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post #1 of (permalink) Old 04-30-2002, 08:11 PM Thread Starter
 
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**NEW PLAN** To cam or not to cam?

Ok... I bought a bunch of stuff for my truck... Edelbrock Performer Intake and Performer Carb (w/offroad needles and seats[img]images/icons/smile.gif[/img]) and a new distributor. So, I'm talking to a guy about putting this stuff on for me and he suggests that maybe I should think about putting in a cam, too. He tells me... "you will DEFINITELY notice a difference with a new cam". Just when I thought I had it all worked out ... now I have this new dilemma.

So, my questions:
1) do I really need to do this (cam thing)?
2) if I do decide to do it, how do I figure out which cam to get?
3) how big of a performance gain is there and will I have to worry about upgrading other things with this addition?
3) is it that much more cost effective to have the cam put in while he's doing the other stuff (i.e., less labor involved)?

As usual, your suggestions and comments are greatly appreciated.
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post #2 of (permalink) Old 05-01-2002, 12:03 AM
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Re: To cam or not to cam?

A camshaft can make a real difference in performance and a huge difference in a bank account balance when considering labor cost. I'd suggest going for the intake manifold, but I'm not a fan of the Edelbrock Performer carburetor. I'd suggest using a quadrajet carburetor (kinda expensive I know [img]images/icons/frown.gif[/img]). A calibrated distributor can make a very noticeable difference in engine performance also. I'd suggest having a HEI distributor calibrated for about 14 degrees BTDC at 800 RPM's and a total advance of about 28 degrees BTDC at 3000 RPM's. A good flowing exhaust system helps also. A single 3" exhaust is good, but a less expensive dual exhaust system using 2 1/4" is also good. Mufflers can also help performance, lots of good budget options for good performance mufflers, I would not recommend using glass pac mufflers. Headers are good, but require regular maintenance, so headers are not for everyone. For the budget performance mods, just improve the way the fuel/air is moved in and out of the engine. Make sure the engine is tuned up correctly, and I'm sure you will be pleased with the performance.
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post #3 of (permalink) Old 05-01-2002, 02:58 AM
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Re: To cam or not to cam?

1) No.

2)Thatīs easy[img]images/icons/smile.gif[/img]. The one and only cam for a 4x4 pickup is a mild one from the Competition Cams Xtreme 4x4 series or Xtreme Energy series. Do NOT let your friend talk you into any other cam [img]images/icons/crazy.gif[/img].

3) Thereīs a difference alright. Youīll gain maybe 40 ft.lbs of torque & 30 horsies while getting better mpgīs. So eventually itīll pay itself off. With a new cam you always buy new lifters. Ususally you can buy cam and lifters as a kit, and save a few $. If you wanna go by the book you also get new valvesprings, timingchain and *gulp* new cambearings. If you have to change cambearings then itīll get tricky. Special tools and knowing what to do is an absolute must here. The cambearings go in a special order and can not be mixed up.

4) Well, yes. When you change a cam you have to remove the intake, and thatīs what youīre doing right now so.....

Summit has a cam-kit with Comp Xtreme 4x4 camshaft, lifters, valvesprings, retainers, locks, valvestem seals, timingchain and assembly lube (and decals[img]images/icons/smile.gif[/img]) for $270. Partnumber is CCA-K12-231-2. Check it out. Or you could just get a cam and new lifters for $170 and forget about the rest. Your stock valvesprings will handle the extra lift but they might not handle it well when the rpms are up. You can be REAL picky but the question is; is it worth it, considering the rest of the engine/truck? I bought matching valvesprings for my engine but thatīs with a higher lift cam and the d*mn thing is $4000+. I donīt wanna take any chances [img]images/icons/smile.gif[/img]. My truck doesnīt deserve the 406, haha.

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post #4 of (permalink) Old 05-01-2002, 12:37 PM Thread Starter
 
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Re: To cam or not to cam?

Dave -- I've already got headers and dual flowmasters... so that base is already covered. The distributor I bought is a brand spankin' new HEI from Summit and the intake and carb are already purchased. I've also heard some bad things about the Performer carb, but my mod consultant tells me that with the offroad needles and seats, it works just fine -- I trust his advice, so I'll stick with it for now.

What I can gather from your post is that you don't think it's necessary? That I'll be happy with it without a new cam? Sorry, I know absolutely squat about this stuff, so please forgive my ignorance[img]images/icons/tongue.gif[/img].
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post #5 of (permalink) Old 05-01-2002, 12:44 PM Thread Starter
 
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Re: To cam or not to cam?

