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Old 05-27-2003, 05:59 PM
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Post camshaft help

I need some help with choosing a cam for my motor. I have a 350 with a stock bottom end and 1.94 heads. Right now I have an rv cam in it, 204/214 @. .050 420"/442" 112 LS. I have and edelbrock intake, a quadrajet carb, headers, and exhaust. I want to go with a different set of aftermarket heads and a cam to give me a little bit more power. It's bolted to a th-350 with a shift kit and a stock torque converter, rearend will shortly be a 3.23 posi. Everything is new with about 4000 miles on them. For the cam, I was thinking about going with a crower cam, 220/226 @ .050 462"/470" 112 LS. It is the crower 280HDP cam. How does this cam sound to you guys? I do do a lot of street driving. How do you guys think this will compare to something like a comp xe-262 cam. Any help is appreciated.

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Old 05-27-2003, 07:11 PM
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224 duration is the biggest cam you can go with out a stall stay under about 470 lift with stock convertor.I'd run a 224 duration 465 lift.but do some work on your heads spring's seat's 1.6 rocker radio your lift will go to about 490 to 505
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Old 05-27-2003, 08:09 PM
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Can someone explain to me why 224 duratioin and .470" lift is the highest you want to go with a stock converter. Wouldn't a 220/226 duration cam work with a stock converter? Also would you recommend going with 1.6 roller rockers or staying with 1.5?
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Old 05-28-2003, 07:31 AM
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If you run bigger than a 224 duration when you put your car or truck in gear .It will start pulling and going forward It might go dead you need a stall. You might get away with out useing a stall. Hop this helped.
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Old 05-28-2003, 08:00 AM
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[quote]Originally posted by novatech:
<strong>I need some help with choosing a cam for my motor. I have a 350 with a stock bottom end and 1.94 heads. Right now I have an rv cam in it, 204/214 @. .050 420"/442" 112 LS. I have and edelbrock intake, a quadrajet carb, headers, and exhaust. I want to go with a different set of aftermarket heads and a cam to give me a little bit more power. It's bolted to a th-350 with a shift kit and a stock torque converter, rearend will shortly be a 3.23 posi. Everything is new with about 4000 miles on them. For the cam, I was thinking about going with a crower cam, 220/226 @ .050 462"/470" 112 LS. It is the crower 280HDP cam. How does this cam sound to you guys? I do do a lot of street driving. How do you guys think this will compare to something like a comp xe-262 cam. Any help is appreciated.</strong><hr></blockquote>

The crower cam you've mentioned will be fine on a stock converter, as will an XE-262 (I should know, I have one) although you may well get better response with an 1800-2000 stall converter (bought one, just need to fit it).

The two camshafts you've mentioned will be fairly similar just looking at those numbers, but the comp cams XE range are noted for their aggressive ramps so may well produce more power than the crower (you'd need to compare duration @0.006" as well)
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Old 05-28-2003, 07:38 PM
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I would suggest the 262 or even the 268xe grinds by comp. That's only because I've heard about them, and I am not familiar with the others.

Now, about this your vehicle will roll and might choke and die... I don't know where that was going.

Look, if you add too much duration it will, of course, decrease your bottom end torque and add more hp. If you add just the right amount both will go up.

The reason you would want to run a higher stall converter is because you're not going to have low-end grunt. Like, if you ride in an LS1 car, it takes off moderate, but once it gets going well-then, it's all hades breaks loose. It's the same thing. Your new powerful cam will take off markedly slow, but when it's in it's "sweet spot" it will then pull better.

A torque converter works like two fans. If you have a oscillating fan and you position it to blow on another fan that isn't on, the other fan will be caused to move by the fan that is on. That's how a torque converter works. Your engine is fan #1. It spins, and once your engine revs reach a certain speed fan#2 (transmission input shaft) starts to spin.

In a stock converter, they will hydrostatically (they have transmission FLUID in them, hydro=fluid) lock together at a low speed. This means you might get close to 1:1 at 1600 rpm. Now being your stock engine made good grunt at this low engine speed, that isn't a problem. With the new cam you can potentially loose some low-end torque. This will cause you to make less power at the lower rpm speeds. So, what worked fine at 1600 rpm before doesn't cut it now. Your engine is missing and isn't running smooth and powerful. If you try to take off with not enough stall you engine and transmission will be connected and your engine is going to have to really struggle to spin, and it will have to struggle even more to gain rpm's. Once it does overcome this and get up to a certain engine speed it will accelerate fine.

