98" cam Choice Help
Thread Starter
|
Road Warrior
Joined: Jan 2007
Posts: 1,415
Likes: 18
From: Belmont, MI
98" Cam Choice Help
Im looking for a little cam selection guidance. I want to try some different cams/pistons to bring the torque on sooner and drop my CR a bit. The reason for this is Im doing a lot more 2-up loaded touring and realize I wont always be able to get the 93 octane which is readily available in my area (MI).
Current build
98 at 10.5
9.17 corrected / 185.4ccp
CP 6cc pistons
well prepped heads (84cc 1.9 I/1.62 E w/grooves)
.030hg
Kury WT 26g cams
48mm HPI TB
TMAX AT
Timken conversion
Dark Horse prepped crank
3.37 gears.
This thing really screams from the mid to high rpms but Id prefer to have more torque in the lower rpm range. Its my personal opinion this build is better suited for a lighter bike or maybe a solo bagger not used primarily for 2-up touring.
My previous build (98) was with Andrews 37gs @ 9.7 and heads with mild (if any) cleanup and aftermarket stock valves. This was a real easy motor to live with as far as tune and lower octane when thats all that could be found and scooted along pretty good.
What cams would give me the characteristics of the 37's yet take advantage of the head work and throttle body? Im thinking I want to get the compression down into the 9.7-10 range.
Thanks,
Rick
Current build
98 at 10.5
9.17 corrected / 185.4ccp
CP 6cc pistons
well prepped heads (84cc 1.9 I/1.62 E w/grooves)
.030hg
Kury WT 26g cams
48mm HPI TB
TMAX AT
Timken conversion
Dark Horse prepped crank
3.37 gears.
This thing really screams from the mid to high rpms but Id prefer to have more torque in the lower rpm range. Its my personal opinion this build is better suited for a lighter bike or maybe a solo bagger not used primarily for 2-up touring.
My previous build (98) was with Andrews 37gs @ 9.7 and heads with mild (if any) cleanup and aftermarket stock valves. This was a real easy motor to live with as far as tune and lower octane when thats all that could be found and scooted along pretty good.
What cams would give me the characteristics of the 37's yet take advantage of the head work and throttle body? Im thinking I want to get the compression down into the 9.7-10 range.
Thanks,
Rick
Thread Starter
|
Road Warrior
Joined: Jan 2007
Posts: 1,415
Likes: 18
From: Belmont, MI
I'm currently running V&H Power Duals with 4" Jackpots. I've been through a couple of 2-1's and plan to stay with what I've got.
This is a mid to high rpm build, no getting around that. I'm just looking for some input on which route to go to turn this around. I'll make whatever changes are neccessary to accomplish my goal.
Rick
Seasoned HDF Member
Joined: Dec 2005
Posts: 5,465
Likes: 625
Earlier torque and lower compression generally don't go together. In order to bring the torque on earlier, you probably want to look at cams which close the intake valve earlier than what you currently have. An earlier intake close will raise you ccp. It's really not something you should be scared of as long as your tune is spot on with AFR AND timing. Are you good with tuning the timing aspect with you TMAX? If not, can you get it to someone that is.
As others suggest, probably want to talk to whoever worked on your heads. Need to understand what kind of lift you can get away with and what kind of flow you are getting to best match a cam.
I run the T-Man TR590's and get 100 tq and 2250 and 120 tq at 3000 in my 103". I'm right at 200 ccp. I'm a believer in T-Man. Give TR a call, he's a great guy to talk to.
Zach
As others suggest, probably want to talk to whoever worked on your heads. Need to understand what kind of lift you can get away with and what kind of flow you are getting to best match a cam.
I run the T-Man TR590's and get 100 tq and 2250 and 120 tq at 3000 in my 103". I'm right at 200 ccp. I'm a believer in T-Man. Give TR a call, he's a great guy to talk to.
Zach
98” at 10.5
9.17 corrected / 185.4ccp
CP 6cc pistons
9.17 corrected / 185.4ccp
CP 6cc pistons
Last edited by $tonecold; Sep 26, 2011 at 05:35 PM.
Stellar HDF Member
Joined: Feb 2010
Posts: 3,121
Likes: 489
From: sunny florida
I run the Cyclerama CR-575 cams , call Wes and talk to him , I'm over 100 trq at 2500 rpm's , but I have a 2-1 exhaust too that helps
Trending Topics
Thread Starter
|
Road Warrior
Joined: Jan 2007
Posts: 1,415
Likes: 18
From: Belmont, MI
I would say that some of these figures came from an engine calculator and there is nothing wrong with that. Bigboyzheadporting.com has a good one. It looks like you haven't actually measured your ccp unless you have a digital gauge. The dials are pretty acurate, but not within a tenth of a psi. If you haven't it would be a good thing to do and do a leak down while you're at it. The ccp number should be pretty close to what the calculator estimates. That said, I agree with Biggzed that the TR-590 would probably do for you what you desire. It will increase your dynamic compression at lower rpm by closing your intake sooner. This should bring your torque on at a lower RPM. You may see it hold on longer also which could translate into more HP. If you do drop your compression you might want to go with a cam that closes the intake at 40 degrees or sooner.
A lot of care was taken to make sure this build came out as expected and it did. It's a real screamer running through the gears which is a lot of fun but in reality it's a bagger and I'm starting to use it like one. I considerd going back to 37's and just adding 1.75 rockers and I still may but if I can find the right cam to give me the power in the same rpm band and take advantage of the head work and throttle body so much the better. It's not a high dollar thing to do this as I'll have the domes cut down a little to get my compression in line with what I need. What do the 590's like?
Another one I'm considering is Woods 5g. Has anyone run this?
Thanks,
Rick
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
6 Weirdest Harley-Davidsons Ever Sold to the Public
Verdad Gallardo
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
Thread Starter
|
Road Warrior
Joined: Jan 2007
Posts: 1,415
Likes: 18
From: Belmont, MI
Thanks,
Rick
Thread Starter
|
Road Warrior
Joined: Jan 2007
Posts: 1,415
Likes: 18
From: Belmont, MI
Earlier torque and lower compression generally don't go together. In order to bring the torque on earlier, you probably want to look at cams which close the intake valve earlier than what you currently have. An earlier intake close will raise you ccp. It's really not something you should be scared of as long as your tune is spot on with AFR AND timing. Are you good with tuning the timing aspect with you TMAX? If not, can you get it to someone that is.
As others suggest, probably want to talk to whoever worked on your heads. Need to understand what kind of lift you can get away with and what kind of flow you are getting to best match a cam.
I run the T-Man TR590's and get 100 tq and 2250 and 120 tq at 3000 in my 103". I'm right at 200 ccp. I'm a believer in T-Man. Give TR a call, he's a great guy to talk to.
Zach
As others suggest, probably want to talk to whoever worked on your heads. Need to understand what kind of lift you can get away with and what kind of flow you are getting to best match a cam.
I run the T-Man TR590's and get 100 tq and 2250 and 120 tq at 3000 in my 103". I'm right at 200 ccp. I'm a believer in T-Man. Give TR a call, he's a great guy to talk to.
Zach
One other problem I have. I can't leave anything alone and enjoy working on bikes and trying different things. My plan was to build a low comp 117" this winter before I got my wake up call. I need to put a new roof on my house before winter and as anyone can guess that ain't cheap.
Rick