Hand ported vortec heads

[Supercharged111]

I dont have access to a flow bench so its anyone's guess. Hopefully worth 20+cfm

I would hope so too, it's just that my impression of the Vortecs is similar to an article I read years ago where someone was experimenting port by port and finding excruciatingly minimal gains on a set of GT40P heads. It looks like you're doing some very tried and tried things to these heads.

 

[Vilanus]

I would hope so too, it's just that my impression of the Vortecs is similar to an article I read years ago where someone was experimenting port by port and finding excruciatingly minimal gains on a set of GT40P heads. It looks like you're doing some very tried and tried things to these heads

Yes i went conservative. I know that you cant do a whole lot to improve the intake especilally. I applied what i understood to be good.

 

[Vilanus]

That looks like you touched the floor of the exhaust port. Which, if I remember correctly, is a big no-no. The Vortec heads benefited from an LT1-like intake port, but didn't get the D-port shape on the exhaust side to combat reversion. SSR is one thing, hogging them out is another.

I squared up the bottom, nothing more. I know you need to leave a step for reversion. The short side radius was polished but the shape remains the same. Here's a wider angle.is that bad?

 

[motorheadmike]

I squared up the bottom, nothing more. I know you need to leave a step for reversion. The short side radius was polished but the shape remains the same. Here's a wider angle.is that bad?

Honestly, yes. You should have worked the SSR, and left the port floor raw. Nipping the corners off reduced any reversion characteristics that were present.

 

[fleming442]

Constructive turbulence?
Boundary layer?

 

[Vilanus]

Well im happy it, and thats what matters! Have you done any motorheadmike?

 

[motorheadmike]

Well im happy it, and thats what matters! Have you done any motorheadmike?

I've been known to abuse a die grinder in my day:

MONTE CARLO - "COPO" Monte Carlo SS - Turbosaurus Build (Swinging Dick Racing's c*ck got bent... she bounced a little too high & hard, & came down awkwardly)

Door hinges and Pop rivets. I love it !!

gbodyforum.com

MONTE CARLO - "COPO" Monte Carlo SS - Turbosaurus Build (Swinging Dick Racing's c*ck got bent... she bounced a little too high & hard, & came down awkwardly)

What's a stock 4.8 bottom end realistically live to? I know there was that one that was about a thousand but that was on a stand. I think most people draw the line at 600 wheel because of the rods unless the 4.8 is special with it's smaller stroke? I'd say 154mph is realistic now. And yes...

gbodyforum.com

That said I am on the fence right now...

 

[64nailhead]

It’s very difficult to tell what’s been accomplished without a flow bench imho.
The Vortec was the smoke and mirror moment for GM with head design. It oitflowed everything that preceeded from .100-.450 by a wheel barrel load. Porting them usually, repeat usually, hurts the low lift flow. That’s not the end of the world unless you have .450 lift cam with sub 205 duration. Installing a .520+ lift cam and <225 duration cam is where porting becomes favorable - imo.

 

[Vilanus]

Cam is [email protected] .512 lift 108lsa hyd roller. Heads currently on it where my first and prolly worst then these. Engine runs real good though

 

[64nailhead]

That said I am on the fence right now...

^^^ SMH ^^^ Nice to see Mike breakin in new members right.

Cam is [email protected] .512 lift 108lsa hyd roller. Heads currently on it where my first and prolly worst then these. Engine runs real good though

Less floor work (kinda a waste of time), but you didn't hurt them to run the 6000 that your cam wants to run. Don'twaster your time gasket matching, has the same kind of result as hogging out the floor unless you can carry the gasket dimension to the radius.