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-   -   Cam for a Vortec 355 (http://www.hotrodders.com/forum/cam-vortec-355-a-225027.html)

M.Rydell 10-15-2012 12:34 PM

Cam for a Vortec 355
 
Hello! This is my first post here.


I'm just woundering what cam will be the best for my engine. Car is Camaro 69 with a th350 with 3000 stall and 3,55 gears. Vortec heads 10:5.1 cr Air gap intake quickfuel 750 e85 headers
Xe274 or 12-672-4 cs nostalgia 30-30h+ or Isky 278 mega cam

thanks alot for the help!
Cheers from Sweden!

ap72 10-15-2012 12:45 PM

XE274 or SMALLER!!

the 268 works well with stock Vortec heads.

M.Rydell 10-15-2012 01:31 PM

Heads can handle up to .550 lift. Forgot to write that:)

ap72 10-15-2012 01:51 PM

Quote:

Originally Posted by M.Rydell (Post 1599371)
Heads can handle up to .550 lift. Forgot to write that:)

Then you need to step up to a roller cam if you want that much lift. You only need about 225/230 duration (on a hydraulic cam), and maybe 5 degrees or so less.

If you can't afford a roller cam you can run an aggressive solid flat tappet cam with higher ratio rockers, good springs, and grooved lifter bores and face oiling lifters and it MAY last.

For something like that try the Lunati 60140 and only run 1.6 rockers on the intake.

Running a roller cam will get you better performance and durability, but the costs are higher as I'm sure you know.

techinspector1 10-15-2012 02:26 PM

Here's a checklist that I wrote and that has been improved by other members. The intake closing point of the cam must be matched to the static compression ratio as you will learn by reading the tutorial from Crane that's shown here.....
http://www.crankshaftcoalition.com/w..._compatibility

cobalt327 10-15-2012 02:37 PM

Quote:

Originally Posted by M.Rydell (Post 1599371)
Heads can handle up to .550 lift. Forgot to write that:)

Are you talking about the ability of the springs to handle that much lift, or are you talking about the heads being ported to flow well at 0.550" lift? The stock ports are all done well before then. So adding lift past the point of max flow really won't get you more power, it would be the added duration that would help.

Added duration helps at a higher rpm, provided the port doesn't become so turbulent at higher rpm that the power is hurt instead of helped. But at the same time, increasing duration costs low end power, all else being equal. In a street driven vehicle, keeping a strong bottom end helps a lot more than peak power output. Look at it like this: you will see the lower rpm range every time you pull away from a stoplight. You may not see 5000 rpm a half a dozen times a day, if that, in ordinary driving.

The ideal cam would instantly open and close the valves. Obviously, that cannot be done w/the production valve train of a SBC. So the closer to instantaneous valve action you can get will give you more power under the curve. That's where the XE and Voodoo cam grinds come into play.

The XE cams have gotten a lot of bad press due to wiped out lobes and noise, but for the most part- as long as the cam is installed correctly and everything is checked carefully, they will not fail any more often than any other high performance flat tappet cam, and they will make good power. If I were going to run a flat tappet Comp cam, I'd seriously consider having it nitrided by Comp, anyway.;)

If at all possible, run a roller cam and matching springs.

Good luck.

ap72 10-15-2012 02:57 PM

Quote:

Originally Posted by techinspector1 (Post 1599385)
Here's a checklist that I wrote and that has been improved by other members. The intake closing point of the cam must be matched to the static compression ratio as you will learn by reading the tutorial from Crane that's shown here.....
http://www.crankshaftcoalition.com/w..._compatibility

I wouldn't worry about this link too much as it doesn't account for displacement, heads, intake, exhaust, application, carb, fuel, etc. Without considering those aspects its as useful as any advertisement or summit catalog (not much), I still can't figure out why it hasn't been deleted as its VERY misguiding.

