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Chevy 350 with Vortec heads camshaft selection

 
Lone-Shark
V-6 Camaros rule!
Posts: 46
Joined: 10/09
Posted: 12/15/11 06:23 PM

Hey guys, I have a Chevy 350, 80's block, with new Vortec heads,steel head gaskets mid-grade piston rings, mid-grade flat-top pistons, TRW main and rod bearings, mid-grade crank, bored 60 over, everything is brand new, had it checked out and worked at the machine shop, new Edelbrock dual-plane aluminum intake, new rearend with 3.90 gears, Rochester 750 carburetor newly rebuilt, new 350 transmission with shift kit, (not the B & M ones, but actually had the transmission built to manually shift off of vaccuum), I currently have a Mellings MTC-1 RV cam, I would appreciate any tips or suggestions greatly, I'm trying to figure out what the best choices would be for a cam that will pull the most low-midrange power, or if they're any that have a power range all the way from low-topend, that works to, I think I should be able to pull some crazy power/torque from those 3.90 gears and the Vortec heads pretty easily.

P.S. - I'd like to get a Comp Cams product.  

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BuzzLOL
I have an SS396 tatoo
Posts: 380
Joined: 12/10
Posted: 12/21/11 04:19 PM

.. Looks like you already have a strong lowRPM/midRPM cam at 204/214 hydraulic flat tappet... about the only way to do better in that range would be to go to the GM ZZ4 208/221 hydraulic roller cam... if you can give up a little power below 2500 RPMs, you could go with the strong GM 'Hot Cam' 218/228 roller hydraulic cam...

.. Or similar sized Comp XE hydraulic flat cams or hydraulic roller cams... like Comp XE256 or XE262...  

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Lone-Shark
V-6 Camaros rule!
Posts: 46
Joined: 10/09
Posted: 12/22/11 10:04 AM

I've been told that the cam I have now is super weak, and everyone says that my car should have a lot more pull and power than what it currently does, I was wondering if upgrading the cam would make a big difference in my current set-up and pull out some power that's been hiding.  

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skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 12/22/11 03:47 PM

Hi there,
 For Hyd flat tappet cam I suggest the 222* // .447" GM Crane
 The 208* roller cam used in the ZZ4s can give the best of both worlds.
  All the best and Merry Xmas...  
skyeking

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 12/22/11 08:55 PM

Yeah if the cam specs posted about your cam in the other replies are accurate....its more or less a stock cam.

Very incredibly mild.

Id expect it to have snappy response right off idle...but to also go flat very very quickly.  Kinda like a dump truck motor....  heh.

The rest of your build can support more camshaft.  Id want to know more about what you do with this car before trying to make a call on a cam.  Also...whats the compression ratio?

You say you want low and midrange power.  Normally that equates to still having a small cam...but there are much better small cam options.  With your gearing though you dont need a tiny cam unless economy is very very important.

If a hydraulic roller cam is an option, this is by far the way Id go.

If not I personally prefer the lunati voodoo cams.  These were designed by the same guy that designed a lot of cams for comp cams back in the day.  the difference is that these are new and improved with an injection of modern technology.  they make better everything.  power, torque, vacuum, you name it.  

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Lone-Shark
V-6 Camaros rule!
Posts: 46
Joined: 10/09
Posted: 12/22/11 09:49 PM

Thanks to everyone for the input, @Buzz-I looked at those cams you recommended on the Comp site and they all look pretty good, decisions, decisions, decisions, haha.

@Skyeking- I'm going to check out your first recommendation, I'd prefer to keep it hydraulic flat tappet because I've heard roller set-ups are extremely expensive and can be a pain maintenance wise.

@Greg_moreira- I was just specifically saying low-midrange power because that's where most of all of the pick up races are either going to be won or lost and with the 3.90 gears and the 3-speed auto transmission I currently have, that doesn't leave too much of a window for topend, haha. I'm pretty sure my stall is one step above stock, as far as compression I've been told that it's most likely in the 10 range, right now my car want even do a burnout from a stand still, which I think something is seriously wrong with that picture, economy is definitely not important, this is my project/spring and summer driver, I just want to pull the maximum amount of all out horsepower, torque, and throttle response possible from this set-up, I was wondering if going with the biggest cam possible that this set-up will allow would put me where I'd like to be at, and if there's anything else that I could do with the ignition, intake or carburetor to pull even more ponies out of it? Basically I'm trying to bleed all of the potential out and figure out the best way of doing so.  

