[maubuchon]

My first post here, sorry if it mirrors similar posts, but looking for an essentially bolt-in gear drive cam for this setup that I have been running since new in 2000. Riding style is mostly two-up touring, but like to feel the power when I twist the grip at any common touring RPM range.

2000 Road King FLHR, 30k miles, runs well but occasional detonation and hot start kick-back
95" SE kit
SE heads, no compression releases
44mm SE CV carb and intake manifold
Borla slip-on mufflers with stock head pipes, but planning head pipes upgrade
SE ignition module
SE 203 cam, but looking to try something else in a gear drive cam

I have a few in mind, but want to hear what others think.
Thanks

(UPDATE: also has 10.5:1 SE forged dome pistons)

 

[Uncle Salty]

I run a Wood TW-6G in my 2004 Road King with compression right at 10/1. It's a "bolt in" cam with .510" lift. It has pretty decent low RPM manners and produces a nice flat torque curve from 2,500 to 5,500. I don't know if it will produce a substantial power increase over the 203 but that's what I run. A good 2-1 exhaust will help extract good performance. I have used a White Bros E series and currently have a D&D Fat Cat on it.

 

[Don Dorfman]

S&S 570G, reference "hippo" build on google search

 

[Uncle Salty]

S&S 570G, reference "hippo" build on google search

but looking for an essentially bolt-in gear drive cam for this setup that I have been running since new in 2000.

Is the S&S 570 a bolt-in cam? (for this combination)

 

[maubuchon]

S&S 570G, reference "hippo" build on google search

I have looked up the "hippo" build. I have read that I may or may not have to relieve the pistons for valve clearance. Until someone can guarantee that I don't have to do that, I don't want to take the risk. I'm trying to avoid tearing the top end down. I know I could test valve clearance without a tear down, but I would have to buy the cams first. I'd rather know that parts are compatible before buying them.

 

[Don Dorfman]

Until someone can guarantee...
Nope not from me. Your heads were milled .050 from HD day one with larger than stock valves and with a .030 head gasket, suggested, puts the valves closer yet. Let me be clear this is not caused by the .570 gross valve lift number but by the TDC lift numbers during overlap where both valves are open. You will have the heads off anyway to change the head gaskets, check piston to valve clearance. You may find, as I suspect just a small amount of dremel work on the intake side radially will be all you need to add. Really the 570g has just slightly more TDC lift than the 203s you already have, .187/.179 VS .178/.152, That considered you may be fine but wouldn't you feel better knowing for sure?
You say "compatible". What you appear to be looking for is a "bolt-in" cam. Even some of those would require checking, again it's not just having springs that will go there (yours do), it is TDC lift clearance piston to valve that needs checking. While your at it put in compression releases. Is it needed? No, however using them will increase the life of your starter drive and ring gear.

 

[maubuchon]

Don, I agree with everything you say, but I am trying to do this without removing the heads. This started out with me just thinking I better check my chain tensioners, and now I am already up to wanting cam plates and oil pump and gear drive and pushrod and lifter kits while I am in there. If I get into the top end, then I'll probably want compression releases, a port and polish, or new heads, forged pistons, or bigger bore, roller rockers, a different cam and on and on. Let me save the top end for later and just get away with a cam chest upgrade for now.

I was considering something like an Andrews 54G, .555 lift, .165/.158 TDC lift vs. .178/.152 for the 203 cam (so lower intake lift than the 203 cam), and I think 85 degree overlap vs 68 overlap for the 203 (so a little longer). Would that be a good choice?

 

[Don Dorfman]

That cam has always been a little sluggish down low at 95". If it is advanced (by offset key) 4deg it livens up some. Those heads flow 260 and are decent as-is. With a 1.94 intake and mild work they go right up to 280cfm.
Download and read S&S instructions on installing gear drives. To install them right it takes measurements, runout, and gear backlash. Oftentimes, not always followed, they need plus or minus gears and if over .002 runout they will make noise and this is the limit of allowed runout, at least that is all I tolerate.

 

[HDfatbagger]

30k miles in 22 years, why pay for all the cost of gears for 1500 miles per year,, install upgraded tensioner pads, maybe an upgraded oilpump.

 

[maubuchon]

That cam has always been a little sluggish down low at 95". If it is advanced (by offset key) 4deg it livens up some. Those heads flow 260 and are decent as-is. With a 1.94 intake and mild work they go right up to 280cfm.
Download and read S&S instructions on installing gear drives. ...