Truth be told with E85 as your fuel you can run as small of a cam as you want, and your heads will go into choke right under 6,000rpm or so so there's no sense in camming for more than that unless you want your efficiency to go to hell. Assuming a good dual plane intake, headers, and exhaust, you'll want about 220-225 duration on the intake, and 225-230 duration on the exhaust for a hydraulic cam @.050".

As Cobalt mentioned stock heads peak out at a hair over .500" lift, going past that on stock ports and valve job won't gain you much (though it will pick up a little).

For a good street 350 stick with 1.94/1.5 valves but get a good valve job, open the throat to about 89-90% and open your runners up (finished volume around 190cc's with good even runner taper is a good target for Vortec heads). Those mods can pick up another 25+hp on a well built 350.

techinspector1 10-15-2012 03:24 PM

Quote:

Originally Posted by ap72 (Post 1599397)
I wouldn't worry about this link too much as it doesn't account for displacement, heads, intake, exhaust, application, carb, fuel, etc. Without considering those aspects its as useful as any advertisement or summit catalog (not much), I still can't figure out why it hasn't been deleted as its VERY misguiding.

Man, you are SOME piece of work! Read the introduction on the wiki article I linked, it explains that it's elementary.

It's beginning to come back to me why I was off this site for a while. I don't need the aggravation from a small person with a tiny little mind like you who has little or no clue. You have ZERO articles up on the wiki, but you have to rag on my stuff???????? :smash:

vinniekq2 10-15-2012 03:36 PM

for the cam choice? what is the application? Are you racing,if so,what kind? A roller cam is a good place to start. A hydraulic roller works well.Your heads are moderate and a small roller will make it a lot of fun to drive.

vinniekq2 10-15-2012 03:41 PM

also,? is there any porting on those vortec heads? especially the exhaust side???

cdminter59 10-15-2012 04:39 PM

Cam for a Vortec 355
 
Here are a few cams I would use if I had a Chevy 355. Howards Cams CL112591-08 - Howards Cams Hydraulic Flat Tappet Camshaft and Lifter Kits - Overview - SummitRacing.com Lunati 10120410LK - Lunati Bracket Master II Cam and Lifter Kits - Overview - SummitRacing.com Crane Cams 100072 - Crane Energizer Cam and Lifter Kits - Overview - SummitRacing.com A good friend of mine bought a 1969 Camaro with a 6 cyl back in the late 70's. Then he bought a 350 rebuildable core. He rebuilt the motor using all GM parts from our local Chevrolet dealer. When he finished he had a strong running 69 Camaro, 4 speed trans, 4.11:1 rear. The exterior color was Hugger Orange with a standard black interior.

vinniekq2 10-15-2012 05:34 PM

110245-12S NA 278 284 225 231 .500 .510 112 108 Hyd. Hyd. 1,2

something like this for a mild hydraulic roller and you would be very happy,I believe.

M.Rydell 10-16-2012 01:15 AM

I would like a hyd roller but The prize is too high in Sweden, about twice as much. So i like to keep it a hyd flat tappet for now. Car Will be a weekend warrior no daily driver.about 80% street and 20 strip. So i cant decide between those cam i listed.

Thanks alot all help I'm really grateful for the help!

ap72 10-16-2012 07:45 AM

Quote:

Originally Posted by M.Rydell (Post 1599550)
I would like a hyd roller but The prize is too high in Sweden, about twice as much. So i like to keep it a hyd flat tappet for now. Car Will be a weekend warrior no daily driver.about 80% street and 20 strip. So i cant decide between those cam i listed.

Thanks alot all help I'm really grateful for the help!

Of the cams you listed the xe274 is the best. If you insist on using that cam the Vortec heads would really bennefit from a good valve job and porting.

hpete 10-16-2012 10:19 AM

[QUOTE=ap72;1599602]Of the cams you listed the xe274 is the best. If you insist on using that cam the Vortec heads would really bennefit from a good valve job and porting.[
A good valve job that includes 2.05 intakes, 1.6 exhausts, swept chambers and enlarged bowls


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