Are you all seeing an influx of over cammed combinations?

General engine tech -- Drag Racing to Circle Track

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prairiehotrodder
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Re: Are you all seeing an influx of over cammed combinations?

Post by prairiehotrodder » Thu Oct 26, 2017 11:25 pm

i grew up reading hot rod and car craft magazines. They all preached mild cams, dual plane intakes, small tube headers, lower compression and vacuum secondary carbs. I followed their example and built lots of engines that didn't have much power. Now i'm finally getting to the place where i like the aggressive cams and wilder parts. Its more fun. When i want to go slow i drive my 98 Ford Escort wagon.

In building big cube motors i've found that a cam that seems "to big" actually works pretty good.
Brian
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kimosabi
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Re: Are you all seeing an influx of over cammed combinations?

Post by kimosabi » Fri Oct 27, 2017 1:10 am

Hell I can make a stock cam sound lumpy no problem. Retard the timing and put a huge intake and exhaust on.

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Re: Are you all seeing an influx of over cammed combinations?

Post by cjperformance » Fri Oct 27, 2017 1:29 am

kimosabi wrote:
Fri Oct 27, 2017 1:10 am
Hell I can make a stock cam sound lumpy no problem. Retard the timing and put a huge intake and exhaust on.
Na just pull the choke on!
Craig.

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Re: Are you all seeing an influx of over cammed combinations?

Post by joe 90 » Fri Oct 27, 2017 2:40 am

No, you lean it out at idle.

I can do that from the drivers seat just by twiddling a knob on the computer.

Makes a normal cam sound like a hot one.


On the other hand ......with a hot cam, I can make it idle like a normal one.


It's all about how it's tuned.

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Re: Are you all seeing an influx of over cammed combinations?

Post by Fireonthemountain » Fri Oct 27, 2017 2:52 am

Pull a spark plug wire or 2 LOL

Big cams in large engines work better when they have bad air flow. Put big flowing heads and intake on it and watch it suddenly slow down, because it is over cammed and now shows its teeth.

I would rather, at my advanced age, be fast rather than look or sound fast. I have ridden in and had brutal cars, without big cams nor double pumpers on the street. Anymore I could care less about hearing my exhaust or feel its shift putting around. But do what you will with your car is the hotrod way.

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Re: Are you all seeing an influx of over cammed combinations?

Post by kimosabi » Fri Oct 27, 2017 3:02 am

joe 90 wrote:
Fri Oct 27, 2017 2:40 am
No, you lean it out at idle.

I can do that from the drivers seat just by twiddling a knob on the computer.

Makes a normal cam sound like a hot one.


On the other hand ......with a hot cam, I can make it idle like a normal one.


It's all about how it's tuned.
I'm pretty lean at idle now and yes it sounds like shit when cold but fully warm it's surprisingly smooth. A normal cam would be even smoother warmed up, and lazy. No, retard the timing and make those cast iron manifolds glow I say!

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Re: Are you all seeing an influx of over cammed combinations?

Post by Mark O'Neal » Fri Oct 27, 2017 4:56 am

There is a distinct reason why I chose to run the 3/4 race cam instead of the 1/2 race.

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Re: Are you all seeing an influx of over cammed combinations?

Post by Rick Finsta » Fri Oct 27, 2017 7:35 am

Mark O'Neal wrote:
Fri Oct 27, 2017 4:56 am
There is a distinct reason why I chose to run the 3/4 race cam instead of the 1/2 race.
Being asked if you have a 1/2 or 3/4 cam in your car is like being asked to play Freebird when you're on stage. You think it is just an industry joke until it happens to you.

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Re: Are you all seeing an influx of over cammed combinations?

Post by cab0154 » Fri Oct 27, 2017 8:05 am

I was wondering if my cam was too big for my combo, one of the cam guys ran the combo through his software and it turned out my choices from the comp lobe book are 2* shorter and .030 lower on lift than his program says it will want. Duane Busch once said something to the effect of the heads don't flow if the valves aren't open.

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Re: Are you all seeing an influx of over cammed combinations?

Post by joe 90 » Fri Oct 27, 2017 8:15 am

A 3/4 race cam by tradition is about 280 deg..........been there , done that.

At the same time a half race cam might be 260 deg.......been there done that too in another engine.

A "real " cam is well over 300 deg.
it starts of at about 260 and changes over to 315 deg or so at what ever RPM you want it to........today. With electronics.
Because we can.
Not 40 years ago.






