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Cam/Converter ideas for a 493: Idle to 5800 rpm range
#1635832
06/19/14 11:38 PM
06/19/14 11:38 PM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
Striving for excellence
Joined: Feb 2010
Posts: 18,493
Granite Bay CA
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I may never drag race my Charger. I certainly will never do it for competition or money. The Lunati 316/326 solid makes great power but the operating range makes it a less than ideal cam for the way I want to use the car.
My interests are sorta like the how the new Challengers are marketed: A big car that rides decent, handles and stops great and is a decent quarter-miler. I want to feel the quick throttle response at midrange RPMs where the engine usually operates. Peak power at 6000 rpms may be the way to lower ETs but that leaves me a bit soft at 2200-2800 when I'm driving through twisty mountain roads.
Last Summer I'd had enough of the detonation problems and I wanted to stop it. At the time I was not willing to pull the engine to swap in dished pistons so I took the advice that many gave and installed a cam with lots more lift and duration. This trick did not help since the new cam turned out to have an earlier intake closing than the MP '509 I had in there before. In the late fall I had the heads ported and installed .075 Cometic head gaskets to lower the CR to 10.07 to one. Currently the car runs strong at WOT and does not detonate at all. It may be hard for some to understand my desire to dig back in, but what I really want is an engine that has tight, immediate throttle response from Idle to 5500 or so. I have a 727 with a Gear Vendors Overdrive. At freeway speeds, the car just feels lazy. At any rpm under 3000 it feels like the converter is just too loose. I feel that with almost 500 inches of engine, I should be able to boil the tires right off an idle. I have the distributor curved right. The Demon 850 is a little fat but the plugs stay clean. The engine runs cool. I think the engine and trans are more suited for 1/4 mile WOT runs as compared to what I want.
Not that I am anxious, but I am open to the idea of pulling the engine to either install dished pistons or have my Ross pistons milled. Last Summer when we spoke, Dwayne Porter suggested that I have the NON quench side milled .040 then run a Cometic .027 gasket. He figured I'd gain quench while reducing the CR. As with any matched combo, the cam, compression and converter need to play well together. I'm willing to get a new converter as well.
Going to a smaller cam will raise the cylinder pressure which is why I feel that I'd need to juggle the CR and get the quench back. A stock rated torque converter may be right in line for my needs too but I'm willing to consider any advice on that.
Thanks all, Greg
Last edited by Frankenduster; 07/11/14 06:45 PM.
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: ademon]
#1635834
06/20/14 12:08 AM
06/20/14 12:08 AM
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Joined: Jan 2007
Posts: 7,664
IN
ahy
master
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master
Joined: Jan 2007
Posts: 7,664
IN
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I run a 496, 10.2 CR, ~.040" quench, EFI, Ed head with a MM lobe mechanical flat tappet with 243@.050 duration. Torque and drivability in the 2000+ range are very good and it really rips in the 3000-5000 RPM mid range. The cam was speced by Mike at Muscle Motors for my engine combo. It will even pull clean from 1200 RPM as long as I don't completely stomp it. I think the tight quench and moderate CR help the combo a lot. It runs fine on 92/93 pump gas. Even though the lobe profile is considered a bit aggressive for "mixed" driving, I have 14k miles on it w/o problem.
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: Kern Dog]
#1635838
06/20/14 04:22 AM
06/20/14 04:22 AM
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Joined: Jan 2007
Posts: 2,431
SK,Canada
gregsrt
top fuel
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top fuel
Joined: Jan 2007
Posts: 2,431
SK,Canada
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This is the cam that Mike @ Muscle Motors spec'd for my 512 lo deck. It has about 10.5:1 comp, idles at 700rpm, I can cruise at 1100rpm with no issues. Power to 6000ish. My convertor was custom made as per my engine and cam specs by Patrick @ SMR. It's an 11" that cruises like stock and flashes about 3500 when hammered from a standstill.....tires spin instantly.
An association of men who will not quarrel with one another is a thing which has never yet existed, from the greatest confederacy of nations down to a town meeting or a vestry.
Thomas Jefferson
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: gregsrt]
#1635839
06/20/14 05:16 AM
06/20/14 05:16 AM
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Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar
master
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Quote:
This is the cam that Mike @ Muscle Motors spec'd for my 512 lo deck. It has about 10.5:1 comp, idles at 700rpm, I can cruise at 1100rpm with no issues. Power to 6000ish. My convertor was custom made as per my engine and cam specs by Patrick @ SMR. It's an 11" that cruises like stock and flashes about 3500 when hammered from a standstill.....tires spin instantly.
