Cam Suggestions

[rharrell]

Can somebody please explain in laymans terms, "RV cam"? I have put a new Weiand Action-Plus intake, Holley 570 Steet Avenger carb., Performance Dizzy on a otherwise stock 302. I want better low end torque, mileage if possible. Use is street and occasional mudding here in the Bayou State. Would I have to replace anything else? HELP I am out of my league!

 

[blubuckaroo]

I just put an Edelbrock Performer cam in my 302 Edelbrock Performer intake and 500 CFN Edelbrock carb. It's a generic RV cam. The same grind is available in a lot of places under other names. Summit sells the same thing. The only reason I spent more and went to Edelbrock was the warrenty. Edelbrock also provides a complete set of instructions. Whatever you put, make sure you use an oil that doesn't have reduced zinc and also add a bottle of break-in additive from Crane or CompCams durring break-in. I used Castrol GTX on my first attempt and wiped two lobes in the first 30 minutes.
If you have a pretty much stock motor then this is the most cam you will want because if you put in something more radical, you will need to put in threaded rocker studs and guide plates. This cam grind will wake up your motor substantially without a rough idle.

 

[fordtrucksrule]

im getting ready to go with the edelbrock performer cam kit as well as a petejackson quiet wont ever have to worry about chain stretching

 

[broncnaz]

RV cams are generally lower RPM cams made for heavy vehicles that dont need to go fast. They make there power down low and are usually good for towing and mileage. While the performer cam is a good generic grind it may not be exactly what you need. Call a cam company and give them your specs and what you want out of your engine. I've run cams bigger than the performer in my 302 with good results and needed no other parts. Although some cams require different springs. threaded studs and hardened pushrods with guide plates are kinda like insurance but not always needed with bigger cams.
One other thing you need a good exhuast system to maximize any of your current mods and especailly if you swap in a cam. at the very least you need bigger pipes coming off the manifolds. Headers are the optimum choice though.

 

[feitctaj]

Can somebody please explain in laymans terms, "RV cam"? I have put a new Weiand Action-Plus intake, Holley 570 Steet Avenger carb., Performance Dizzy on a otherwise stock 302. I want better low end torque, mileage if possible. Use is street and occasional mudding here in the Bayou State. Would I have to replace anything else? HELP I am out of my league!

The term RV is Recreational Vehicle , thus it will pull better in the low end and keep you from having to overwork your engine to get pulling power.
Generally the RV cams pull from Idle and fall on their face at 4500 to 5000 RPM and yes they are made to get a bit better mileage than stock when using a heavier rig. Cam kit will come with lifters too

 

[oleguy74]

rv cam term has ben around for 35 years.started 1973.iski ,and crower were the first to advertise them.iski - mile-a-more,guarented a mile or more a gal increase.crower,gas strecher.high torque at off idle to about 4000 rpm.quite a bit of engineering but baisicly high torqe at lower rpms.off-road stuff,and hi-way.

 

[oleguy74]

cams

from 1974 iski catalog

 

[Wyldebill]

You are wanting your tourque to maximize in your lower RPM range I presume. When you want low end tourque, you need to build your air intake system, (ports,valves, cam, manifold, carb, and air filter) to maximize velocity. Meaning the method of getting more air/fuel into your cylinders should be by using methods exactly opposite of Hot-Rodding practices such as larger valves/ports/carbs and manifolds. These things along with a high lift, wide duration/overlap cam shaft will do wonders for increasing the volume of fuel/air flowing through your engine and will result in great horsepower increases, but because you have also increased the total volume of your system, it will require high-high RPMS to move the air at enough velocity to feed that horsepower. The key to keeping your tourque range in the lower RPM range of your engine, is keep your ports stock in size or even smaller if there be a set of heads that will fit your block and used smaller ports. A serious clean up and polish on said ports will be highly benificial though as well as retaining the stock valve size. The question of what is an RV cam ? is simplified down to this, generally it is a cam that will have a reasonably high lift and a mild duration. The real key is that an RV cam will have little or even "0" overlap, as overlap will cause the engine to lose most of its low end vacum which will kill your fuel/air velocity. Remember you are not building a lot of RPMs like a horsepower engine would to build that required velocity. I see that you are using 570 cfm carb which should be good on a 302, and I am not familiar with your intake, but if it is for "high-performance," it may not be your friend in the quest for low end tourqe. If I am changing a cam or building a motor, I will always use an RV cam inmy trail machine. Second choice - a stone stock cam will give you a lower tourque band than any performance cam. Any performance cam you might choose will always move your touque band up in the RPM range, but it will usually increase your available tourque noticably if you are willing to use the skinny pedal to go after it. One last thing, be sure that the RV cam that you select will not have such a high lift that your valve springs will coil bind. The best RV cam that I have used, (sorry, I can't remember the specific cam,) it was a very high lift and "0" overlap and required racing valve springs to accomodate the lift. Thats as "Layman," as I can make it, I hope it helps you out some. Bill

 

[broncnaz]

Wyldebill your kinda contradicting yourself.
The method for getting more torque is pretty much the same as the hotrodding mods just not as extreme.

