Cam choice for low comp 360?

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trebor75

trebor75

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I have been reading a lot, and doing a lot of searching on this forum. But I still am not able to fully grasp the science behind this So I thought it be best to ask. I followed 19 questions on Hughes website so I could provide you with the right info for helping me pick a cam.

Car - 1970 Plymouth Duster

Engine - 1973 LA 360 5.9 - Stock

Weight of vehicle, with driver - around 3110

What category does your use fit? - 99% street driven. I want a fun street car with lot's of torque

Altitude where vehicle will be run -
Latitude & Longitude for Stockholm, Sweden in decimal degrees: 59.4°, 18.1°.
Altitude/ elevation: 52 m (171 ft).

Present camshaft (duration @ .050", Lobe separation angle, lift etc...) - Don't know. Stock Valvetrain though.

Final gear ratio - I have 3.55 on now, I also have a 3.73 on the shelf

Stall speed of torque converter - 10" Turbo Action - advertised stall 3000

Tire height and width - 275/60-14

Fuel type - Pumpgas

Purpose of the Vehicle - 99% street driven. I want a fun street car with lot's of torque

Iron or aluminum heads - Stock Iron now. I'm gonna follow the "318 head porting for the average joe".

Compression Ratio - Have not measured, but advertised is 8.4:1. Stock pistons

Intake manifold - Dual Plane Edelbrock LD340

Header type and size - Cheap Longtube Hooker Headers

Carburetor size - Street Demon 650

Rocker arm type and ratio - Stock Hydralic / I also have a complete 273 Valvetrain with adjustable rockers and ball/cup pushrods

Will power adders be used? (N.O.S., turbo, supercharger etc...) - No

Cylinder head air flow numbers - Sorry I dont know


If possible I would like to use the stock rockers and pushrods. It would be nice if I did not have to do work on the heads, but milling is not out of the question. What I am after is a reliable street car with plenty of torque down low. The ones I have looked at is the XE262, XE268 and the Whiplash from Hughes. Sound if of no importance, I want a great respond and plenty of torque.

If you give advice, please include what I will need to get to be able to run your advice, springs etc. Thanks!
 
The problem building low end torque its hard to improve on factory.
As you add cams heads carbs etc... you expand the factories idle to 4500 powerband you can add 1000 rpm to idle to 5500. Above that you start moving the powerband to much of idle needing stall and gears to keep your car in the powerband. But if you want more than stock torque at about 1.1:1 lbs-ft to cid. The only way is the opposite of what's told to you. You need to gain more and more airflow to gain more torque it will be just higher up the rpm ladder. Mild builds can get you up 1.15:1 pretty hot engines is 1.2:1 and going above 1.3:1 for use average joes is a lot. Professional builders can over 1.4:1 I don't think there's to many over 1.5:1.

So it actually takes big cams heads carbs intakes headers to make torque.

But for your application with 3000 stall and 3.55 and especially 3.73 you can get more off idle somewhere between 1500-2500 and most built 360 are gonna peak between 5000 to 6000 rpm (350 hp to near 500 hp). Your compression is holding you back cause you go probably with xe275h but with the low cr with the 3.55 I'd go with xe262h and xe268h with 3.73.
 
If I was you I'd run the cam out of your 273 like was suggested before. Even if it's not 100% best choice for your engine. Your engine is a work in progress. Your talking about a little porting now and later buying heads and I imagine a full build down the line pick the right cam then.

Torque isn't something your gonna have to worry too much. This engine will make about 100 lbs-ft more than your 273 and probably the same hp wise. They can be but most 360 aren't that much of a revver anyways most make peak power between 4500 rpm to 5500 rpm (300 to 400 hp) with a 5000 rpm powerband. And with your stall and gears you'll be fine and if you don't mind gears go the 3.73 and all will be better :)
 
Problem I see is this: shooting for low end torque with a 3000 stall, 3.55's (maybe 3.73's that's sitting on the shelf), headers, and a 3100 lb car is putting a round peg in a square hole. I'd shoot for a duration between 224-230 @ 50 and lift between .470-484.
 
Alright, let me try to explain a little better. I know what I would like, and that is something different from my high winding 273 that needs the stall to get up and go of the line. I might have come off as wanting to use my Duster as a tow truck :) My 273 is fun on long straight roads, this 360 I want to be fast between red lights, and in my ignorance I thought that equals torque down low.

If the stall lis a problem I still have my stock converter on the shelf. I truly appreciate your taking the time to write and explaining. Sometimes it's just a bit over my head.
 
trebor75 said:
Alright, let me try to explain a little better. I know what I would like, and that is something different from my high winding 273 that needs the stall to get up and go of the line. I might have come off as wanting to use my Duster as a tow truck :) My 273 is fun on long straight roads, this 360 I want to be fast between red lights, and in my ignorance I thought that equals torque down low.