Thats just a bit larger than the Comp XR286HR-10 cam that I'm running in my 10.3:1 compression 505 stroker. It is 236/242@ 0.050, 0.580"/0.577" with 1.6:1 rocker arms. This seems to be pretty mild for this sized engine, but it has great torque. With the 5-speed manual, I drive around at 1,200 to 1,500 RPM most of the time, but it seems to pull to 6000 RPM easy. 6,000 is where the rev limiter is set and I have hit the limiter several times. I think this engine could even go with a slightly larger cam?
I need to get the car on a chassis dyno to see what the torque curve looks like, and to tune the EFI.
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: Kern Dog]
#1635841
06/20/14 12:48 PM
06/20/14 12:48 PM
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Joined: Mar 2007
Posts: 3,285
West Coast, USA
jbc426
master
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master
Joined: Mar 2007
Posts: 3,285
West Coast, USA
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Quote:
Thanks again guys. Part of me wonders if most of the lazy feel is due to the torque converter. I've driven cars and trucks that feel really snappy immediately from idle speed. One main concern though is the risk of going to a converter that is too tight. I can idle the engine down to 800 rpms or less in neutral but that results in too low when in drive.
Am I right that an engine with more torque tends to increase the stall speed? By this I mean, (Just for grins) would a stock 12" converter stall higher with my engine than it would in a mild 360? The reason I ask is because I have 3 or 4 727 converters in my stash. One is an 11" unit. For very little money I could try a different converter to see what effect it has.
Call Precision Torque Converters of New Hampton and order a nice $400+ something dollar custom converter, and put a hydraulic roller in spec'd by Dwayne Porter or Hughes Engines and enjoy your car.
Modern torque converters are so much more efficient at cruise than they were 15 years ago, its amazing, plus they wake up your car. It's a critical component, just like the right cam. When the two are matched to your ride, nirvana ensues!
PS I still have a small scab on my hand! The Outlaw Dennis H and crew are on the way up today leaving around noon. Wish I was going, but I have to stuff a Passon 5-speed in my e-body. 
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: gregsrt]
#1635843
06/20/14 03:00 PM
06/20/14 03:00 PM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
Striving for excellence
Joined: Feb 2010
Posts: 18,493
Granite Bay CA
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Quote:
This is the cam that Mike @ Muscle Motors spec'd for my 512 lo deck. It has about 10.5:1 comp, idles at 700rpm, I can cruise at 1100rpm with no issues. Power to 6000ish. My convertor was custom made as per my engine and cam specs by Patrick @ SMR. It's an 11" that cruises like stock and flashes about 3500 when hammered from a standstill.....tires spin instantly.
I called pat at SMR and he felt that they couldn't build a proper converter for my car. Pat emailed with a response of something to the effect of: The camshaft operating range is too high for the type of driving that you intend to do. I'm afraid that a converter with a lower stall may result in unsatisfactory performance.
The cam is listed as a 383-440 cam with an operating range of 4700-7200. This seems odd though because the engine does come alive much earlier than that. Why don't these cam suppliers ever extend the application range to include longer stroke engines? Many people have these 451, 471, 493 and larger engines yet I've never seen these engine sizes listed when looking at cams. It must be like many here have said: I need to call a pro and have a cam custom selected.
GregsR/T: The behavior of your car seems like it is exactly what I want. This gives me plenty to think about. Thanks everyone, Greg
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: Kern Dog]
#1635844
06/20/14 08:24 PM
06/20/14 08:24 PM
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Joined: Mar 2007
Posts: 3,285
West Coast, USA
jbc426
master
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master
Joined: Mar 2007
Posts: 3,285
West Coast, USA
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Quote:
Quote:
This is the cam that Mike @ Muscle Motors spec'd for my 512 lo deck. It has about 10.5:1 comp, idles at 700rpm, I can cruise at 1100rpm with no issues. Power to 6000ish. My convertor was custom made as per my engine and cam specs by Patrick @ SMR. It's an 11" that cruises like stock and flashes about 3500 when hammered from a standstill.....tires spin instantly.
I called pat at SMR and he felt that they couldn't build a proper converter for my car. Pat emailed with a response of something to the effect of: The camshaft operating range is too high for the type of driving that you intend to do. I'm afraid that a converter with a lower stall may result in unsatisfactory performance.