But it's not a lot different from reading in magazines where their whole purpose is to make sales for their advertisers.
Stop reading magazines.

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Re: Are you all seeing an influx of over cammed combinations?

Post by kimosabi » Fri Oct 27, 2017 9:36 am

Be it VVTi, Vanos, Vtec etc all they do is change the cam timing. Duration is the same. Lobes don't change.

Hope and change!

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Re: Are you all seeing an influx of over cammed combinations?

Post by Newold1 » Fri Oct 27, 2017 10:13 am

There are basically two types of performance and racing engine users:

Those enthusiasts who want an engine that sounds "bad & cool" and select camshafts that enhance that sound

and there are those racing individuals with engines that they don't care at all how there engine sounds, but are just concerned with how it runs and WINS!

Their camshafts are designed and selected by how well they make their engine perform with maximum power!

Join one club or the other and HAVE FUN! :wink:

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Re: Are you all seeing an influx of over cammed combinations?

Post by stangbuilder » Fri Oct 27, 2017 1:15 pm

Funny reading this, I am 62 years old been down that road to many times.I now drive a 67 mustang with a 477 in fe that came off dyno at just south of 700 hp..It idles at 700 rpm with efi..and it smooth....I can pull 5th gear at 1200 rpm and drive away with no issues smooth..By the way the cam one of jones grinds 238 242 at 50. Its a soild flat tappet deal...Pulls like a frieght train to about 6800 to 7000 rpm. Car only weights 3100 without me. And.I shit you not.The car is a hand full to drive running it through the gears on street tires

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Re: Are you all seeing an influx of over cammed combinations?

Post by bigpoppapreston » Fri Oct 27, 2017 1:24 pm

stangbuilder wrote:
Fri Oct 27, 2017 1:15 pm
Funny reading this, I am 62 years old been down that road to many times.I now drive a 67 mustang with a 477 in fe that came off dyno at just south of 700 hp..It idles at 700 rpm with efi..and it smooth....I can pull 5th gear at 1200 rpm and drive away with no issues smooth..By the way the cam one of jones grinds 238 242 at 50. Its a soild flat tappet deal...Pulls like a frieght train to about 6800 to 7000 rpm. Car only weights 3100 without me. And.I shit you not.The car is a hand full to drive running it through the gears on street tires
LOVE IT!!!
-Poppy

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Re: Are you all seeing an influx of over cammed combinations?

Post by Krooser » Fri Oct 27, 2017 1:54 pm

bigpoppapreston wrote:
Fri Oct 27, 2017 1:24 pm
stangbuilder wrote:
Fri Oct 27, 2017 1:15 pm
Funny reading this, I am 62 years old been down that road to many times.I now drive a 67 mustang with a 477 in fe that came off dyno at just south of 700 hp..It idles at 700 rpm with efi..and it smooth....I can pull 5th gear at 1200 rpm and drive away with no issues smooth..By the way the cam one of jones grinds 238 242 at 50. Its a soild flat tappet deal...Pulls like a frieght train to about 6800 to 7000 rpm. Car only weights 3100 without me. And.I shit you not.The car is a hand full to drive running it through the gears on street tires
LOVE IT!!!
After seeing that an old Duntov 30/30 cam is too big for a .030 over 283 with a two barrel and stock manifolds in a '61 Impala ragtop daily driver I've S-L-O-W-L-Y learned that bigger isn't always better... took 50+ years!

My kid's dirt b-mod shocked the cr*p outa him, me and the cars PO after the kid's nicely 'built on a budget' 355 showed incredible acceleration of the corners using one of Mike Jone's relatively mild grinds... the guy who previously owned the car looked at the cam specs and declared it was suitable for a street stock but was way too mild for a modified. Made a believer out of him. The 'freight train' analogy is spot on IMHO.

Now Mike is going to grind another flat tappet cam for my low buck dirt late model 383... again the specs seem pretty tame but I trust his advice. Most guys are running 10 degrees more duration and another .25 more lift with heads that don't flow what mine do.

My good friends SBC WISSOTA spec, Brodix headed 358 SBC is another one with a way bigger cam than some would suggest. And it's an old I*ky grind that is likely 30 year old technology. He now sez he needs even more to keep up... I'll see if he listens to reason.
Last place in the B-main is better than anyplace in the grandstands...

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