quick question about cams in general
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Seasoned HDF Member
Joined: Mar 2008
Posts: 9,384
Likes: 1,776
From: Central Texas
quick question about cams in general
One time I read that preformance cams were a
trade off of wrere to put the power, take some
off of the top and place it on the bottom, or take
some off of the bottom and place it on the top.
Wouldn't stock cams give the best of both worlds,
for touring or does that idea go out the window
when the compression gets up around 10.5:1?
trade off of wrere to put the power, take some
off of the top and place it on the bottom, or take
some off of the bottom and place it on the top.
Wouldn't stock cams give the best of both worlds,
for touring or does that idea go out the window
when the compression gets up around 10.5:1?
Road Warrior
Joined: Jun 2007
Posts: 1,788
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From: Here
It's a combination of things really. When static compression is increased, the intake valve close typically needs to be delayed. That's how bolt in cams move the power curve around on an otherwise stock motor. Earlier close = increased ccp and a torque curve shifted to the left. Stock cams are pretty much limited to stock compression on a 96 or 103 due to the early intake close and short duration, and IMO a big bore upgrade should have a new cam installed. I know some other motorheads will chime in, but that's just the basics of it.
Outstanding HDF Member
Joined: May 2008
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Likes: 4
From: la
Thread Starter
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Seasoned HDF Member
Joined: Mar 2008
Posts: 9,384
Likes: 1,776
From: Central Texas
Thank you Matrix5 You just saved me a few more bucks.
I was thinking about putting my old stock 96 cam in with
my SE heads and SE pistons I guess I'll have to put up with
these SE 258 cams till tax refund time, maby longer if mama
out runs me to the bank LOL.
I was thinking about putting my old stock 96 cam in with
my SE heads and SE pistons I guess I'll have to put up with
these SE 258 cams till tax refund time, maby longer if mama
out runs me to the bank LOL.
Ultimate HDF Member
Joined: Feb 2007
Posts: 7,663
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From: Northeast Ohio
Actually you can increase hp and tq with the right cams in a stock engine. Then you do need to decide your riding style as to where you want the most gain, low end grunt or top end pulling. Static compression really identifies what cams to run as cams with long duration and overlap bleed off cylinder pressure, so the bigger the cam, the higher the static compression needs to be to keep cylinder pressures up and for the engine to retain some civility in the lower rpms.
Keep readin, become well educated regarding cams and how they interact with other items in the build. I have seen many more "over-cammed" engines with riders complaining of rideability issues than people complaining that they did not go big enough with the cam.
Keep readin, become well educated regarding cams and how they interact with other items in the build. I have seen many more "over-cammed" engines with riders complaining of rideability issues than people complaining that they did not go big enough with the cam.
Last edited by Dalton; Aug 31, 2009 at 07:19 PM.
Road Warrior
Joined: Nov 2007
Posts: 1,984
Likes: 7
And don't stop reading when you get to duration and lift and intake closing.
Check out, Lobe Center Angle (LCA), and, Lobe Seperation Angle (LSA). You will rarely see these things listed but you can figure them out from what is. They make up a huge part of the cam potential.
Check out, Lobe Center Angle (LCA), and, Lobe Seperation Angle (LSA). You will rarely see these things listed but you can figure them out from what is. They make up a huge part of the cam potential.
Road Captain
Joined: May 2009
Posts: 505
Likes: 2
Couple of points:
1. Stock cams are not the best - they're the cams the MoCo need to put in to get through EPA and noise tests.
2. Stock cams give a reasonable all round performance - but if you want more in the mid-top (like me) then losing a bit below 2500 is no big deal as I never run the engine there (except on my way to the higher revs)
3. Analyse where you might want more and where you might want to give some up, also analyse your riding style - what revs do you usually ride at.
1. Stock cams are not the best - they're the cams the MoCo need to put in to get through EPA and noise tests.
2. Stock cams give a reasonable all round performance - but if you want more in the mid-top (like me) then losing a bit below 2500 is no big deal as I never run the engine there (except on my way to the higher revs)
3. Analyse where you might want more and where you might want to give some up, also analyse your riding style - what revs do you usually ride at.
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Grand HDF Member
Joined: May 2008
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From: Newcastle, Ca.
Some good info above. This compliments a lot of what has been said about cams, choosing the right cam for your riding style, and the other components that make up a reliable build.
http://www.americanrider.com/output.cfm?id=1054045
http://www.americanrider.com/output.cfm?id=1054045
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