what do you think I need for making high hp?
09-18-2009, 12:25 PM
#101
I have looked for data on the Brian Crower cams to do a more thorough analyis on them. However, the only information posted on their website is the duration, adv. duration and lift. Does anybody have data on the lobe separation angles for the BC cams that they can share??? If so, I'll compute the rest of the cam parameters and post them.
09-18-2009, 12:39 PM
#103
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I have looked for data on the Brian Crower cams to do a more thorough analyis on them. However, the only information posted on their website is the duration, adv. duration and lift. Does anybody have data on the lobe separation angles for the BC cams that they can share??? If so, I'll compute the rest of the cam parameters and post them.
09-18-2009, 12:49 PM
#105
I disagree.
Knowing the lobe separation angle and amouint of valve overlap still can be informative and help someone to select the approprate cam for them. For example, generally speaking, a 272 deg. cam with 30 degrees of valve overlap at TDC is going to idle better than a 272 deg. cam with 40 degrees of valve overlap. However, the cam with the greater overlap likely will provide better high end performance, assuming reversion does not become an issue.
09-18-2009, 12:57 PM
#106
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I agree.
I disagree.
Knowing the lobe separation angle and amouint of valve overlap still can be informative and help someone to select the approprate cam for them. For example, generally speaking, a 272 deg. cam with 30 degrees of valve overlap at TDC is going to idle better than a 272 deg. cam with 40 degrees of valve overlap. However, the cam with the greater overlap likely will provide better high end performance, assuming reversion does not become an issue.
I disagree.
Knowing the lobe separation angle and amouint of valve overlap still can be informative and help someone to select the approprate cam for them. For example, generally speaking, a 272 deg. cam with 30 degrees of valve overlap at TDC is going to idle better than a 272 deg. cam with 40 degrees of valve overlap. However, the cam with the greater overlap likely will provide better high end performance, assuming reversion does not become an issue.
09-18-2009, 12:58 PM
#107
spring dynamics are not something exclusive to jw.check and see if he winds his own springs,because this is the only way for him to provide some top secret formula.....even if he did (which he doesn't,he buy's them like you and me) he's following the same rules of metalurgy as everyone else.
so,now you tell me how he manufactures camblanks that only function with propietary springs and i'll give you a biscuit.
09-18-2009, 01:02 PM
#109
^^^^
Don't think so.
He is selecting springs in which the spring harmonics work well with his cam profiles. In other words, he has done the analysis to know which spring profile and spring rate works well accross his product line. If you randomly select some other spring without doing this analysis, you may get it right, you may get it wrong. Why is that so hard to understand???
Don't think so.
He is selecting springs in which the spring harmonics work well with his cam profiles. In other words, he has done the analysis to know which spring profile and spring rate works well accross his product line. If you randomly select some other spring without doing this analysis, you may get it right, you may get it wrong. Why is that so hard to understand???
Last edited by ttg35fort; 09-18-2009 at 01:10 PM.
09-18-2009, 01:14 PM
#110
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09-18-2009, 01:19 PM
#111
Maybe you don't realize it... But you have been coming across lately as a huge JWT fanboy/nutswinger. Sorry if that offends you. I thought it was worth pointing out that not everybody (including some of the top shops in this community) are convinced of JWT's superiority and that some of us have a problem with Jim's shady business associations (and therefore won't buy or support his products).
Last edited by RudeG_v2.0; 09-18-2009 at 01:29 PM.
09-18-2009, 01:20 PM
#112
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^^^^
Don't think so.
He is selecting springs in which the spring harmonics work well with his cam profiles. In other words, he has done the analysis to know which spring profile and spring rate works well accross his product line. If you randomly select some other spring without doing this analysis, you may get it right, you may get it wrong. Why is that so hard to understand???
Don't think so.
He is selecting springs in which the spring harmonics work well with his cam profiles. In other words, he has done the analysis to know which spring profile and spring rate works well accross his product line. If you randomly select some other spring without doing this analysis, you may get it right, you may get it wrong. Why is that so hard to understand???
you should be angry with him for trying to sell you magic beans
09-18-2009, 01:27 PM
#113
You said "a camshaft that measures .485 lift but achieves an actual .520 lift?"
Is .520 lift not greater than .485 lift????????
Well, ballpark information is better than nothing.
Maybe you don't care about these parameters. That's fine.
But go outside our little VQ community, and yes, there is A LOT of evidence that valve overlap and valve separation angle do make a difference on a motors performance, even when all other things are equal. The guys who really know their **** take all of this into consideration when building a motor.
Is .520 lift not greater than .485 lift????????
Maybe you don't care about these parameters. That's fine.
But go outside our little VQ community, and yes, there is A LOT of evidence that valve overlap and valve separation angle do make a difference on a motors performance, even when all other things are equal. The guys who really know their **** take all of this into consideration when building a motor.
09-18-2009, 01:31 PM
#114
I thought it was pretty clear what I meant.
