RHS Vortec heads

[H-K]

Has anybody used or know anything about these "Vortec" heads from Racing Head Service (RHS)? I was thinking of throwing them on a '91 350 (pickup L05) w/TBI to replace the restrictive swirl-port heads that came on the motor. With these heads, they claim you don't need to change the intake manifold because it has bolt patterns for both the traditional intakes or vortec intakes. I thought the main problem with putting vortec heads on a non-vortec engine was not only the bolt angle/location, but that Vortec heads had a taller port. If this is the case and they had to change the port dimensions, could it impact the flow performance?

http://www.racingheadservice.com/Information/Technical/Heads/ChevyVortec-Heads.asp

http://chevy.off-road.com/chevy/article/articleDetail.jsp?id=303197

 

[BumpaD_Z28]

using a non vortec intake on the vorte style heads sort of negates the effects of the heads in the first place ...

I run GM vortecs and and an Edelbrock Performer RPM on a 388 CI Cheyy, but it's not in a 4x4 BUT it performes VERY well ...

~DaVe

 

[Tacoma]

How do you figure?

 

[H-K]

using a non vortec intake on the vorte style heads sort of negates the effects of the heads in the first place ... ~DaVe

Can you help me understand why that would be? Is it just because of the port opening/flange dimension differences or am I missing something? I thought the Vortecs were superior to earlier GM OEM designs because of their port/chamber geometry -- I thought they supposedly flowed a lot better, but didn't get the sense this was only because of a difference in the shape of the port opening itself. I guess if the dimensions were different enough to cause a flow/volume restriction or bottleneck, then I can see how that would negate it, but if either port opening shape is equally capable of efficiently flowing the same volume, then I'm probably missing the point. What am I missing?

Thanks for your help/input.

 

[BumpaD_Z28]

How do you figure?

the ports don't line up well and it also creates a "strange" angle in the intake flow from the intake, to the head port, to the valve ...

No worries if someone wants to do it though ...

"I" just know better / have experienced the differences, others results may vary, or be acceptable

 

[BumpaD_Z28]

Can you help me understand why that would be? Is it just because of the port opening/flange dimension differences or am I missing something? I thought the Vortecs were superior to earlier GM OEM designs because of their port/chamber geometry -- I thought they supposedly flowed a lot better, but didn't get the sense this was only because of a difference in the shape of the port opening itself. I guess if the dimensions were different enough to cause a flow/volume restriction or bottleneck, then I can see how that would negate it, but if either port opening shape is equally capable of efficiently flowing the same volume, then I'm probably missing the point. What am I missing?

Thanks for your help/input.

You are not missing much, it is just about the combination of parts that make up the intake track, the Vortecs are better because of the port/chamber geometry, but it is also about the angle of the flow TO the valve, years ago people used to raise the ports on old school double hump heads, now the Vortecs are cast that way ...

Oh and I am a HUGE fan of the value of the Vortec heads for the money, I don't think they can be beat (in a cast head $ for $) ...

~DaVe

 

[Tacoma]

the ports don't line up well and it also creates a "strange" angle in the intake flow from the intake, to the head port, to the valve ...

That's all I could come up with. What I just don't know at all is whether that difference totally negates the improved flow/efficiency/whatever of the heads themselves....

I am a big fan of at least gasket matching ports when possible.