Author
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Topic: Bigger Cam?
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jsracingbbf Gearhead Posts: 2160 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 02-28-2003 11:43 PM
Several racers I know have suggested my CAM is too small for my application. Truthfully when I bought the cam the car had stock heads and the car itself was heavier. It is a solid roller. Here are the cam specs: Intake Dur = 265 @ .050 Exhaust Dur. = 275 @ .050 Intake & exhaust lift = 709 Lobe seperation = 110 Lash is .030Its one of John's special grinds (Bullet) Rockers are Comp rollers 1.76 CR= 12.5:1 CID = 514 Aluminum SCJ heads ( old style ) ported Wieand tunnel ram ported to match the heads enderle alky injected hat 2 18th " primaries : 4" collectors 2 speed power glitch 1.76 low gear; 4.56 rear gears 32 X 14 GY's Car weighs 2800 lbs with me in it. ( big ole boy ) I have had it suggested to me to buy a cam with at least 750 lift. What do the CAM gurus here think? No fighting please BTW this motor was built for approx. $7000.00 including the injection.
------------------ Jerry 69 Mustang Pro ET Drag 70 Mustang retired former footbrake car "This is FORD Country! On a Quiet night you can hear a Chevy Rust"
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cracing Gearhead Posts: 159 From: Saltillo Miss. USA Registered: Jan 2002
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posted 03-01-2003 12:52 AM
Sounds pretty close for our 1/2 race tracks there big ole boy! Should pull real good with that gear & 1.76. Dont need much cam for the RPM range you/we will be in. Got Torque? Oh yes!
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jsracingbbf Gearhead Posts: 2160 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 03-01-2003 11:43 AM
must be the cam Gurus week off JS
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jsracingbbf Gearhead Posts: 2160 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 03-02-2003 02:26 PM
Second thought, it MUST be the perfect grind, silence gives CONSENT. I'm kind of lacking in the cam and convertor dept on knowledge, thanks for all the help JS PS: Thanks Bob at least you replied, I figured even Clam head would say something smart alleck. (shrugs)
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steve'66 Gearhead Posts: 7226 From: Sonoma,CA,USA Registered: Mar 2000
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posted 03-02-2003 11:02 PM
Jerry,I'm no cam "expert" but I like the cam you're running. Too many folks run too big a cam. It's matched to your convertor right? Run it and enjoy. SteveW
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jsracingbbf Gearhead Posts: 2160 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 03-03-2003 12:35 AM
Thanks Steve, I am certainly not a cam expert. Bob sent me some good advice on setting my lash, so I'm good to go. I don't know what I was thinking anyway, I'm very close to cranking up. Can't second guess cam choices now. ------------------ Jerry 69 Mustang Pro ET Drag 70 Mustang retired former footbrake car "This is FORD Country! On a Quiet night you can hear a Chevy Rust"
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Moneymaker Administrator Posts: 21725 From: Lyons, IL, USA Registered: May 99
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posted 03-03-2003 12:40 AM
When you exceed .750 lift valve spring life becomes a serious issue and consideration. A larger cam may and probably will make more power, but at the cost of some consistancy in the heat and half the current valve spring life you now enjoy.------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00,'01,'02,&'03 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!" www.moneymakerracing.com
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jsracingbbf Gearhead Posts: 2160 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 03-03-2003 12:51 AM
Good Info thanks Alex JS
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Moneymaker Administrator Posts: 21725 From: Lyons, IL, USA Registered: May 99
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posted 03-03-2003 12:53 AM
One way to see if it wants a bigger cam is to tighten up the lash .008 to .010. If it picks up it wants a bigger cam.------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00,'01,'02,&'03 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!" www.moneymakerracing.com
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'69Stang Gearhead Posts: 205 From: Detroit, MI USA Registered: Jan 2002
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posted 03-03-2003 09:16 AM
Alex: How much can the lash be safely tightened up on a solid/solid roller? For example if the cam card calls for .020 is it o.k. to go to .010, or .005? And does the shortening of the lash effect the duration of the cam besides the lift? It seems as if it would...... [This message has been edited by '69Stang (edited 03-03-2003).]
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'69Stang Gearhead Posts: 205 From: Detroit, MI USA Registered: Jan 2002
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posted 03-03-2003 11:23 AM
TTT
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Moneymaker Administrator Posts: 21725 From: Lyons, IL, USA Registered: May 99
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posted 03-03-2003 12:00 PM
quote: Originally posted by '69Stang: Alex: How much can the lash be safely tightened up on a solid/solid roller? For example if the cam card calls for .020 is it o.k. to go to .010, or .005? And does the shortening of the lash effect the duration of the cam besides the lift? It seems as if it would...... [This message has been edited by '69Stang (edited 03-03-2003).]
Safely? I guess that's a difficult question to answer. I guess to be dead safe then variances of .015 either way would have to be the limit. I have personally opened up the lash on certain solid roller cams as much as .025 and seen improvements. This was for testing purposes. I regularly loosen the lash on MM and some other SS racer friends engines .010 to .015 for one or two blasts. This is for situations where we are needing to pick up a tenth or more. It's hard on the valve train as the lifters litterally get launched off the cam. With "good" parts, there hasn't been a problem of any kind. Some of the racers we have helped like the performance enhancment so much that they have left them at .040 or .045. After 50-60 runs all is still well. Most of these racers are bracket racers who can't afford to change roller cams at the drop of a hat and were misguided on their initial cam selection. So to answer your question, I'd say you are pretty much dead safe at .015 either way with good parts.
------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00,'01,'02,&'03 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!" www.moneymakerracing.com
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'69Stang Gearhead Posts: 205 From: Detroit, MI USA Registered: Jan 2002
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posted 03-03-2003 03:18 PM
Thanks Alex, I think I will tighten mine up .010 and see how it likes it.
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