.5 CCP @ 1000' ASL. We plan to use the stock carb re-jetted and the stock exhaust with the baffles drilled out. Will this combo perform on 94 octane gas? Will it require compression releases to start?

Thanks in advance,

Gavin

Feb 21, 2018 | 09:39 PM

98hotrodfatboy

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From: Poolville

If your numbers are correct....... No, you'll be fine and it should run fine even on 91 octane...

Feb 21, 2018 | 09:49 PM

muskwa

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From: Tar Island

At what CCP does hot starting become a problem? We plan to cc the heads and equalize the volumes by sanding, do you think it's worthwhile to bump the compression a bit?

Feb 22, 2018 | 06:16 AM

98hotrodfatboy

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From: Poolville

Noticeably above 190 ccp. I wouldn't do anything to the heads by sanding to create a smaller combustion chamber to increase compression.... That should be done by machining only.... That cam was designed for stock compression motors with the 18* ivc.... Always worthwhile to bump compression but not with that cam....

Feb 22, 2018 | 09:43 AM

djl

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From: san antonio

Quote:

Originally Posted by muskwa

Check the Wiseco piston PN and call Wiseco to verify that the piston has the 3mm oil control rings. Wiseco had an issue in 2016 with the 2mm oil control rings; the expander ends were cut at angle allowing them to overlap, loose tension and initiate oil consumption. Some motors were burning oil after 500 miles. Apparently this issue was limited to Wiseco's 98"/107" pistons; the 3.897" bore. May not be an issue but certainly worth checking out.

I don't disagree with 98hotrodfatboy but would install compression releases even at CCP less than 190psi. Just nice to have on hot restarts and will extend battery and starter life.

I run an all bore 107" motor in an '02 FLHT at 9.4 corrected and 186psi on 87 octane but do run higher octane in the hot south Texas summer months; July through September. Not sure if I need to, never tested it but it does get pretty dang hot down here; not taking the chance.

Feb 22, 2018 | 03:46 PM

muskwa

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From: Tar Island

Change o' plans

Thanks for the replies gents. Plans have changed and we will keep this build really low-buck by just installing the cams in the otherwise stock 88 as it doesn't really make sense to plan a big bore motor around such a small cam. Nephew can ride it while we make a better plan for a proper 98" build. Thanks for the advice re: compression releases, they will be part of the new and improved power scheme...

Feb 23, 2018 | 07:48 AM

Hillsidecycle.com

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If the cams had not already been purchased, an Andrews 21 now, and when pulling the trigger on the 98", 1.7 rockers on the intake side, work very well.
Scott