If the stall lis a problem I still have my stock converter on the shelf. I truly appreciate your taking the time to write and explaining. Sometimes it's just a bit over my head.
Click to expand...
Ok, this helped a lot. If you want a stop light warrior, keep the 3000 stall and gears. And I stick with my choice of cam lift and duration. Get some street legal drag radial tires for the back, because your going to need them. I had a 360 with a LD340 intake, 750 holley dp, 3.91's, 10 inch 3000 stall, a cam of 238 @ 50 with .484 lift, and I could blow the tires off at 25 mph.
Spinning ain't winning :D
 
273 said:
If I was you I'd run the cam out of your 273 like was suggested before. Even if it's not 100% best choice for your engine. Your engine is a work in progress. Your talking about a little porting now and later buying heads and I imagine a full build down the line pick the right cam then.

Torque isn't something your gonna have to worry too much. This engine will make about 100 lbs-ft more than your 273 and probably the same hp wise. They can be but most 360 aren't that much of a revver anyways most make peak power between 4500 rpm to 5500 rpm (300 to 400 hp) with a 5000 rpm powerband. And with your stall and gears you'll be fine and if you don't mind gears go the 3.73 and all will be better :)
Click to expand...

This is probably what I should do. I don't know why I get so carried away. I played around with CamQuest and the XE's just seemed to fit the bill.
 
318willrun said:
Ok, this helped a lot. If you want a stop light warrior, keep the 3000 stall and gears. And I stick with my choice of cam lift and duration. Get some street legal drag radial tires for the back, because your going to need them. I had a 360 with a LD340 intake, 750 holley dp, 3.91's, 10 inch 3000 stall, a cam of 238 @ 50 with .484 lift, and I could blow the tires off at 25 mph.
Spinning ain't winning :D
Click to expand...
This is exactly what I am after!
 
I know a a guy with a super similar motor combo he ran the lunati 268/276, Lift .494/.513 thats great for tq a 1,800-6,200. he had 727 with 3000 stall and 391 worked good and very responsive for leaving the line and such
 
Moparhead said:
the size smaller cam 475/.494 would be my choice honestly
Click to expand...
Are you referring to the Lunati Voodoo? On their site the don't get more specific than " Makes un-equaled power to 6200 RPM with proper valve springs." They don't recommend any springs. I have a set of Comp Cams Beehive Springs 26986-16. Would that work? Would the stock rockers and pushrods work too? Would it require machining of the heads?
 
trebor75 said:
Are you referring to the Lunati Voodoo? On their site the don't get more specific than " Makes un-equaled power to 6200 RPM with proper valve springs." They don't recommend any springs. I have a set of Comp Cams Beehive Springs 26986-16. Would that work? Would the stock rockers and pushrods work too? Would it require machining of the heads?
Click to expand...
i would call them for info my buddy ran the voodo valve springs off the sight just got the dual to be conservative i personaly if i go comp cam for example ex274h id go with the comp dual springs. crane on crane. id do the same with this cam keeps things consistent and my 340 has a near 500 lift cam and my motor has mp stock style rocekrs and push rods work great. i always like to port and gasket match
 
trebor75 said:
Are you referring to the Lunati Voodoo? On their site the don't get more specific than " Makes un-equaled power to 6200 RPM with proper valve springs." They don't recommend any springs. I have a set of Comp Cams Beehive Springs 26986-16. Would that work? Would the stock rockers and pushrods work too? Would it require machining of the heads?
Click to expand...

The cam he's referring to is the lunati 702. The springs they recommend with that cam is a dual spring and will require machining to the heads if I'm not mistaken.
 
Moparhead said:
i would call them for info my buddy ran the voodo valve springs off the sight just got the dual to be conservative i personaly if i go comp cam for example ex274h id go with the comp dual springs. crane on crane. id do the same with this cam keeps things consistent and my 340 has a near 500 lift cam and my motor has mp stock style rocekrs and push rods work great. i always like to port and gasket match
Click to expand...

I would call them too, If I wasn't living in Sweden :)
 
https://www.summitracing.com/parts/dcc-4452992/overview/
I used this cam twice in 318's. One with 318 heads, one with cut 360 heads. Used stock pushrods, rockers, and springs. Worked fine both times. I also put one in a 360 with 340 heads, and put one in a 340.
Not a bad idea to have the heads set for .500 lift, just to be sure. I only did once, all the other times no and maybe I was lucky. You'll loose some lift on the stock rocker assembly.
I did upgrade springs on a couple of the listed above, and I recommend it.
 
I ran the mp cam 318willrun suggested. It was a 340 9.5 comp. rpm intake, 750 holley,2.02 j heads, 2200 converter, and 3.55s. Best time was 13.15 at 104 with 26 in. drag radials. Its a good cam.
 
If you decide on the mp cam. Shop around for the lowest price. Mp cams just took a huge jump in prices. Some cam and lifters are now 400.00 plus dollars. Some retailers still have some at the old prices. Thanks mopar.
 
Whiplash. That's what they're designed for.
 
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