Technical help selecting a cam needed
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Road Captain
Joined: Jun 2008
Posts: 550
Likes: 1
From: Arlington, TX
Technical help selecting a cam needed
Here is the build: 2006 Heritage EFI I am hoping some of you motor heads / technical guys could give me some well thought out input.
Bore = 3.905 95.81 ci
Heads = 78 cc's Milled .050, Ported, Polished, Stock stainless swirl polished exhaust valve, Oversize 1.90 stainless swirl polished intake valve
Head Gasket = .045 stock
Pistons = 10.25 high compression dome cast
High lift .64 S&S valve springs
650 feet above sea level
Compression releases
Arlen Ness Big Sucker
D&D Long Riders
T Max AutoTune
I have an SE-204, SE=211 and SE-251 on the shelf in the garage. The question is I want the power band 2200 to 5000 RPMS. Mostly in town riding only 15% 2 up riding. Should I use one of them or sell all of them and get something else
Bore = 3.905 95.81 ci
Heads = 78 cc's Milled .050, Ported, Polished, Stock stainless swirl polished exhaust valve, Oversize 1.90 stainless swirl polished intake valve
Head Gasket = .045 stock
Pistons = 10.25 high compression dome cast
High lift .64 S&S valve springs
650 feet above sea level
Compression releases
Arlen Ness Big Sucker
D&D Long Riders
T Max AutoTune
I have an SE-204, SE=211 and SE-251 on the shelf in the garage. The question is I want the power band 2200 to 5000 RPMS. Mostly in town riding only 15% 2 up riding. Should I use one of them or sell all of them and get something else
Elite HDF Member
Joined: Jul 2007
Posts: 3,891
Likes: 54
From: Mansfield, MA
My SE257 is a great high lift cam that works well with my High compression engine... It's a mid range rpm cam. It's no off the line drag monster, but tach up a bit and it takes off.
I'm no motor head.. That's just my experience
I'm no motor head.. That's just my experience
Tourer
Joined: Aug 2008
Posts: 483
Likes: 7
From: Harrisburg, NC
IMHO... I haven't done the math to see where your actual static compression will be, but I don't really like any of the SE cams you listed for your combination.
K.
HDF Community Team
Joined: Jun 2006
Posts: 12,791
Likes: 2,621
From: san antonio
In case you missed it; my response as posted in the Engine/Fuel/Intake/Exhaust section:
I get similar numbers in my calculator. The head/piston combination does not work; the CCR is unmanageable. Heads or pistons need to be replaced and pistons are the chepest way out. No need to 86 the pistons, just have the domed shaved off and make them flat tops.
Of the cams you listed, the SE204, with a .045 head gasket and a set of flat top pistons is the only one that comes close; static 9.9; corrected 9.29 and CCR 189psi. Corrected and CCR are great for the power band you are looking for but at 9.9 static, the SE204 can be a bitch to tune with the ground in advance.
I am curious about the 3.905" bore. IIRC, SE pistons are only available in one OS, .010". So, it would appear that your bore and pistons don't match up. If your bore is truly 3.905", the SE pistons will not work as the largest OS available is 3.885". You could use a set of 3.938" pistons and increase the displacement from 95" to 98", just need to hone your cylinders to fit.
In summary, regardless of bore, you need a set of flat top pistons, .030" head gasket and any cam of your choice with an intake close of 40*-44*. I like the Woods 5-6 or the TMan 590 or 625 since your heads can handle the lift.
You did not mention throttle body. With ported heads and long cams, you might benefit from a larger than stock or larger injectors.
I get similar numbers in my calculator. The head/piston combination does not work; the CCR is unmanageable. Heads or pistons need to be replaced and pistons are the chepest way out. No need to 86 the pistons, just have the domed shaved off and make them flat tops.
Of the cams you listed, the SE204, with a .045 head gasket and a set of flat top pistons is the only one that comes close; static 9.9; corrected 9.29 and CCR 189psi. Corrected and CCR are great for the power band you are looking for but at 9.9 static, the SE204 can be a bitch to tune with the ground in advance.
I am curious about the 3.905" bore. IIRC, SE pistons are only available in one OS, .010". So, it would appear that your bore and pistons don't match up. If your bore is truly 3.905", the SE pistons will not work as the largest OS available is 3.885". You could use a set of 3.938" pistons and increase the displacement from 95" to 98", just need to hone your cylinders to fit.
In summary, regardless of bore, you need a set of flat top pistons, .030" head gasket and any cam of your choice with an intake close of 40*-44*. I like the Woods 5-6 or the TMan 590 or 625 since your heads can handle the lift.
You did not mention throttle body. With ported heads and long cams, you might benefit from a larger than stock or larger injectors.
Last edited by djl; Nov 2, 2011 at 01:29 PM.
Seasoned HDF Member
Joined: Feb 2010
Posts: 5,618
Likes: 5,253
From: Green Country
Maybe you can find some information that may be of use to you here: http://www.nightrider.com/biketech/selectcam.htm
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