Cams vs Piston Upgrade

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Nov 4, 2021 | 01:20 PM

GutzGufferson

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6th Gear

Joined: Aug 2021

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From: QC

Cams vs Piston Upgrade

Hello everyone.

Last year i upgraded the cams in my TC 88 Dyna. I installed S&S 509 cams. I like it so far.
This year I decided to upgrade the cylinder bore to 95". Will i have to change the cams or the 509 would be compatible with a 95? I'm a bit concerned.

Anyone have any clues on that matter?

Nov 4, 2021 | 04:09 PM

98hotrodfatboy

Seasoned HDF Member

Joined: Mar 2010

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From: Poolville

Yes you can.. But If your gonna do a big bore then go to 98", but to use higher lift cams you'll need head work which you should do then you can pick any cam and compression you want and the machine shop will do what is necessary to match everything based on your riding style and where you want your power.. Best to call one of the Indy's that support this site..

Nov 4, 2021 | 04:20 PM

strych9

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Joined: Aug 2017

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From: Omaha,NE

Depends on what you do with compression. If you go with higher compression your cam may not support it. The bore size isn't really relevant.

Nov 4, 2021 | 09:54 PM

TexasScooterTrash

Stellar HDF Member

Joined: Feb 2013

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From: Dallas, Texas

A 95" kit will work with the S&S cams as long as ya keep the compression ratio down to around 10:1. No head work needed.

Nov 5, 2021 | 07:24 AM

GutzGufferson

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6th Gear

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From: QC

Quote:

Originally Posted by TexasScooterTrash

A 95" kit will work with the S&S cams as long as ya keep the compression ratio down to around 10:1. No head work needed.

If my numbers are all good, the static compression would be at 10.03:1 and the corrected compression 9.87:1 (with the new pistons)

So i guess i'll be alright

Nov 5, 2021 | 11:28 AM

98hotrodfatboy

Seasoned HDF Member

Joined: Mar 2010

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From: Poolville

Yeah at, 10.03:1 your CCP is going to be up around 208 psi.. could be tuff tuning that one.. heat and detonation...

Nov 5, 2021 | 01:35 PM

GutzGufferson

Thread Starter

6th Gear

Joined: Aug 2021

Posts: 10

Likes: 1

From: QC

Quote:

Originally Posted by 98hotrodfatboy

Yeah at, 10.03:1 your CCP is going to be up around 208 psi.. could be tuff tuning that one.. heat and detonation...

So, should i replace the cams to avoid any problems in the future? If so, would you recommend S&S 310?

Last edited by GutzGufferson; Nov 5, 2021 at 02:01 PM.

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Nov 6, 2021 | 09:04 PM

sharkey

Grand HDF Member

Joined: May 2007

Posts: 3,870

Likes: 499

From: Alberta

S&S know their own products pretty good. Following their recommendations my wife’s stage 1 96” has 551 E-Z starts and my 103 has 583 E-Z starts. Neither has any headwork, both have extensive dyno tuning with the now obsolete SEPST and a top dyno operator. Both run smooth and strong. I’ve had a few 100+ HP HD’s; they were fun but didn’t suite our riding style. An awful lot of money can be spent performance building HD’s…know what your looking for before you spend much more. Just my opinion