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#2401254 - 11/09/17 11:52 PM Small block single pattern hydraulic flat tappet cams
mgoblue9798 Offline
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Registered: 03/16/10
Posts: 120
Loc: Atlanta, GA
Are there any modern off the shelf options?
I got a deal on a lightly used blueprint engines 408LA stroker that has a magnum head conversion. Current cam is the old style .238@.050 .474 purple shaft. All I am finding is dual pattern cams which I don't need with magnum heads and headers.

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#2401335 - 11/10/17 09:05 AM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
gregsdart Offline
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Registered: 01/21/03
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Loc: Frostbitefalls (Rocky&Bullwink...
You may not need it, but dual pattern cams can have a serious power advantage, and from what little I know, are very effective. I put together a 408 with Magnum EQ heads, dual plane intake, 10/1 compression. Cam is a Comp Muthr Thumpr with 235/249/ 107 LSA duration. It made 500 hp from 5200 to 6100 rpm,519 TQ at 4100. You can and probably should have a custom grind made just for you.
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#2401406 - 11/10/17 12:00 PM Re: Small block single pattern hydraulic flat tappet cams [Re: gregsdart]
mgoblue9798 Offline
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Registered: 03/16/10
Posts: 120
Loc: Atlanta, GA
Educate me. I thought the only purpose for a dual pattern was to help out the exhaust side when needed. Magnum style heads did not need the help I have read. Is there more to it than that? Thanks.

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#2401416 - 11/10/17 12:22 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
madscientist Offline


Registered: 09/17/14
Posts: 1649
Loc: Washington
Originally Posted By mgoblue9798
Educate me. I thought the only purpose for a dual pattern was to help out the exhaust side when needed. Magnum style heads did not need the help I have read. Is there more to it than that? Thanks.


Call Jim at Racer Brown and have him grind you something.

The dual pattern cam is highly overrated.
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Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston

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#2401418 - 11/10/17 12:23 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
madscientist Offline


Registered: 09/17/14
Posts: 1649
Loc: Washington
As a second thought...the intake port is so small and weak for most engines you should be running a dual pattern cam.

It should have 10 MORE degrees on the intake. Not more on the exhaust.

Also, is a dual pattern cam less intake duration or more exhaust duration?
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Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston

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#2401544 - 11/10/17 04:58 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
Michael Ecks Offline
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Registered: 01/20/03
Posts: 1023
Loc: Columbus, GA
Howards cams has a number of single pattern cams and I think the lunati street master line is all single pattern. Don't just look in the summit catalog. On thier website I think single versus dual pattern is something you can filter in a search.

Also go to the sites for lunati, comp, etc.. and download their catalogs to look.

FWIW I don't recall magnum heads prefering single pattern, I thought the 308 LA head was the only one that ran better with single pattern.
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#2401599 - 11/10/17 06:52 PM Re: Small block single pattern hydraulic flat tappet cams [Re: gregsdart]
Crizila Offline
master

Registered: 10/31/03
Posts: 7482
Loc: Az
Originally Posted By gregsdart
You may not need it, but dual pattern cams can have a serious power advantage, and from what little I know, are very effective. I put together a 408 with Magnum EQ heads, dual plane intake, 10/1 compression. Cam is a Comp Muthr Thumpr with 235/249/ 107 LSA duration. It made 500 hp from 5200 to 6100 rpm,519 TQ at 4100. You can and probably should have a custom grind made just for you.
iagree and if you are looking for off the shelf, Hughes Engines has a wide variety to choose from. They are the small block Chrysler guru's IMO.
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#2401898 - 11/11/17 11:04 AM Re: Small block single pattern hydraulic flat tappet cams [Re: Crizila]
mgoblue9798 Offline
member

Registered: 03/16/10
Posts: 120
Loc: Atlanta, GA
Bought numerous things from Hughes, but looked at their website and it was all dual pattern. Maybe I will give them a call and ask why? Thanks for your help sir.

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#2401902 - 11/11/17 11:07 AM Re: Small block single pattern hydraulic flat tappet cams [Re: madscientist]
mgoblue9798 Offline
member

Registered: 03/16/10
Posts: 120
Loc: Atlanta, GA
Originally Posted By madscientist
As a second thought...the intake port is so small and weak for most engines you should be running a dual pattern cam.

It should have 10 MORE degrees on the intake. Not more on the exhaust.

Also, is a dual pattern cam less intake duration or more exhaust duration?


I should have said magnum style head conversion. It will actually have a set of the Indy RHS heads that have been prepped. Dual pattern can be either way, but the off the shelf stuff I have seen has increased duration/lift on the exhaust lobe for the small block.
Thank for you help.

