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a shade tree mechanic
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Discussion Starter · #1 ·
I am in need of some help on choosing a camshaft. I have a 383 stroker. I am building it for a truck I use in mudd bog competions. I would like to know what would be the best camshaft set up I could get as far as turning some rpm's in the mid 6000 range. Any help would be greatly appreciated. I would like it to have a decent torque curve also.

Thanks,

Chris
 

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Pure American Muscle
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You might want to look at the comp. cams magnum line. With a 383 you can suck up some bigger cam and still produce tons of TQ down low but that's only if you have enough CR which im not sure what that is. If in fact you do have around a 9.1:1 or so compression then your set.
I don't know how all your engine is set up but the 280H and 286 even the 290 are all in range.
Also going to the extreme energy cams the larger 274 cams and such would work well.
The 268 is of course everyones fav. but to me the bigger cubes you should go bigger with the cam to make sure that you can get to 6000 and still have a ton ot TQ on hand.
I think the magnum cam would help produce an even curve and give you great power unless your heads are really bad flowing in which case the extreme energy is your better bet.

Thats just a start but the best idea would be to call comp. cams and tell them your set up.


Chris
 

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http://teamrfc.gospelcom.net
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I dont know if you are planning on running a solid cam or not, but comp offers a puller/mud race selection of solid flat tappet cams. I think the 285B-6 (250 260 @.050 .532 .555 lift 3000-6500 RPM range with a 106deg lsa) would work well assuming the rest of your parts are able to operate in that range.

Adam
 

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cam shaft

I believe I would go with a cam that has an advertized operating range of 2500-6000 rpm.

A cam with this rpm range will still have some decent bottom end and yet will turn well over 6000 rpm, probably as much as 7000, with out a major power loss. With that kind of rpm in mind, I would definately recommend some good stout valve springs that will handle the high revs. A solid lifter cam would be a very good idea.

Comp Cams 294S would be a good base line cam to work with.

2500-6500 rpm range

248/248 duration @ .050"
.525/.525 lift
110 lobe separation
 

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Hotrodders.com Moderator
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inquiring_mind2 said:
I am in need of some help on choosing a camshaft. I have a 383 stroker. I am building it for a truck I use in mudd bog competions. I would like to know what would be the best camshaft set up I could get as far as turning some rpm's in the mid 6000 range. Any help would be greatly appreciated. I would like it to have a decent torque curve also.

Thanks,

Chris

Chris, choosing a camshaft for competition situations isn't something you can really guess at. You probably need to give more information to us before any of us could give you any type of decent answer concerning what cam profile to use.

How heavy is your truck? What class are you running in? What type of gear ratio?, Automatic or standard transmission? How much static compression ratio do you have? What type of cylinder heads are you using? What type of intake manifold? What type of carburetion/induction are you using? Nitrous?

All of these variables, and there are alot more, would dictate what to use.

Your choices could be a street type performance cam if you have a basically stock type engine.

If you have "racier" equipment, you can utilize a more radical profile, it all depends upon your combination of parts.


Brian
 

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a shade tree mechanic
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Discussion Starter · #6 ·
camshaft

Hello Brian,

The classes are based on tire size in Illinois. I run a 35 inch bogger. My truck probably weighs between 4000-4800 lbs. I run a 488 gear ratio, with an automatic trans. The engine has a 10-1 compresion ratio with Dart Iron Eagle heads. Valve size 202 160. Right now I have an edelbrock Torquer 2 intake, however I am probably going to change it to something else. I haven't decided on it yet. If you have any suggetions let me know I would appreciate it very much. The carb is a Holley 780 dual feed. If you need more info let me know. This should help you out some.

Thanks,

Chris
 

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If I understand bogging to be basically an all out race, I think that you could set it up to handle a pretty nasty cam. From what I understand it is like a drag race in the mud. The cam that firestone pointed out would make alot of power, but you are going to suffer in the low end. You will need a high stall convertor to make it work properly. A 10 inch with around 4000 RPM stall would certainly clean the tires out nicely.:) I would also look into a little better intake like the victor jr. The torquer II will work, but they were never famous for putting up great numbers.

Whatever you do, I would go with a 106 duration cam so you can get a strong narrow powr band. For racing, that is the only way to go. But, that will make the convertor swap an absolute must.

