what cam can i run, i got some extra money for christmas and am looking to buy a cam and was interested as to which one would be a good choice, i am NOT looking for full blown drag performance, i pretty much just want a good overall cam with a descent idle i also am planning on adding a Whipple in the next few months so it has to be compatible with that too, and if your running an aftermarket cam could you still use the larger 1.6 ratio rockers or would the lift of the cam be to much and still make use stick with 1.5 ratio's? also would it be worth it to swap to a full roller velvetrain, or would is be a waste of money. I currently and buying the Edelbrock E-tec 200's and figured while i have it all apart might as well get a nice cam to complement the setup, if i were to get a higer lift/duration cam would the springs on the E-Tec's be able to hold up to them? i know a few people on here have the same setup that i am going for and would like there imput thanks

Matt

 

I could be wrong but i belive the etec heads will support up to like .550 valve lift.. For the stock 350 displacment i wouldn't go with to big of a cam just because of the intake manifold... A pretty popular cam is just the lt4 production cam, the specs on that one are really similar to the specs of the cam crane recomends... I wouldn't really go much bigger than 220 on the duration just because of the intake manifold... With the lt4 production cam you should be able to run 1.6 rr if im correct on the supported lift of the etecs (i think the lift might be a little higher than .550 that it supports)... which im pretty sure i am. As for converting it to roller the engine is already hydraulic roller, the only part that isn't roller on the engine is the rockers, which you can change out. I use the crane 1.6 gold race myself.....all and all i would say the production cam would be a nice little upgrade from the stock cam

 

so if i were to get the LT4 cam 1.6 ratio roler rockers, with the E-tec 200 heads everything would work toegether and i wouldnt have any clearance issues, correct?

 

That is correct. E-Tec 200's support 0.600" lift. Since you will be buying rockers anyway, get non-self aligning narrow-body ones and use the guideplates that come with the heads. This will require hardened pushrods which can be had from Comp Cams. They also sell an adjustable pushrod that is a tool you can use to get the contact pattern of roller-to-valvestem perfectly dead-on. The correct length pushrods needed can be read from the tool. I strongly suggest picking one of those up, proper valvetrain geometry will get you the most lift with the least amount of work and make your stem seals last longest. Keep in mind that depending on the patterns of the cam you may need two different length pushrods to make it right - one for the intakes and one for exhausts. The correct adjustable pushrod tool is the one that covers the 7.120" ballpark.

With narrow-body 1.6:1 rockers (such as Crane Cams Gold) on E-Tec heads your stock rocker covers will fit on without modification of ANY kind.

Before you put the heads on you need to make a modification to your block. Get yourself a 1/4" NPT pipe tap and thread the extra hole in the block below the bottom passenger-side lower waterpump mounting bolt. You will find the water pump does not use this hole but the gasket mysteriosly knows about it. This hole must be plugged. The E-Tec heads open up that water passage.

If you have wild power in mind for the future seek out some Cometic head gaskets for Vortec - they work.

 

cool thanks for letting me know about that extra hole, i would have freaked if i had gotten everythgin back together and the block started spiiting out water where ir had never done before, lol

did you use any type of aftermarket intake manifold gastet to help prevent future leaks or did you use the factory gm stuff or a felpro set? also how is the "prone to leak" intake gasket handling the whipple pressures?

also james b. what kind of dyno numbers are you putting down, your exact setup is what i'm going for other then i dont want the factory bump stick in there

 

ohh one more question on the e-tec's on the .200 raised exhaust runner, did you have any issues wtih clearance or not wanting to bolt up?

 

The Felpro Intake manifold gaskets are just like the old shitty GM design - pure CRAP. The new GM ones have improvements in many ways:
1. radiused bead junctions to prevent rupture
2. thicker plastic to prevent cracking and deformation
3. elimination of unnecessary extra bends in water passage bead
4. elimination of stress fracture points in plastic around ports
5. MOST IMPORTANTLY - metal inserts to prevent crushing

See? GM really DOES learn! lol


I have no idea what kind of dyno numbers it makes really. I'm sure torque is vastly more than horsepower. I would say about 650ft/lbs torque at the crank. Maybe 525 at the rear wheels. I still have the stock Vortec intake manifold on and if you've ever seen into one you know why they run out of breath. I do run the improved poppet-less GM Multec-II injection in it. It idles smoother but it's not a performance upgrade, just a functional one.

I'll tell you right now, the key to getting power out of a Vortec SBC is fixing all the stuff that prevents it from spinning faster. Of course, that's pretty much everything. Heads and cam are a great place to start. Protect the accessories with a smaller crank pulley, programming, maybe a better manifold with true MPFI, etc. The stock bottom end is good for 5600RPM, but in stock form it WILL NOT breath past 5000. I have extra fuel going into mine but cannot rev more due to the fact I am already exceeding the supercharger's RPM redline by 10% shifting at only 5200...

 

Not one bit. They have conventional SBC exhaust ports, not D-shaped like LT4 or Vortec Fastburn heads.

 

i'm going to have to stick with the factory intake to for a while till i can afford the commander system, where can you get the multitec system at, and how much does cost(roughly).

 

It's a GM part, number 93441235. You can get it from GM Parts Direct. (Everyone always ends up asking m if that part number is for one injector or the entire assembly - it IS the entre assembly of 8.) With shipping you're looking at about $225.

Old poppet-style CPI on top, new Multec-II assembly below. The new assembly places the actual fuel injectors (small ones) directly over the ports without poppets: