98" Cam choices
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Joined: May 2014
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From: Fort Frances
98" Cam choices
I know this is an old topic but bear with me. 99-06 cam choices are getting sparse, but plenty of people still riding 88’s and looking to upgrade. Hence this thread. I’m getting my 04 Road King Custom carb model bored to 98” this month, and the options for cams in stock are lesser and lesser with how old it is. Headwork will be done and a static CR of 10:1 or a bit higher is in order(CP +3cc pistons being used). Goal is CCP ~185(@1200’) at the end of the day with torque range being 2000rpm+(typical bagger street build). Of available cams I’ve come across on the market right now my list has come down to;
S&S 570
Reaper 574
TMan 580PS
Rocket Cams 554
The builder doing the heads and bore for me isn’t really partial to any of them, he pushed the Reaper 574 cams the most but I fear they’d be soft on the bottom? Other then past threads I can find I have little info, I live in rural Canada and tuners, builders and options in general are harder to acquire(or costly). Any help would be great. Hopefully this may help anybody else as well with new info on an old topic.
S&S 570
Reaper 574
TMan 580PS
Rocket Cams 554
The builder doing the heads and bore for me isn’t really partial to any of them, he pushed the Reaper 574 cams the most but I fear they’d be soft on the bottom? Other then past threads I can find I have little info, I live in rural Canada and tuners, builders and options in general are harder to acquire(or costly). Any help would be great. Hopefully this may help anybody else as well with new info on an old topic.
Seasoned HDF Member
Joined: Jun 2017
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From: Granville New York
Only one I can comment on is the s&s 570s. Had them in my 08 cvo road king 110. Had some headwork from hillside to go with them. Honestly I had an .040 head gasket and they were a little soft till 3k rpm and then they took off. I had a valve seal issue so when I put it back together I put .030 head gaskets in. I know that the thinner gasket only adds about .2 of compression but I think it got up enough to change the way the cams hit. They were no longer soft below 3k and still pulled hard to 5k rpm. I'm no pro by any means but I'm a firm believer that in order to get the best results you have to pay attention to all the small things...like a couple tenths of compression.
Grand HDF Member
Joined: Sep 2017
Posts: 4,359
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From: Dubuque, IA
You are doing this *** backwards.
You chose the cam first then decide what pistons and chamber volume is necessary to get the compression needed to run them at max performance and being "soft in the bottom" wouldn't be an issue.
I'm doing doing an 88 to 98 myself for someone and going with DM 598s at 11.2 using 6cc domed pistons. Looking to close in on 115hp with this build.
That said I'm not fond of those lackluster 574s.
I wouldn't run a CCP of less than 200psi. I'm running 212psi in my 107 build with Tman 590s. Plenty of torque from 2200rpm to 5800rpm where the up peaks.
The 570s are a good, versatile cam and the 580s are good as well. Again, don't be afraid of compression. Get a good tune.
You chose the cam first then decide what pistons and chamber volume is necessary to get the compression needed to run them at max performance and being "soft in the bottom" wouldn't be an issue.
I'm doing doing an 88 to 98 myself for someone and going with DM 598s at 11.2 using 6cc domed pistons. Looking to close in on 115hp with this build.
That said I'm not fond of those lackluster 574s.
I wouldn't run a CCP of less than 200psi. I'm running 212psi in my 107 build with Tman 590s. Plenty of torque from 2200rpm to 5800rpm where the up peaks.
The 570s are a good, versatile cam and the 580s are good as well. Again, don't be afraid of compression. Get a good tune.
Last edited by 60Gunner; Mar 9, 2023 at 06:04 PM.
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Joined: May 2014
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From: Fort Frances
You are doing this *** backwards.
You chose the cam first then decide what pistons and chamber volume is necessary to get the compression needed to run them at max performance and being "soft in the bottom" wouldn't be an issue.
I'm doing doing an 88 to 98 myself for someone and going with DM 598s at 11.2 using 6cc domed pistons. Looking to close in on 115hp with this build.
That said I'm not fond of those lackluster 574s.
I wouldn't run a CCP of less than 200psi. I'm running 212psi in my 107 build with Tman 590s. Plenty of torque from 2200rpm to 5800rpm where the up peaks.
The 570s are a good, versatile cam and the 580s are good as well. Again, don't be afraid of compression. Get a good tune.
You chose the cam first then decide what pistons and chamber volume is necessary to get the compression needed to run them at max performance and being "soft in the bottom" wouldn't be an issue.