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#2401903 - 11/11/17 11:07 AM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
Cab_Burge Offline
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Registered: 08/23/03
Posts: 29539
Loc: Bend,OR USA
Take a look at the lobes at Comp Cams, especially the XL-HL series scope
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#2401904 - 11/11/17 11:12 AM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
crabman173 Offline
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Registered: 01/01/06
Posts: 3549
Loc: Big Lick , North Carolina
Fun part of all this is
You can take 15 cams that are in same family size wise from every maker--dyno back to back and you will be surprised how little diff there is--YES one will make 20 more HP on a 500 HP build but almost every 408 back yard built by anybody with any hyd cam --guys doing one engine not engine pros--will be between 475 and 500 HP so ....it is not a life and death deal--you select a cam that is not too big to live with and drive the way you intend to drive and go with it simple as that--who cares and who will know that it is 475 or 495--big deal
Single pattern cams work Great --dual patterns are way over rated
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#2401906 - 11/11/17 11:15 AM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
B3422W5 Offline
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Registered: 01/20/03
Posts: 9914
Loc: Portage,michigan
Am probably looking for a cam for my new 418, and Dwayne liked a single pattern for it over a dual pattern i was considering.
Should have said its a solid flat tappet


Edited by B3422W5 (11/11/17 11:16 AM)
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#2402036 - 11/11/17 03:35 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
crabman173 Offline
master

Registered: 01/01/06
Posts: 3549
Loc: Big Lick , North Carolina
I have found that the 238 ish range in a 408 makes a great street car and driver at 475 Hp range( with zero effort-no porting etc) and to make 500 plus they seem to like a lot bigger cam that is not as good on the street / vacuum etc
Love that idea of a solid!! They make some steam and are so much cheaper than a roller
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#2402129 - 11/11/17 05:52 PM Re: Small block single pattern hydraulic flat tappet cams [Re: crabman173]
BradH Online   content
I Live Here

Registered: 01/30/03
Posts: 13327
Loc: Valhalla... eventually
Originally Posted By crabman173
Single pattern cams work Great --dual patterns are way over rated

Nothing is a for-sure thing with cam design, and it's always a case of "it depends." The only sure thing is the answer doesn't come from a catalog or a web site.

I'm still amused by a magazine article from years ago that was supposed to show the merits of a well-known cam company's new series of dual-pattern grinds. The test compared it to one of their older single-pattern designs. The old cam, IIRC, made more torque, made almost as much HP, and was more stable at higher RPM. I don't recall how the article tried to spin the results, but it didn't do that new cam series any favors IMO.

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#2402153 - 11/11/17 06:22 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
fast68plymouth Offline
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Registered: 01/20/03
Posts: 10323
Loc: So. Burlington, Vt.
I still use a lot of single pattern cams....... And some of the builds I've been happiest with had one in it.
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#2402162 - 11/11/17 06:46 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
polyspheric Offline
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Registered: 10/10/07
Posts: 2253
Loc: New York
the only purpose for a dual pattern was to help out whichever side needs it.
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#2402332 - 11/11/17 11:11 PM Re: Small block single pattern hydraulic flat tappet cams [Re: polyspheric]
Crizila Offline
master

Registered: 10/31/03
Posts: 7482
Loc: Az
Originally Posted By polyspheric
the only purpose for a dual pattern was to help out whichever side needs it.
up and one side or the other almost always needs it.
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#2402352 - 11/11/17 11:44 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
Exit1965 Offline
master

Registered: 07/31/03
Posts: 3194
Loc: Rancho Cordova, CA
In my low comp 440 I ran an Isky mega cam 292, which is 244 @ .050 and 108 lsa, .505 lift. It sounded good and ran/pulled great.

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#2402356 - 11/11/17 11:49 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
polyspheric Offline
top fuel

Registered: 10/10/07
Posts: 2253
Loc: New York
Sometimes the bias can be tweaked toward the intake side with higher ratio rockers (but this generally doesn't work on the exhaust side, which is more heavily dependent on the XO opening point than lift).

As I have posted before, the only reason why manufacturers use the same lobe and rocker on both valves is: it's the cheapest way. They try to get the ports to work that way even if it's not particularly efficient.
The function of the two ports (gas speed, temperature, pressure) is as different as chalk and cheese, and their needs for an event are very different.

The say on whether dual pattern will help should be your porter as the final analyst of the relative port capacities.
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#2402791 - 11/12/17 08:29 PM Re: Small block single pattern hydraulic flat tappet cams [Re: mgoblue9798]
Medlock51 Offline
member

Registered: 06/15/16
Posts: 96
Loc: Wisconsin
Make sure the cam you choose is a Mopar cam designed to us a .904 lifter... most of those shelf cams are Chevy grinds.

www.jonescams.com .Mike Jones
www.camcraftcams.com ... Charles

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