Bigger Cam / Idle question...
Thread Starter
Safety Car
Joined: Sep 2003
Posts: 3,599
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From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Bigger Cam / Idle question...
For those who run bigger cams - what do you have your "target" or "desired" idle RPM programmed to?
I'm running a .580 lift / 240 @ .050 duration cam (112 + 4, 16* overlap) in my 383. Target idle is currently programmed at 850 rpm, but it seems low to me. Just curious where others are at.
Thanks!
Dan
I'm running a .580 lift / 240 @ .050 duration cam (112 + 4, 16* overlap) in my 383. Target idle is currently programmed at 850 rpm, but it seems low to me. Just curious where others are at.
Thanks!
Dan
Former Vendor
Joined: Jun 2001
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From: St Marys PA
Originally Posted by byebyeL98
For those who run bigger cams - what do you have your "target" or "desired" idle RPM programmed to?
I'm running a .580 lift / 240 @ .050 duration cam (112 + 4, 16* overlap) in my 383. Target idle is currently programmed at 850 rpm, but it seems low to me. Just curious where others are at.
Thanks!
Dan
I'm running a .580 lift / 240 @ .050 duration cam (112 + 4, 16* overlap) in my 383. Target idle is currently programmed at 850 rpm, but it seems low to me. Just curious where others are at.
Thanks!
Dan
Thread Starter
Safety Car
Joined: Sep 2003
Posts: 3,599
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From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Thanks Ski / Zix - I was thinking along those lines as well, for just the reasons you listed. It idles just a little bit too rough at 850 rpm.
Race Director
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From: The Top of Utah
Originally Posted by byebyeL98
I'm running a .580 lift / 240 @ .050 duration cam (112 + 4, 16* overlap) in my 383.
Thanks!
Dan
Thanks!
Dan
RACE ON!!!
Le Mans Master
Joined: May 2000
Posts: 7,033
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Originally Posted by CFI-EFI
Exactly what do you mean by this? I do not believe you if you are saying you have 16° of overlap. And I really don't think you are. But what ARE you saying?
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Thread Starter
Safety Car
Joined: Sep 2003
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From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Sorry if I gave the wrong information. What I was trying to say (and obviously did not do so correctly), was that the cam has a 112* lobe separation angle with 4* advance built in.
Based on CFI's comment, I may have miscalculated the overlap figure from my cam card. :o All figures were hand written on the card, so I'll need to check with the manufacturer for the specs (Howard's Cams), and I'll ask them for a target idle while I'm at it.
Thanks!
Based on CFI's comment, I may have miscalculated the overlap figure from my cam card. :o All figures were hand written on the card, so I'll need to check with the manufacturer for the specs (Howard's Cams), and I'll ask them for a target idle while I'm at it.
Thanks!
Race Director
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From: The Top of Utah
Originally Posted by 86VX1
have you tried asking the people that sold you the grind?
Originally Posted by byebyeL98
I'm running a .580 lift / 240 @ .050 duration cam (112 + 4, 16* overlap)
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Le Mans Master
Joined: Jul 1999
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From: Phoenix AZ
Originally Posted by CFI-EFI
Nobody has sold ME anything.
I'm good up until, "(112 + 4, 16* overlap)". Then I ASSUME "112" is the lobe center displacement angle? Does "+4" mean that the cam was advanced 4°? Was that 4° ground in at manufacture? Or added during installation? OR both? I would prefer to not even speculate on "16*". How about it, 86VX1, what's it all mean?
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I'm good up until, "(112 + 4, 16* overlap)". Then I ASSUME "112" is the lobe center displacement angle? Does "+4" mean that the cam was advanced 4°? Was that 4° ground in at manufacture? Or added during installation? OR both? I would prefer to not even speculate on "16*". How about it, 86VX1, what's it all mean?
RACE ON!!!
86VX1 didn't start the thread he just wanted to know if ByeByeL98 asked the cam manufacturer about it
ByeByeL98 started the thread...you should be asking him what it all means.
Thread Starter
Safety Car
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From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Originally Posted by Zix
ByeByeL98 started the thread...you should be asking him what it all means.
(and I now FULLY understand the ramifications of NOT posting clearly
)
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From: The Top of Utah
Originally Posted by Zix
Okay, now you're confusing me!
86VX1 didn't start the thread he just wanted to know if ByeByeL98 asked the cam manufacturer about it
86VX1 didn't start the thread he just wanted to know if ByeByeL98 asked the cam manufacturer about it
ByeByeL98,
Now that you explain what you were doing, your arithmetic is probably correct..., for the overlap at .050" lift. However, gases start flowing LONG before the valves get to .050" lift, and makes that a meaningless number. If that is what you did, that 16° number, is as meaningful as if it were expressed in furlongs per fortnight. If you re-figure from the "advertised" event points. you will come up with a worthwhile number.
Also, for the record, I was called to the front door and although I posted after the number 10 and 11 posts, I hadn't seen them until after I posted.
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Le Mans Master
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Originally Posted by CFI-EFI
Nobody has sold ME anything.
I'm good up until, "(112 + 4, 16* overlap)". Then I ASSUME "112" is the lobe center displacement angle? Does "+4" mean that the cam was advanced 4°? Was that 4° ground in at manufacture? Or added during installation? OR both? I would prefer to not even speculate on "16*". How about it, 86VX1, what's it all mean?
RACE ON!!!
I'm good up until, "(112 + 4, 16* overlap)". Then I ASSUME "112" is the lobe center displacement angle? Does "+4" mean that the cam was advanced 4°? Was that 4° ground in at manufacture? Or added during installation? OR both? I would prefer to not even speculate on "16*". How about it, 86VX1, what's it all mean?
RACE ON!!!
Yea we're pretty close on the unaddable math. I won't guess either but these are the numbers that I expected what they meant. 112, put in 4*(doesn't matter witch way) but you can't add it to 116.
CFI- you actually have enough knowledege in your melon to help people out. You can read the errors as much as I can, so just help them out.
Am I wrong or not?
Race Director
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From: The Top of Utah
Originally Posted by Dominic Sorresso
Overlap is based on the .006" lift numbers. What are they for this cam?
Originally Posted by hippy
CFI- you actually have enough knowledege in your melon to help people out. You can read the errors as much as I can, so just help them out.
Am I wrong or not?
Am I wrong or not?
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Thread Starter
Safety Car
Joined: Sep 2003
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From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Originally Posted by CFI-EFI
No fair! I asked first.
I couldn't start to help until I understood what he was saying, or how he derived it. It looked to me, that somehow he thought he'd altered his LSA, and that he was saying that he had 16° of overlap. It wasn't until more info was tossed around, that I figured the overlap number was at .050". Although I STILL haven't seen a confirmation that is what happened, I do believe it, until told differently. Sorry, I was so slow to "read between the lines".
RACE ON!!!
I couldn't start to help until I understood what he was saying, or how he derived it. It looked to me, that somehow he thought he'd altered his LSA, and that he was saying that he had 16° of overlap. It wasn't until more info was tossed around, that I figured the overlap number was at .050". Although I STILL haven't seen a confirmation that is what happened, I do believe it, until told differently. Sorry, I was so slow to "read between the lines".
RACE ON!!!