Max Lift with Vortec Heads - Lateral-g Forums

street3285 · #1 06-30-2010, 10:47 PM

I recently bought some vortec heads for the small block I am going to build. I have always read that the max lift is .480" with the stock valve springs. Is this true? Or is this only if running a roller cam. I am going to be using a hydraulic flat tappet.

ElkyZO6 · #2 07-01-2010, 07:06 AM

That is correct for stock springs. They are a smaller diameter spring too. Beehive springs or machine the heads for regular ones are your only option.

street3285 · #3 07-01-2010, 08:14 AM

Is that the max using a roller cam? Or can I get away with a .500" lift cam since I am going to a hyd. flat tappet?

ElkyZO6 · #4 07-01-2010, 09:10 AM

I'm not sure, but I would change them to be safe.

street3285 · #5 07-01-2010, 09:29 AM

It is close, but do you think I will be able to get away using this cam with the stock springs?

http://www.compcams.com/Cam_Specs/Ca...?csid=108&sb=2

What is the deal with shimming the valve springs? Or is that just not the right way to do things?

ElkyZO6 · #6 07-01-2010, 11:29 AM

The stock springs won't be able to control the valve at those rpm's aka valve float. Read this on shimming the springs. http://www.supercarsunlimited.com/in...gs/springs.htm

If I was you I would run these springs. http://www.compperformancegroupstore...e=SBCNEWValves

What rocker arms are you going to use?
I'm running the same heads on my El Camino, but with a smaller cam so I've been down this road before.