Winter Upgrades

Reply Subscribe

Thread Tools

Search this Thread

Sep 8, 2018 | 06:51 PM

allthefineprint@gmail.com

Thread Starter

Novice

Joined: Aug 2018

Posts: 17

Likes: 0

From: Michigan

Winter Upgrades

winter work on my 04 road king - so I’m thinking about doing the s&s 97 big bore kit and a set of s&s 551 cams. I don’t want to have to port the heads - but am concerned about compression and top end work that might be involved.

what else do do I need to worry about?

(Seasoned auto mechanic and married to my service manual)

Sep 8, 2018 | 09:19 PM

allthefineprint@gmail.com

Thread Starter

Novice

Joined: Aug 2018

Posts: 17

Likes: 0

From: Michigan

Does this question need to be posted to another part of this forum?

Sep 8, 2018 | 09:24 PM

Nighthawk84

Intermediate

Joined: Jun 2018

Posts: 45

Likes: 6

From: Illinois

Right place, don’t expect many responses on weekends. I would definitely have the heads ported.

Sep 8, 2018 | 10:47 PM

jammerx

Stellar HDF Member

Joined: Aug 2007

Posts: 2,052

Likes: 341

From: Virginia Beach

You don't need to do the heads with the 551 cams. They are all torque down low. You will like them.

Sep 9, 2018 | 05:25 AM

2013_FLHTK

Road Warrior

Joined: Oct 2013

Posts: 1,399

Likes: 1,040

From: Seabrook, NH

Quote:

Originally Posted by allthefineprint@gmail.com

I think the lift is too much for your stock heads. Have your stock cylinders bored if you want to go with more displacement and definitely speak with one of the sponsors on this site. If it were my bike I'd go 98" with head work and the correct cam to fit your riding style. Worth every penny and not that expensive if you are doing the work yourself. FYI... I just installed a set of S&S 509 cams in my friends 2002 Heritage and he's thrilled with how much better it pulls when riding in the mountains.

Sep 9, 2018 | 06:31 AM

LazySundays

Road Captain

Joined: Jun 2013

Posts: 671

Likes: 168

From: Ontario, Canada

Quote:

Originally Posted by allthefineprint@gmail.com

You can't run the 551 with your valve springs. The 509 has almost the same specs but with lower lift.

That said, you're going to have the heads off and you're dealing with 14-15 year old parts. At the very least I'd get the valve seals replaced an the heads cleaned up. Might as well swap the springs to a set of higher lift ones while they're off anyways.

Might be worth posting in the engine forum, lots of experienced builders there that can give you more specific advice. I'm a mechanic but not an engine builder. I can put it all together but there are better people to help choose the parts.