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 12/23/11 05:25 AM

Right on, now I follow you.  Considering that this is a fun driver....just a summer toy, I wouldnt be afraid at all to give it a little camshaft.  Nothing wicked, but something with some attitude.

With those heads and if you are around 10:1 compression, my hands down favorite pick for an off the shelf cam would be the lunati voodoo 268.

It will be worlds different than your current cam.  If you are dead set on comp....one of their extreme energy camshafts would be the closest offering they have.  the XE 268 or XE 274.

The 268 variety camshafts can get by with a stock, or mildly over stock converter, but would still do better with a good quality converter.  Avoid buying a cheapie converter.  The converter is one of the single most influential pieces concerning how much power you actually put to the tires.

Dont be afraid of a larger stall speed either.  With a good converter, many of them can be made tight enough that they drive very much like stock converter with normal amounts of throttle for driving....yet really stall up only under heavy throttle.

Id want a 10 inch converter that makes around 3000rpm of stall speed for any of these cams.  And I would not be looking at TCI or B$M.  For a good converter....PTC, TSI, Coan, ATI, and Edge are just a few.  350 bucks will get you into a good converter from most of these companies. 450 will get you something really good from any of them.  It WILL be better than something you can order up out of summit.  Call those guys(the converter company) and have them get you the right one.

FYI I drive around on a 9.5 inch 4000rpm stall speed.  Youd never ever know it was anywhere close to a 4000 stall if you went for a leisurley drive in my car.  It feels like a rather tight and mild converter.....til you step on the gas.  

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 12/23/11 05:36 AM

Just a couple more points I wanted to add(the last post was gettin long).  Concerning hydraulic roller....yes you are right it can be pricey.  Count on spending a grand at minimum in most cases.  I have north of 1300 in mine which only accounts for cam, lifters, valve springs/locks/retainers/locators, and pushrods.

The cam I bought was used.  Very low miles(nothin wrong with a used roller) but it was only 150 bucks...  bout half the price of a regular roller, so Id have about 1500 in it, not including rockers, or the timing set(you dont necessarily need those parts to convert to roller if you already have good stuff).  There is around another 400 to add to the total, so yeah....price adds up fast.

Reliability and maintenance is no concern.  With good parts...set valve lash once, glue the valve covers on and never touch it for tens of thousands of miles.  Just like a hydraulic flat tappet.

One other thing to make note of....but what, if anything has been done to your heads?  Vortec heads as is cannot handle a higher lift cam.  They need a little work to be able to do so, and with that in mind...you "may" be limited, and if you dont wanna pull the heads and have them worked for proper clearance with a higher lift cam...it makes us rethink things.

Lastly....lets get this motor you have running better than it is in the meantime.  For starters, unhook the vacuum advance, plug its port on the carb, and check the timing at idle and tell me what the initial/idle timing is.

Then...slooowly but progressively bring the rpm's up til the timing stops advancing and tell me how much total timing you have.  

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skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 12/23/11 02:51 PM

Laugh Hi People,
 I had a 204 cam in my 3..1/2 ton truck which was great.
  Downside was as far as peak power was concerned as you
 expected that the lights were on but nobody was home over
 4000 revs which nullified the use for a street car meant
 to go.Certainly not a Saturday Night Cruiser Mad  Shocked
  The motor ended up in a 2 wheel drive Toyota farm truck
 and is still going eons later...
  I have no access to all the info youse guys have but I have
  a hunch that there would be very little difference between
  many of the 222////224 cams Confused  Cool Skyeking...
   Merry Xmas to all inluding Peter//J;Man./Poncho man../a;69
  and never to be forgotten..Sky..Larrikin Blush  Cool  Grin  
skyeking

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 12/24/11 02:58 AM

I looked that cam up on mellings web-site. Thats what you have a RV cam and a torque cam. They say it runs out of steam at 5,000. So its not going to be a top end cam. Especially with 3:90 rear gears.

Look at Lunati's Cam P/N 60102. It's RPM range is 1,400 to 5,600. If you use Lunati's or Comp Cam use lunati's Micro-Trol lifters. This cam will work nice with the TH350 and 3:90 gears. Grin  Cool  

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