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Discussion Starter #1 (Edited)
Tell me what you think. I've mentioned it before, but now I'm really considering doing it. 999c intake cam paired to the 585 exhaust cams. I've attached what I believe is all the necessary information, unfortunately my knowledge and experience with different cams and choosing them is very limited. More intake duration than 585s along with more overlap, but not as much as the 999s. Please educate and criticize....

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Tell me what you think. I've mentioned it before, but now I'm really considering doing it. 999c intake cam paired to the 585 exhaust cams. I've attached what I believe is all the necessary information, unfortunately my knowledge and experience with different cams and choosing them is very limited. More intake duration than 585s along with more overlap, but not as much as the 999s. Please educate and criticize....

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Send this to @RACNRAY , he might be able to help!
 
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That is an interesting setup. Perhaps @Crestone would have time to plug into his model. The LSA I like, but I am not sure where the power band will shift without laying it out on paper. I have to dig up a spread sheet I used to use. The problem I see with the 999 intake is tuneablity, I wish we had access to the IVO/IVC table, then it would be a moot point. I think reversion might be an issue, which makes it a tuning issue as well.
 

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Discussion Starter #4
That is an interesting setup. Perhaps @Crestone would have time to plug into his model. The LSA I like, but I am not sure where the power band will shift without laying it out on paper. I have to dig up a spread sheet I used to use. The problem I see with the 999 intake is tuneablity, I wish we had access to the IVO/IVC table, then it would be a moot point. I think reversion might be an issue, which makes it a tuning issue as well.
The 999s were tough to tune down low but they came around after some effort. My limited knowledge says that it would be easier with less overlap.

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The 999s were tough to tune down low but they came around after some effort. My limited knowledge says that it would be easier with less overlap.

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Yes, it is the IVO that causes the idle problems, exhaust reversion. The 555’s gave me grief, could not get a stable start each and every time. So you will have the same issue with the 999’s. But as you point out, it might be more reasonable with the lower overlap. The power band should be nice.
 

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Discussion Starter #6
Yes, it is the IVO that causes the idle problems, exhaust reversion. The 555’s gave me grief, could not get a stable start each and every time. So you will have the same issue with the 999’s. But as you point out, it might be more reasonable with the lower overlap. The power band should be nice.
Well I'm all for finding out, especially since the heads will be off and I don't need a cam tool. It would be nice to find out before hand if I'd be wasting my time. The 999s were a lot of fun, but they faded as quick as they came on. A little less intensity in exchange for a bit more time at the top would be great.

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Im no I expert myself but I have been messing with performance engines a long time and I think to get the most out of that cam you need more compression. I also think driveability would be better with the 585.
 

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Very interesting, sounds like it would be worth a try if you're willing to be the guinea pig. As Craig said there could be an issue with tunability.
 

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Discussion Starter #11
Im no I expert myself but I have been messing with performance engines a long time and I think to get the most out of that cam you need more compression. I also think driveability would be better with the 585.
What makes you say that?

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Discussion Starter #12
Very interesting, sounds like it would be worth a try if you're willing to be the guinea pig. As Craig said there could be an issue with tunability.
I am. I've got a good 999 tune and a good 585 tune. I'm sure I can combine them. Do the numbers look good to you Ray?

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Discussion Starter #16
A stock 111 with 585s runs 7.75:1 dynamic cr.
My engine with the slightly later closing 999s is 8.26:1 dynamic cr.
What is the threshold and how is it determined?

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There again I'm not an expert. But I know from experience in building engines a 10:1 static compression engine won't run its best with that much duration and will probably have to turn some rpms to make power. All that being said my experience isn't in air cooled vtwins. I wouldn't think there would be a world of difference in the way it acts.
 

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Discussion Starter #18
There again I'm not an expert. But I know from experience in building engines a 10:1 static compression engine won't run its best with that much duration and will probably have to turn some rpms to make power. All that being said my experience isn't in air cooled vtwins. I wouldn't think there would be a world of difference in the way it acts.
Interesting. What you're saying falls in line with general consensus. Both the 999 and the 585 make the best power at about the same rpms.

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Discussion Starter #19
It's happening this weekend. 585 exhaust cams vs 999c intake cam.

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