I'm doing doing an 88 to 98 myself for someone and going with DM 598s at 11.2 using 6cc domed pistons. Looking to close in on 115hp with this build.
That said I'm not fond of those lackluster 574s.
I wouldn't run a CCP of less than 200psi. I'm running 212psi in my 107 build with Tman 590s. Plenty of torque from 2200rpm to 5800rpm where the up peaks.
The 570s are a good, versatile cam and the 580s are good as well. Again, don't be afraid of compression. Get a good tune.
Grand HDF Member
Joined: Sep 2017
Posts: 4,359
Likes: 1,219
From: Dubuque, IA
Agreed it may seem backwards. But all the cams I listed can be ran at 10:1 static which was the minimum goal(and that can be increased by shaving the heads up to 10.6:1). The CP +3cc pistons were chosen for this baseline, with 85cc chamber they make 10:1 static as the minimum. There’s no issue with choosing a minimum first knowing your components then the cam afterward. Lots of people change cams after builds are done, it’s the same difference. Although yes cams are usually chosen first. That being said anything north of 200ccp(@1200’) is a no go for me. Again I’m in rural Canada, 91 octane is the very best we can get up here and most likely 87 is most available while touring. Sure I could play with the timing when needed but it’s not ideal. I’d rather put myself in the ~190ccp area at my elevation to be safe where I ride the most. The 100/100 club is all im looking for here.
Good luck with the build.
The only 2 cams of those 4 I would run is the 570s and 580ps. The added exhaust duration of the 570s help with coo!ing
What exhaust are you running?
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Joined: May 2014
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From: Fort Frances
im not going to argue with your logic but just an fyi, 91 octane is all I run @ 212psi and I have no.pinging issues even on 95° days. But anything can ping if you lug it. A good tune is key.
Good luck with the build.
The only 2 cams of those 4 I would run is the 570s and 580ps. The added exhaust duration of the 570s help with coo!ing
What exhaust are you running?
Good luck with the build.
The only 2 cams of those 4 I would run is the 570s and 580ps. The added exhaust duration of the 570s help with coo!ing
What exhaust are you running?
Tourer
Joined: Oct 2005
Posts: 482
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I would use the T-man 580 and shoot for 200 cranking compression my guess is somewhere around 10:4 comp.
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Road Captain
Joined: Mar 2020
Posts: 659
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From: Sierra foothills
I know this is an old topic but bear with me. 99-06 cam choices are getting sparse, but plenty of people still riding 88’s and looking to upgrade. Hence this thread. I’m getting my 04 Road King Custom carb model bored to 98” this month, and the options for cams in stock are lesser and lesser with how old it is. Headwork will be done and a static CR of 10:1 or a bit higher is in order(CP +3cc pistons being used). Goal is CCP ~185(@1200’) at the end of the day with torque range being 2000rpm+(typical bagger street build). Of available cams I’ve come across on the market right now my list has come down to;
S&S 570
Reaper 574
TMan 580PS
Rocket Cams 554
The builder doing the heads and bore for me isn’t really partial to any of them, he pushed the Reaper 574 cams the most but I fear they’d be soft on the bottom? Other then past threads I can find I have little info, I live in rural Canada and tuners, builders and options in general are harder to acquire(or costly). Any help would be great. Hopefully this may help anybody else as well with new info on an old topic.
S&S 570
Reaper 574
TMan 580PS
Rocket Cams 554
The builder doing the heads and bore for me isn’t really partial to any of them, he pushed the Reaper 574 cams the most but I fear they’d be soft on the bottom? Other then past threads I can find I have little info, I live in rural Canada and tuners, builders and options in general are harder to acquire(or costly). Any help would be great. Hopefully this may help anybody else as well with new info on an old topic.
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Seasoned HDF Member
Joined: Mar 2021
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From: backwoods
My 95 and 98" have andrews 37G with .030 head gaskets and flat tops, with ported heads. 37 was the cam of choice on forums back then, I'd be tempted to go something with lower rpm. Maybe james .035 to lower compression a little, or even stock compression to avoid pinging.
That being said it does good too. Still riding it.
That being said it does good too. Still riding it.
Grand HDF Member
Joined: Sep 2017
Posts: 4,359
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From: Dubuque, IA
The newer Tman grinds aren't aggressive like some of the woods cams. There's really no reason to go with a cam that moves the torque to the left if run at the right compression. An IVC around 40ish with a CCP of 200psi is as far left as I would go.
The woods 6H would be good.
The woods 6H would be good.
Last edited by 60Gunner; Mar 10, 2023 at 04:44 AM.