Andreas -- I thought my post might pull you out of the woodwork! Good to see you here and thanks for the reply[img]images/icons/smile.gif[/img]!

Anyhow, the cam thingy is tempting... VROOOM[img]images/icons/cool.gif[/img]. The guy gave me a list of parts to get and he owns a shop, so, I'm pretty sure he knows what he's doing[img]images/icons/crazy.gif[/img]. I guess I need to make a list and see how much all this stuff is gonna cost before I make my final decision. Thanks again, brat.
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post #6 of (permalink) Old 05-01-2002, 04:21 PM
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Re: To cam or not to cam?

Yes. I only wanna talk about engines thank you [img]images/icons/laugh.gif[/img].

A somewhat cheaper and easier performance upgrade is getting roller rockerarms. Ranging from $80-90 to $300. If you decide you donīt wanna go trough the cam-thing you could get 1.6:1 roller tip rockers, which will increase the lift without affecting duration (well, maybe 1 degree [img]images/icons/crazy.gif[/img]).

Letīs start from the beginning [img]images/icons/smile.gif[/img]. The spec named "lift" is how high the cam lifts the valve. If nothing else is mentioned it means lift at the valve. You might stumble across some cam that has lobelift specs, and thatīs how big the lobe on the cam is. Then, to find out how high the lobe will lift your valve you just multiply it with the rockerarm ratio (stock 1.5:1). Example. lobelift = .300" multiply that with rockerarm ratio (1.5) and you find out that the valvelift is .450" (.300" x 1.5 = .450"). And what happens if you replace your old 1.5 stock GM rockers with shiny new 1.6 ratio rollerrockers? Yep .300 x 1.6 = .480". Godd*mn beautiful![img]images/icons/cool.gif[/img]
Now, duration is just a fancy word for how many crankdegrees the cam does its thing [img]images/icons/smile.gif[/img]. For how long it holds the valve open. You will often see two values here (or actually four values). One is advertised duration and the other is @.050 lift on the intake and exhaust side. Iīm not gonna go into this because I donīt completly get it myself[img]images/icons/smile.gif[/img]. Basically it lets you know how agressive the lobes are.

Okay....do you have a headache yet?[img]images/icons/smile.gif[/img]

Andreas
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post #7 of (permalink) Old 05-01-2002, 04:27 PM Thread Starter
 
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Re: To cam or not to cam?

YIKES!!!! Yes, I have a headache!

Ok... so tell me more about the roller rockerarms. What sort of performance gains are we talkin' about? Is this easy to do with the mods I already have planned? (i.e., not much more labor?)
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post #8 of (permalink) Old 05-01-2002, 05:26 PM
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Re: To cam or not to cam?

Well, the performance gains is maybe 8-12 hp if you go with roller-tip 1.6 ratio. Ads talk about 25-30 hp but I donīt buy that for a second. Maybe with full rollers 1.6:1 ratio you get 15-18 extra ponies, but itīs $300 for full rollers and you can get a cam-kit and money over for mayo[img]images/icons/laugh.gif[/img] for that $300. With roller rockerarms youīre also much nicer to your valvestems. Itīs a simple operation and you only need to remove the valvecovers to access the rockerarms.

The chef
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post #9 of (permalink) Old 05-01-2002, 06:31 PM
 
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Re: To cam or not to cam?

Cheryle, check out this link; has a good picture of what Andreas started talking about.

http://www.compcams.com/Information/Tutorials/
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post #10 of (permalink) Old 05-02-2002, 08:00 AM
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Re: To cam or not to cam?

Cherlye,
I guess I wanted to say, if your budget is kinda limited, the performance improvements you have plan to install / have installed will help performance. The labor cost of a camshaft change makes the dollar per horsepower gain sorta expensive.

If you were able to install the camshaft yourself, I'd flat our recommend the camshaft change. I'm not positive the new Summit distributor is calibrated to curve I described. Usually the only feature the Summit distributor has is an adjustable vacuum advance, which will only change the rate of timing advance. The type of distributor calibration I describe will require the distributor to have a much different timing curve than the Summit distributor can offer. Check out the following link<a target="_blank" href=http://www.boyleworks.com/ta400/psp/distcurve.html>http://www.boyleworks.com/ta400/psp/distcurve.html</a> for a better explaination of changing the HEI timing curve. Sorry the site is for a Pontiac, but it's still a GM HEI distributor. If you thought a camshaft change will hurt your head, the distributor stuff can be just as head hurting.
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