Well that's not good to hear about down low sluggishness for the Andrews 54 cams. My SE heads have been cleaned up of all the internal powder coat and casting imperfections, but not really ported I don't think. And yes I already know about the gear drive install requirements, and I can handle all that. I'll stay chain if I need to. I'm just still looking for cam recommendations for my current setup.

 

[maubuchon]

30k miles in 22 years, why pay for all the cost of gears for 1500 miles per year,, install upgraded tensioner pads, maybe an upgraded oilpump.

When I was younger I road all over the country. Now that I retired and have some cash to burn, I need a little project and something to get me fired up about motorcycling again. I don't mind modifying things to see if I can make an improvement. As long as I am in the cam chest, I wanted to see if a different cam would be an improvement. I don't recommend what I do as cost effective for everyone else.

 

[Don Dorfman]

Andrews 57g, same class as SE203, faster lobes more lift
S&S 570g more of a hot rod cam with added exhaust duration.
Both have TDC numbers close to the SE203 and the valve springs will accept that lift without danger of coil bind
In the day ignoring SE stage kits that 95" with those heads box stock and SE257 cams SE44 carb and thunderheader would make 110/105. Lots of fun. Needed a small dome piston however.

 

[maubuchon]

Andrews 57g, same class as SE203, faster lobes more lift

I don't see a 57g cam for Andrews, but possibly you mean the 37g. That cam looks close to the SE203.
(EDIT: There is a Andrews 57H cam for 2007-Later chain drive)

 

[maubuchon]

S&S 570g more of a hot rod cam with added exhaust duration.
Both have TDC numbers close to the SE203 and the valve springs will accept that lift without danger of coil bind
In the day ignoring SE stage kits that 95" with those heads box stock and SE257 cams SE44 carb and thunderheader would make 110/105. Lots of fun. Needed a small dome piston however.

Well I jumped into the can of worms and it's a whole new ballgame. I discovered that I in fact probably have the SE high compression forged dome pistons, deeper valve pockets, and which would put me at 10.5:1 compression. I started a new post with piston photos.

I also have the SE 7000 rpm ignition system installed by the dealer at the same time. I think that now I'd be back in the territory of the SE211, SE257 (but are not cam drive) and similar, and without further modification. I immediately thought about the hippo build which features the S&S 570 but which overviews at for 9:1 to 10:1 compression on their website, so not sure. Okay, now recommend.

 

[Don Dorfman]

Tman 590G, Andrews 67G, S&S 585G. None of these will have the manners down low, due to increased overlap, of the 203s but will offer 10+ hp increase, assuming good engine health and proper tune and pipe.

 

[maubuchon]

Tman 590G, Andrews 67G, S&S 585G. None of these will have the manners down low, due to increased overlap, of the 203s but will offer 10+ hp increase, assuming good engine health and proper tune and pipe.

Thanks for those recommendations. Keep in mind I have a carburetor and non-adjustable ignition though (although I see now that some adjustable ignition modules are available). Are there any cams available with good down low manners and compatible with 10:5 to 1 compression? Maybe a Feuling 543 or 574?

 

[Uncle Salty]

Before I started choosing a camshaft, I'd want to be sure of the actual compression ratio. I don't remember anyone claiming to run a SE 203 at a true 10.5 to 1 compression ratio. That would likely put your CCP over 205 PSI. CCP on my 95" Road King build is around 190 PSI and that's plenty for me considering the fuel quality now days.

 

[maubuchon]

Before I started choosing a camshaft, I'd want to be sure of the actual compression ratio. I don't remember anyone claiming to run a SE 203 at a true 10.5 to 1 compression ratio. That would likely put your CCP over 205 PSI. CCP on my 95" Road King build is around 190 PSI and that's plenty for me considering the fuel quality now days.

I just now for the first time ever checked my CCP with a new Harbor Freight compression tester, and an old Snap-On 308 tester. Both testers gave identical readings of 203 psi front, 206 psi rear. I am in California and only 91 octane available.

 

[maubuchon]

And it's possible I could be wrong about having a SE203, but that's just what I remember from 22 years ago. When I get inside the cam-chest, we will see.

 

[Don Dorfman]

It cranks right on the numbers for a 203. It will like the 45 intake close of the S&S 585G plus the added duration on the exhaust. Happy and a lot of fun. CCP will drop 10ish, not a bad thing. A Dtt TC88 would be a better ignition choice and timing could be tuned.