The cam is listed as a 383-440 cam with an operating range of 4700-7200. This seems odd though because the engine does come alive much earlier than that. Why don't these cam suppliers ever extend the application range to include longer stroke engines? Many people have these 451, 471, 493 and larger engines yet I've never seen these engine sizes listed when looking at cams. It must be like many here have said: I need to call a pro and have a cam custom selected.
GregsR/T: The behavior of your car seems like it is exactly what I want. This gives me plenty to think about. Thanks everyone, Greg
It's all about the combination. You're on the right track by matching the cam with a right converter. The rest of your motor and car for that matter is beautiful!
I'm running this cam in my 493" motor with ported Indy EX's and 12.8 to 1 static compression.
http://www.hughesengines.com/Index/produ...mp;partid=23988
It's all over before 6000 rpm, but look at the cam card on this link. The stroker motor makes it act like a much smaller cam. I have the T&D 1.6's on it.
The motor wants a wider love centerline and lots more duration and lift, but then I will loose my low end drivability. It still doesn't really like to be in any gear higher that 1st below 1800 rpm. It starts to lope too much.
That's why I switched my gears in my Dana 60 from 3.54's to 3.73's. That way while I'm cruising at 65 to 70 in 5th (Passon)the motor will be happier. It likes to cruise at 2200 rpm, which should be just about 73 mph with the 3.73's.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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Re: Cam ideas for a 493: Idle to 5800 rpm range
[Re: Kern Dog]
#1635847
06/22/14 01:09 AM
06/22/14 01:09 AM
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Joined: Feb 2005
Posts: 4,318
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,318
Prospect, PA
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Quote:
I may never drag race my Charger. I certainly will never do it for competition or money. The Lunati 316/326 solid makes great power but the operating range makes it a less than ideal cam for the way I want to use the car.
My interests are sorta like the how the new Challengers are marketed: A big car that rides decent, handles and stops great and is a decent quarter-miler. I want to feel the quick throttle response at midrange RPMs where the engine usually operates. Peak power at 6000 rpms may be the way to lower ETs but that leaves me a bit soft at 2200-2800 when I'm driving through twisty mountain roads.
Last Summer I'd had enough of the detonation problems and I wanted to stop it. At the time I was not willing to pull the engine to swap in dished pistons so I took the advice that many gave and installed a cam with lots more lift and duration. This trick did not help since the new cam turned out to have an earlier intake closing than the MP '509 I had in there before. In the late fall I had the heads ported and installed .075 Cometic head gaskets to lower the CR to 10.07 to one. Currently the car runs strong at WOT and does not detonate at all. It may be hard for some to understand my desire to dig back in, but what I really want is an engine that has tight, immediate throttle response from Idle to 5500 or so. I have a 727 with a Gear Vendors Overdrive. At freeway speeds, the car just feels lazy. At any rpm under 3000 it feels like the converter is just too loose. I feel that with almost 500 inches of engine, I should be able to boil the tires right off an idle. I have the distributor curved right. The Demon 850 is a little fat but the plugs stay clean. The engine runs cool. I think the engine and trans are more suited for 1/4 mile WOT runs as compared to what I want.
Not that I am anxious, but I am open to the idea of pulling the engine to either install dished pistons or have my Ross pistons milled. Last Summer when we spoke, Dwayne Porter suggested that I have the NON quench side milled .040 then run a Cometic .027 gasket. He figured I'd gain quench while reducing the CR. As with any matched combo, the cam, compression and converter need to play well together. I'm willing to get a new converter as well.
Going to a smaller cam will raise the cylinder pressure which is why I feel that I'd need to juggle the CR and get the quench back. A stock rated torque converter may be right in line for my needs too but I'm willing to consider any advice on that.
Thanks all, Greg
I suggested several times a year ago to have the chambers opened to 90 ccs. Best low cost option to reducing CR and keeping quench. You pulled the heads and did everything but this, and you could have had it done for next to nothing at the time. Now you're contemplating a piston redo. You are truly your own worst enemy.
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I did have the Mopar 2.77 1st gear in the 727 and from 3.73 to 4.30 ratio gears in the rear end, it ended up with 4.10 and a set of M/T 315x6015 ET Street Radials for the street, I could make them rascals turn(break loose) on demand in all gears on the street 
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