So, if you get a converter with a higher 'stall' speed, you will move that 'hydrostatic lockup' point higher into the rpm range. This means that now at say (if it's a 2500 rpm stall) 2500rpm you get your 1:1 with engine speed and transmission input shaft. This won't snap into action will will be gradual somewhat, but should "flash" close to the full stall rating. Now, say put your vehicle in low and punch the gas your engine speed jumps up to 2150 rpm and that's where you start your engine accelerating from.

You don't have the lowend torque you used to have, but you make more power higher in the rpm range. The converter will just allow you start off higher in the rpm range where you are making more power.

I finally understand this stuff somewhat. If you have questions, post them. I'll answer if they're not answered. Don't be afraid if you need a stall. If you can do a cam you can easily change a converter. You can pick up a B&M converter (2400 stall) for $150. You can get their 2800-3200 stall for two hundred and something.

You might be able to get away with no stall for some cams. Once you get it installed, if it is sluggish off the line add more stall speed.

For the guy that said you car would choke and die. With the stock converter you can take your foot off the brake and the car will roll. With a higher stall converter this will not occur as strongly.

One last point to mention. If you run a high gear like you are saying, you won't turn a lot of RPM cruising. If you get a 3 grand converter you will need to cruise close to 3000 rpm, or it will slip. If it slips you will waste fuel. Your economy can suffer. Converters that slip also make a lot of heat. Heat is what kills your transmission. Make sure you put an aftermarket cooler for your tranny.

So, if you're not willing to run more of a gear, don't get a big cam. You'll need a bigger converter and you won't cruise at enough rpm to do so economically.

You really should make a cylinder head choice before you buy a cam. People who have seriously fast cars do that. They pick their heads, and then send them off to be ported and flowed. When they get the flow numbers they have a custom ground cam that will keep up with the heads.

Make your head choice first. That way, you only have to do the cam once.

If you have large intake runners on your heads, that's the same as having a big cam. For instance the torquey Vortec heads have a 170 cc intake runners. Small block race heads could have 240cc intake runners. Go for a conservatively sized runner, and pick a cam that will make power in the same area.

Sorry if this is too long. It's almost over.

220/226 @ .050 462"/470" 112 LS

That's the cam you want.

Right now I have a 212/222 with .435"/.460" on a 112LCA. My cam is in a 350 with 9.1:1 compression. I have a 2400 rpm converter with 3.43 gears and a th400 tranny. I feel like I need more converter. If I had more, I'd leave the line harder. That's a fairly aggressive cam you have picked out. You'll hear a noticeable lope with that one.

Also, you'll need around 9.5-ish:1 compression if you want to run a cam like that. You can do it with less, but that will hurt your bottom end torque. You'll want to get at least 9:1 compression or more. I don't know what your compression would be with the stock bottom-end, but if it's in the eights that should be addressed as a concern.

What heads are you considering?

Hope this might have answered something.
Post any more q's.

Ben T.
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Old 05-29-2003, 07:17 AM
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Hey Muscle truck, Is your cam the GM grind 330hp crate motor cam? If so does it lope noticably and how do tou like it for a street cam? I currently have the GM cam with vortec heads and a GM vortec intake with a 600 edelbrock carb. Mine is destined for a 75 camaro, but right now is sitting in a 72 chevy truck.I have very little run time so far but notice a vibration up to 1500 rpm. Does yours? Also on desktop dyno it shows over 300 ft lbs of torque from 2000 to 5000 rpm but I just don't feel it. Just curious about your setup, any problems or hints?
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Old 05-29-2003, 09:42 AM
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Yes-sir. That is the cam I have.

I like it way better than a stock cam, and for the power it makes it is okay. I get great vacuum and a smooth idle. I essentially notice no lope except for when it is cold and I'm barely rolling-riding the brake. I notice my truck shake then.

How do I like it for a street cam? Well, I have the gm 330 deluxe. I think it's okay for my set up. The cam seems to not be a strong performer down low-this aids in traction. Up top it pulls well. This will be the last hydraulic flat tappet I run on the street hopefully. Unless, I have to make an engine on the cheap- from here on out they will all be hydraulic rollers. I have a swap planned for my engine.

In closing, I wish it pulled harder off the line and sounded better though. I don't get either of those with this cam. The 224/230 @ .050 hydraulic roller will fix that. I'm still trying to decide if I want to go that big. Other option is a 218/224- both on a 110LCA. My heads will be able to keep up with either cam.

Ben T.
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