Chris
 

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a shade tree mechanic
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Discussion Starter · #11 ·
Hello Tornado Tech,

The engine I am running a 383 stroker motor. The engine has 10-1 speed pro pistons. scat rods. it has dart Iron Eagle heads. The valve sizes are 202 160. 68 chambered cc. Right now I am running a edelbrock torquer 2 intake . That is going to be changed but to what I haven't decided yet. I am running a Holley 780 dual feed carb. I am using a TCI stall. It is a 2800-3200rpm stall. the rules are simple no nitrous and the classes are run by tire size not motor size. The are no vaccum rules what ever size motor you come with is what you can run. I hope this is enough info if not let me know what you need and I will send it to you.


Thanks,

Chris
 

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OK. Are you sure on the combustion chamber size? Dart only makes them in 64cc and 72cc. With the 2.02 valves, do you got the 165's, 180's or the 200's? Also do you have 1.25 or the 1.437 springs? Are the pistons 2-valve flat tops? I am leaning to a roller to maximize horspower but need the above information to make final suggestion. According to the rules, you are in a very tough class. In Kansas, that class is dominated by S-10's or Toyota's bodies on Blazer frames with 500+ cubes even though some runs have a stock class that allow 35's but they have some kind of restrictions. Let me know the abovew information and I will try my best to help you.

Tim
 

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a shade tree mechanic
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Discussion Starter · #14 ·
Hello Tim,

thats right I was wrong They are 64 cc with 180 runners. The springs are 1.25 however I am buying new ones with the new cam I am going to run. The springs are rated for a 500 lift. I am planning to go more than that I would like to get something between a 550 and 600 lift. The pistons are 2 valve flat top. I am in a very tuff class. I would like to switch to an s-10 body style, but right now I'm getting the motor together first. Then I will look into the s-10 body. The cam I have in it right know is a 488 lift with rpm range of 2200-5200. It worked ok but I want more rpm's to try to get the tires turning a little faster. Do you have any suggetions on a intake right now I am running an edlebrock torquer 2 but I want to change to something else.

Chris
 

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Are you sure of the combustion size? Dart makes the Iron Eagles in 72cc and 64cc. With the 2.02 valves, are the head's intake ports 165, 180 or 200? As any port work done to them or are they as-cast? Do they got the 1.25 or 1.437 springs? Are the pistons 2-valve flat-tops? Im leaning to a solid roller to get you as much possible hp. By the rules, you are going to need every bit of hp and wheel speed you can get since I see S-10's or Toyota bodies on top of Blazer frames running 500+ cubes. That is what dominates a class along those guidelines here in Kansas. I will try and help you out as much as I can.
 

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a shade tree mechanic
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Discussion Starter · #16 ·
hello Tim,

The heads are 64cc and the intake ports are 180. There has been no porting done. The valves are 2 valve flat tops. the springs are 1.25. but I am buying new ones. The old ones are only rated for a 500 lift I want to go around 550 or 600. I want to get as many rpm's as possible out of the cam I amputting in I also would like to have some low in torque as well.


Chris
 

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I would try to get the compression as high as you can. A heavy angle mill down to about 57 CC or less would be a good start. The CS285B-6 is kind of like a baseline circle track cam that lots of people use. I probably would go for a specific mud grind, but definitely a much more race orientated solid grind. I would use a Victor Jr. and probably go with a 850 double pumper. If it were mine, I would want 12.0:1 compression minimum, but with flat tops, you are limited as to what you can do. Compression is king in racing engines, particularly with under-valved 383-400 inch small blocks.

With a flat tappet cam, you should be right around the 500 horsepower mark if things are well matched. You could get more power, but I feel like 500 horse is going to be your benchmark.
 

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With the 180 heads, they top out about .525-.550 as in an as-cast version. You should have about 10.7:1 compression with your combo. With the stall you got, I'm looking at the same as everyone else (285B6). That should be a very good cam for your combo. I definitely recommend a better single plane like a Victor Jr or a Team G. I hate to say this but those heads are a little small for a good 383. You would benefit from a bigger cc head with a smaller combustion chamber. If you had a set of 215cc heads, than I look at the 288AR-6 but this cam is too big for your current combo.

Good luck in your mud endeavor
 
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