Whats a cam do?

[Motorhead350]

I was thinking of throwing a cam in my Blazers Ram Jet 350 engine because it seems to fall on it's face past 3,000 rpm. I know the solution is a new cam, but what exactly does it do? Does it add horsepower or does it just distribute the power differently kinda like changing your gear ratio..... maybe my example is a little off, but you know what I mean. I was thinking of putting a cam in it and spraying it too. It already has 350 Horsepower, but I wanna run 13's for less then $1500 if I can. I think it runs close to a stock Marauders time sense I beat my own Marauder with it to 60 (someone else was driving my Marauder) so anyway what does a cam do and can it be easily installed into a fuel injection engine or do I have to buy a whole new engine management system.... if thats the case then I'm passing.

[fastblackmerc]

Best thing to do is to call one of the major cam manufactures like Crane, Comp Cams, etc., and talk to them about what you want to accomplish. You can get a cam that increases low end HP & TQ or increases high end HP & TQ or gives you a little of both. They'll be able to provide the info you need to make an informed decission.

[Paul T. Casey]

Bad news for you. Cams, as with any modifications on a computer controlled fuel injected vehicle, will require a new tune to yeild optimal results. The new cams will control the ammount of time the intake and exhaust valve are open, how wide they open, and that sort of thing. You will need to adjust things like your ignition timing, fuel pulse length, etc. to match what your valves are trying to accomplish. Upside here is you should be able to update your current program rather than buying a whole new management system.

[Motorhead350]

Is there a simple plug in like a Microtuner that can do this or would I need that Holly Commander?

[Vortech347]

That K5 dosn't need a computer reprogram. Its an OBD-1 computer. Extremely basic. There are no plug and play's for it, unless you do some sort of stand alone management.

The cam in that K5 stock was designed to get good low end power along with good mpg for crusing. As recommended you could talk with a cam company about what to do. But with stock heads a different cam won't be of much help for all the labor involved. If you want more umph you should look into a heads/cam package. That would realy wake things up.

Before dipping that far into the engine....

Get a better carb,
Full Length headers,
Roller Rockers,
Underdrive pulley's,
MSD 6 Series ignition

Go from there.

My friend has a Wheelin 89 K5. The difference long tubes, a good y-pipe, and catback was huge in the entire powerband!

[dwasson]

There are usually a lot better "bang for the buck" mods that you can do before you replace the cam. The post above talks about specifics.

[Motorhead350]

http://www.jegs.com/webapp/wcs/store...tegoryId=10763
That is the engine that I have, it's fuel injected and is pretty solid, but falls on it's face past 3,000 rpm, then again my truck does weight 4,839lbs.

[Motorhead350]

Now I just heard of it's EFI I don't need to buy any form of aftermarket computer.

[Breadfan]

Now I just heard of it's EFI I don't need to buy any form of aftermarket computer.

Depends, a stock K5 of that era might not, but I assume that motor came with a standalone engine management system. I don't know what kind or how powerful it is. Do you know if its ODB1 or ODB2?

I would expect in a crate motor like that the cam would be matched to the heads. I thought the iron vortechs could flow pretty good. If you upgrade the cam you may want to atleast get a port/polish on them to clean them up.

You should call a cam company and let them know the engine you have. See if in the documentation it lists the cam specs. Then tell them what you'd like from it and I bet they can tell you a grind best for your setup, including the heads and other mdos you have or have planned.

[David Morton]

So, I'm guessing this means your transmission problem has been solved.

Don't be suprised if it comes back after all this is over. If you're planning on adding a lots more power it may be more than the factory tranny can handle.

[Motorhead350]

No the tranny has not been solved. I'm just thinking of doing the cam over the summer. I can still drive it and know how to avoid the problem with the torque converter kicking on and off, but it's still a real pain! I just got it back again and now my brake lights won't turn off!

[Vortech347]

OBD-II didn't come out till 96...

[David Morton]

No the tranny has not been solved. I'm just thinking of doing the cam over the summer. I can still drive it and know how to avoid the problem with the torque converter kicking on and off, but it's still a real pain! I just got it back again and now my brake lights won't turn off!

Your comment here reminded me of the biggest problem with this tranny, running with the TC clutch off for too long a period of time. This is when the TC makes a lot of heat. A really big cooler is just about the only way to go to solve most of this problem, especially in a big vehicle like the K5.

Your brake light switch is out of adjustment. This will make the problem of the TC heat worse because the brake light signal to the computer will cause the computer to turn off TCC. As long as those lights are on, TCC will be off.

[1madmarauder]

hey man like ive said before with the exception of my mm, im a chevy guy. a cam will do huge things for and small block with vortech heads, the vortech head has superseded even the GMPP bowtie race head in flow. the question is which heads do you have and how much cam lift will they clear? i put a comp cam .490 lift in a crate 4 bolt main 350, with a 600 hun. cfm holley and headers and it rocked! a rule of thumb is to not go overboard. the idea is a combination that works together, no use holding the valves open longer than what cfm they will flow. btw, a stock vortech head with no polishing or porting will flow about 265 cfm. valve springs will need to be chavged with any performance cam swap, and the wrong ones usually come in the cam kit. youll have to take a valve cover off to see if you have the large diameter spirngs or the small ones, either way make sure of that, valve springs are importan to this equation..................larr y

[Motorhead350]

I have iron heads as you can see in the link I posted and I fixed the brake lights myself. I just pulled the brake petal up so I guess it was stuck down a little bit thats all. I'm taking it to the today and we'll see how it does. I'm hoping for anything in the 15s but a 15.5 or lower would be nice. Like I said it's a killer off the line, but past 4,000rpm it falls hard.