HQ Cam question?
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Road Captain
Joined: Apr 2006
Posts: 628
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From: Wichita but from Tulsa
HQ Cam question?
I was viewing the specs on cams and notice that HQ always has the Exhaust lift about .030 less than the intake. A lot of the cams are straight across. I am looking at cams within the .575 to .600 intake lift when I do my build. I know some of you have been researching the hell out of this stuff so any info would be appreciated.
Road Warrior
Joined: Jun 2006
Posts: 1,797
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From: NH
RE: HQ Cam question?
ORIGINAL: 77Tulsa
I was viewing the specs on cams and notice that HQ always has the Exhaust lift about .030 less than the intake. A lot of the cams are straight across. I am looking at cams within the .575 to .600 intake lift when I do my build. I know some of you have been researching the hell out of this stuff so any info would be appreciated.
I was viewing the specs on cams and notice that HQ always has the Exhaust lift about .030 less than the intake. A lot of the cams are straight across. I am looking at cams within the .575 to .600 intake lift when I do my build. I know some of you have been researching the hell out of this stuff so any info would be appreciated.
Hope this helps.
Denis
Ultimate HDF Member
Joined: Feb 2006
Posts: 5,939
Likes: 3
From: TX
RE: HQ Cam question?
HQ uses an asymetrical lobe design on their cams, menaing that that the lobes are physically different shape and size. Most other vendors use the same lobe shape & size for both intake and exhaust and simply adjust the orientation. Using the asymetrical design is obviously more expensive from a manufacuting perspective and makes designing the grinds more complex, but for someone that knows what they are doing, it opens the door to increased creativity and conceivably better results.
Regarding selection, the answer has more to do with the "whole package" and just one piece.
I'd suggest a call to Doug, in order to get the best answer and recommendation. He can also explain the lobe design much better!
Regarding selection, the answer has more to do with the "whole package" and just one piece.
I'd suggest a call to Doug, in order to get the best answer and recommendation. He can also explain the lobe design much better!
Elite HDF Member
Joined: Mar 2006
Posts: 4,722
Likes: 5
From: Biddeford, Maine
RE: HQ Cam question?
From what Doug told me, the cam design that he uses allows the cams to make better flatter torque curves and at the sametime make higher hp numbers.
He got very technical with me when we were discussing the differences between the Andrews 26G's I had and the HQ0034G's I was getting ready to install.
It is best to call him and talk to him yourself, he is very good at explaining things and will help you in the right direction for your build.
Steve
He got very technical with me when we were discussing the differences between the Andrews 26G's I had and the HQ0034G's I was getting ready to install.
It is best to call him and talk to him yourself, he is very good at explaining things and will help you in the right direction for your build.
Steve
Banned
Joined: Jan 2006
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From:
RE: HQ Cam question?
As a general rule, every cylinder head and intake/exhaust tract is "Manufacturer specific" and has its own inherent design flaws. I am not sure, but on a Harley, maybe the intake side is more restricted than the exhaust. If so, that would explain why the cam would need more lift and duration on the intake side to make up for design shortcomings in the intake manifold/runner/valve pocket/etc. Also, different engines respond differently to more lift/duration on the intake/exhaust. Fact is, it is more expensive to make a dual pattern cam, it will be more versatile, and Doug knows his stuff!
nogood o~`o
nogood o~`o
Road Warrior
Joined: Feb 2007
Posts: 1,749
Likes: 4
From: Augusta, Ga.
RE: HQ Cam question?
The HD exhaust port doesn't require as much lift as the intake does to exhale the spent gas.
A lot of cams are the same but it's unnecessary according to some.....
I went with Dougs cam after the recommendations of two of the above posters and after talking to him one day.
A lot of cams are the same but it's unnecessary according to some.....
I went with Dougs cam after the recommendations of two of the above posters and after talking to him one day.
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