Visit The Dirt Forum for More Information

Author Topic:   Vortec CC's
340duster
Member
posted November 20, 2003 11:00 AM
What is the combustion chamber size of a vortec head?
Also to redrill them to use a standard intake is this a difficult process, Should I build a jig?
What size valves do they come with as well? I have heard horror stories of two piece valves? What is up with these.
I have also heard that there is high lift clearance issues to the top of the valve guide is this true?
What size is the stem dia? 11/32"?


dirtbuster
Member
posted November 20, 2003 12:58 PM
chamber is 64cc
I dont think redrilling them would be tough..just use the right gasket to find the hole locations and then make sure you drill them at the right angle. If you can I would reccomend running an intake made for the Vortec otherwise the ports wont line up and it hurts the airflow poetentiial. Plus some intake manifolds wont actually cover and seal the entire port leading to air leaks.
They come with 1.94/1.50 valves stock, dont know about the 2 piece deal.
You cant run more than about .450 or so lift without having the guides machined down to allow more clearance with the retainer. I think if you run them without the stock seals you can gain a little but not much. Best bet is to have them cut down. Also springs will have to be changed. The single springs that are on there are designed for low rev pickup applications.


rico 08
Member
posted November 20, 2003 04:34 PM
I've seen a few redrilled vortec's and it's a toss up in my opinion,when you use the older intake you need to use a very thick intake gasket to try to raise the intake up to the new vortec port location,and it's not the greatest fit hence the less than stellar performance,maybe GM will cast a bowtie with the vortec bolt pattern someday.


Speedway65
Member
posted November 21, 2003 09:08 AM
the latest gm power manual has the specs for redrilling them for older intakes.We ran this for 2 yrs with no problems,but rico is correct you have to use a thicker gasket.If i remember correctly we used a Felpro,but im not sure what part #


340duster
Member
posted November 21, 2003 10:53 AM
Thanks for the info guys, what type of valve seal do they use, like the old SBC or the umbrella type like the mopars do?
Is it a quench type chamber?
The reason I am asking all these questions is one of my buddies wants me to help him build an engine for a sportsman car. (I have only built smallblock mopars for myself). The rules say no aftermarket heads, and I think the vortecs have alot of potential and may be one of the best stock oem heads available for the SBC.


340duster
Member
posted November 21, 2003 10:55 AM
Another question. Are the valves the same length and stem diameter as an older SBC?


boas51
Member
posted November 22, 2003 10:06 PM
THANKS GUYS!!, Now just need to find some castings!


dirtbuster
Member
posted November 25, 2003 02:41 PM
You can get complete assembled heads from some chevy dealers for around $250 ea with stock peices in them. Or some also have reworked vortecs with better valves, springs, and machine work done. for a little more.Check Scoggin Dickey parts in TX. Sometimes thse are better deals than locating used castings and working them yourself.


Sidebite252
Member
posted December 21, 2003 06:51 AM
Anyone ever angle mill any Vortec heads? More spacific - 909 castings?


stockcar5
Member
posted December 21, 2003 09:37 AM
i think your talking about a 906 casting?
i've seen them angle milled to 58cc. but i think you can go more.

luke

Mikey14
Member
posted December 21, 2003 06:14 PM
Pace has the heads already drilled and tapped for older intakes. They go for $259 each I think.

Spring pocket modified and rocker upgrade and you're done. Valves too if you are gonna go the full monte on the heads.

FYI.

trafficman
Member
posted January 25, 2004 04:23 PM
quote:
Originally posted by Mikey14:
Pace has the heads already drilled and tapped for older intakes. They go for $259 each I think.

Spring pocket modified and rocker upgrade and you're done. Valves too if you are gonna go the full monte on the heads.

FYI.


Mikey can you send me information on PACE so I can see about these ortecs aleady prepared for race with old itake. thanks-mark trafficman1313@charter.net



Back to the Archives