Maybe you don't realize it... But you have been coming across lately as a huge JWT fanboy/nutswinger. Sorry if that offends you. I thought it was worth pointing out that not everybody (including some of the top shops in this community) are convinced of JWT's superiority and that some of us have a problem with Jim's shady business associations (and therefore won't buy or support his products).
Maybe you don't realize it... But you have been coming across lately as a huge JWT fanboy/nutswinger. Sorry if that offends you. I thought it was worth pointing out that not everybody (including some of the top shops in this community) are convinced of JWT's superiority and that some of us have a problem with Jim's shady business associations (and therefore won't buy or support his products).
1. He publishes alot of information about his cams, which others don't.
2. For the same duration, those cams typically provide greater lift. Lift is important.
3. I always note that they are limited to about 7500 rpm and that if you want something to go beyond that, look at GTM and BC cams.
4. Other than JWT cams and an oil spacer, I don't have anything else that is JWT. In fact, I have a GTM motor and a GTM turbo kit. I probably use the term GTM in this forum alot more than JWT.
Last edited by ttg35fort; 09-18-2009 at 01:37 PM.
09-18-2009, 01:40 PM
#115
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09-18-2009, 01:43 PM
#116
^^^^
Don't think so.
He is selecting springs in which the spring harmonics work well with his cam profiles. In other words, he has done the analysis to know which spring profile and spring rate works well accross his product line. If you randomly select some other spring without doing this analysis, you may get it right, you may get it wrong. Why is that so hard to understand???
Don't think so.
He is selecting springs in which the spring harmonics work well with his cam profiles. In other words, he has done the analysis to know which spring profile and spring rate works well accross his product line. If you randomly select some other spring without doing this analysis, you may get it right, you may get it wrong. Why is that so hard to understand???
Let's see...You are an attorney by trade IIRC and go-fast is a renowned engine builder beyond just the VQ platform with a waiting list of customers. Now who should we listen to and believe?
I tried to warn you about continuing to argue with go-fast. Keep arguing with an expert in this industry and dig that hole deeper.
09-18-2009, 01:48 PM
#117
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Let's see...You are an attorney by trade IIRC and go-fast is a renowned engine builder beyond just the VQ platform with a waiting list of customers. Now who should we listen to and believe?
I tried to warn you about continuing to argue with go-fast. Keep arguing with an expert in this industry and dig that hole deeper.
09-18-2009, 01:49 PM
#118
Hi Raj, you didn't look good enough. 
http://www.jimwolftechnology.com/wol...INCL_REVUP.pdf
In the lower right hand boxes for each of the C2, C8, C9 and C1HR cams, it states: "MUST USE JWT SPRINGS". The box for the S2 cams does not state ths.
I spoke with Jim Wolf months ago about the C8 cams. I asked him whether it would be worthwhile to use stiffer springs with the cams to get more RPM out of them. He specifically told me not to because his springs were designed to be harmonically balance with his cams. He said using other springs probably would be counter-productive.
http://www.jimwolftechnology.com/wol...INCL_REVUP.pdf
In the lower right hand boxes for each of the C2, C8, C9 and C1HR cams, it states: "MUST USE JWT SPRINGS". The box for the S2 cams does not state ths.
I spoke with Jim Wolf months ago about the C8 cams. I asked him whether it would be worthwhile to use stiffer springs with the cams to get more RPM out of them. He specifically told me not to because his springs were designed to be harmonically balance with his cams. He said using other springs probably would be counter-productive.
For S2 cams, it does not say that they REQUIRE stock cams nor does it say that you cannot use JWT springs.
I am dubious that the springs are part of the design for eliminating unwanted harmonics. As long as the spring helps the entire valvetrain to stay in contact with one another, I think they are serving their purpose - no more, no less. I respect what Jim Wolf has to say, but I won't believe it just because he feels it is "probably" true especially when he has a product to sell.
Here is a well written site on cam analysis and cam springs:
http://www.tildentechnologies.com/Te...CamBasics.html
http://www.tildentechnologies.com/Te...amSprings.html
Here is what they have to say about valve springs in relation to cams with higher lift:
Higher engine speeds require stiffer springs, but higher lifts lead to higher spring forces, so weaker springs can be used.
09-18-2009, 01:51 PM
#119
Although a spring has a spring constant K, under dynamic conditions the spring is not so constant. E.g.,
http://www.youtube.com/watch?v=i_Npz...om=PL&index=16
If there is a spring harmonic which causes the spring to compress right about the time the top of the lobe is coming across the bucket, you are going to have a problem.
09-18-2009, 01:52 PM
#120
Let's see...You are an attorney by trade IIRC and go-fast is a renowned engine builder beyond just the VQ platform with a waiting list of customers. Now who should we listen to and believe?
I tried to warn you about continuing to argue with go-fast. Keep arguing with an expert in this industry and dig that hole deeper.