got a 73 valiant with 318 was hard to start then started missing turned out i lost a cam lobe. i want to replace the cam with something that will lope but still work with my stock 2bl carb until i can get a 4bbl setup. summit has a cam with a duration of 262/272 and lift of 420/442 i think the centerline was 110. ive been told by different people this will change my idle and some say it wont. any help would be greatly appreciated hoping to order something this week. i drive a truck and have till friday to get the order in. thanks
cam shaft selection
- Thread starter rigrunner
- Start date
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340 8BBL
Well-Known Member
i had isky super cam in my 73 valiant with a 318.they offer 2 grinds:the 256 and 262.i had the 256,but they ground it with a tight lsa.it had a slight lope at idle,good mpg,and decent power.ive had no problems with any isky produts,however they are pricy and there are downsides to a narrow lsa.i was happy with the cam they made me,but there are probably better choices out there.and yes i think the summit cam will change your idle a little.
intimidator
Mopar or No Car
A few years back we took a 318 and put it in a 70 dart. We used a stock grind cam from a 1970 Dodge 340 motor. This cam gave it some lope plus it gave it a lot of performance. We had a Holley 500 2 barrel carb on it and it ran in the high 14's in the 1/4 mile.
MopaR&D
Nerd Member
I put a Lunati Voodoo 256/262 cam in my 318 along with 302 heads and an iron 360 4-bbl. intake. However I'm still running stock single exhaust and basically 2-bbl. carb (ThermoQuad without secondaries) and the torque is just as strong down low, if not more than when it was all stock. Still pretty piggy though, those primaries flow less than 200 cfm. and my stock exhaust is pretty banged up.
JoeDust451
Well-Known Member
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What was the specs on that cam? Was this useing the 318 heads & stock manifolds, what else was done to the car to run high 14s?
To directly address the cam idle question, there is some debate on idle sound and quality differences between a stock cam and this particular Summitt cam.
IMO, I think there are a lot of deaf people listening to exhaust notes, tempos and the way the system will chop chop chop in it's new state. (New cam installed) There is a difference! But it will be very small. The Sumitt cam is a very mello one and also has a wide centerline for a smooth idle. Just like your stock 2bbl. cam. Tuning the 2bbl. to it will be very easy as well a 4bbl. will be.
IF your looking for a chop to the exhaust, look for a cam that has a centerline of 110 or 108. The lower the number, the more chop it will have.
Tell me this, what is the final plan for the 318 in it's performance goal?
I can better recomend a cam with this info about where you want to end up and with what mods will be done to the car.
68-73 340 cam was a 268/276 .430/.444 lift cam toolmanmike
Badart
Senior Member
If you plan on going with any lift at all you will most likely want to change your valve springs also or it will run like poo. I am running comp cams XE256H in my 318 and it has a little chop and good torque. 1000-5200 rpm, 106 intake centerline, 447-455 lift.
If you decide to go with a little more lift and want to change the springs I have a new set of Comp 901-16 valve springs that I would sell you dirt cheap. I went with magnums and don't need them.
If you decide to go with a little more lift and want to change the springs I have a new set of Comp 901-16 valve springs that I would sell you dirt cheap. I went with magnums and don't need them.
TheGreenSlime
Well-Known Member
Do not ignore your compression ratio when selecting a cam. It's not all about lift and duration. Intake closing point is the most important factor and will make or break the engine performance. 150 - 160 PSI of cylinder pressure will do well on 87 R+M/2. The low CR 340 cam sounds like a good choice.
Badart
Senior Member
Yeah that too.
Ditto, X3. What is the current ratio and will you be adding new pistons or milling the head?
We had that cam years ago in a basic stock 318 70 Satalite with only a 2.71 ring and it was OK, upper rpm better, not much loss in the low end, ible was good not much more than a stock cam.
With that cam I recall the vacuam at an idle was about 3 psi less, brakes were still fine and you may find you need the reject the carb etc. But the questions above are what need to be asked and resolved.
Purpose of use, other mods, gears in car etc...
With that cam I recall the vacuam at an idle was about 3 psi less, brakes were still fine and you may find you need the reject the carb etc. But the questions above are what need to be asked and resolved.
Purpose of use, other mods, gears in car etc...
thanks for all the quick reply. i eventually am going to add 4bl and headers already had the heads shaved and new valves and springs installed. not looking to race just alittle more go and maybe some sound. i called lunati cams and they recommended the 00042 brackedt 2 cam said it would give a little noticable idle and work with the stock valve train with no mods.duratio@50 218/218 gross lift .458/.458 lsa/icl 110/106 rpm range 1500-5000 rpm. i think ill get this one any insight would be great
That will work well with stock (Hwy,) gear ratios and tire size. You get a lil' and nice power improvment.
got all buttoned up sounds and runs great with the lunati bracket master 2 and their people were very helpfull. but bought the cam from summit at a way loer price:-D
MopaR&D
Nerd Member
We need some sounds of course....
if i get a chance ill try all i haves a cheap camera. just had cherrybomb extremes put on to replace the cherry bomb glasspacks. sounds awesome and got me almost 2mpg boost
www.youtube.com/watch?v=0BP8Gp4idWE here is the link to my car, the video isnt good quality but at least it gives u an idea of what it sounds like
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