SBF's are known for there horrible exhuast ports the overlap in cams is needed to help push exhuast gas out the small exhuast ports. so the zero overlap is not ideal for SBF's. There are very few SBF cams offered with zero overlap. If Keep the cam duration below 218 at .050 your usually fine. My current cam has a little less than 218 and even with TFS heads and a single plane manifold I pull 17in of vacuum at idle and have more lowend than I did when it was stock.
A small increase in valve sizing really does help SBF's. Porting is really only needed on the exhaust side. while port matching the intake to the head will help. Dont polish intake ports. You manifold will help as the longer runners help build velocity.
one other thing to remember is that when EB's were built the speed limit was only 55mph thats where the power was with the stock cam. They were also built during the big push on emissions which also resulted in poor stock cam profiles. a aftermarket cam will move the power band up and is usually needed with todays speeds. But will also make more torque down low than the stock cam.

 

[wildbill]

The best you can do is call the cam co. of your choice and tell them what you have. They will let you know wich cam is best for you this takes the O sh%% out of it. I have had the best luck with Erson cams good luck and have fun. Bill %) ;D

 

[needabronco]

I think you need to evaluate what you want. You say you want low end torque, and you want to run bayou mud, those two scenario's seem to me are two different requirements.

I run a performer cam and I really like it but yes if falls off fast past 4-4500rpms, it's alittle better with efi, but my efi intake is more efficient.

If you want to run in mud, I assume you need a higher rpm cam like say a performer rpm cam. This is still a good choice, but you will give up some of the performers' off idle torque.

You also will need to match your intake manifold and carb cfm to your cam. Your Weiand intake and 570cfm carb will work well with the regular performer type camshaft.

One other thing to consider, if you think you will ever switch over to an efi setup, I'd suggest you look at the 351 cams. The only real difference will be the firing order and it'll match the efi firing order when you do the swap.

Like others have said, your best bet is to still research the cam you need and talk to the tech lines and get their recommendations.

 

[NYLES]

The best you can do is call the cam co. of your choice and tell them what you have. They will let you know wich cam is best for you this takes the O sh%% out of it. I have had the best luck with Erson cams good luck and have fun. Bill %) ;D

Well said......cept I like Comp!

 

[rharrell]

Thanks to all. I recently dropped the oil pan, changed the oil pump and noticed the the cam in my truck. I know it sounds stupid, but it really didn't look all that difficult to "unbolt all the pistons from the cam" and change out the cam. I know it is not that easy. If I went with the Edelbrock performer cam, what else would I have to change? I see where they come in kits with new pushrods and lifters, but is it necessary to change all this as well. And just how difficult would it be to put in a new cam?

 

[feitctaj]

thats a crank not a cam and buy the cam kit with lifters and pushrods
the cam is above the crank

 

[rharrell]

Well said......cept I like Comp!

Nyles, Which Comp cam do you have in your EB?

 

[rharrell]

thats a crank not a cam and buy the cam kit with lifters and pushrods
the cam is above the crank

Well maybe that faux pax should tell me I need to rethink my plans! Hell, I don't know the difference between a cam and a crank! Thanks for pointing that out.

 

[NYLES]

262 Extreme Energy...NOT the 4x4 Extreme Energy their on different lobe seperations

Next choice would be a simular Lunati VooDoo.......then on to a roller

I love RRRRRRR's no crawlin for me!

 

[feitctaj]

Well maybe that faux pax should tell me I need to rethink my plans! Hell, I don't know the difference between a cam and a crank! Thanks for pointing that out.

no worries, I just wanted to set you strait cause that crank needs t;D be left alone if you want to get more low end;D

 

[Baja71]

As a comparison, I bought but have not run yet, a Ford Motorsports block that came with the Explorer cam. It's specs are:

Explorer high torque hydraulic roller camshaft

– Intake .422", Exhaust .448"
– Intake 256º, Exhaust 266º
– 116º Lobe Separation

 

[rharrell]

Ok, I took stock on everyone's suggestions. I am looking at the Lunati Voodoo cam for the 351W. It has a different firing order than my 302. Other than moving the spark plug wires to different locations on top of the dizzy, what other changes are needed?