someone on this board just said they stated making vortec heads with "old school" bolt patteren.....

 

that would definately be awesome. Can anyone verify this?

Eric

 

One of the dealers that advertises in the national magazines is offering Vortec heads drilled so a "normal" intake will bolt to them.

The ports still don't match, though.

 

yeah i knew about the drilling....I would love it if they made heads with the right bolt pattern and port alignment.....

 

Yep,
I looked into these heads after someone on one of these boards said something. Looks like us tpi guys are gonna still have to pay $300 for an intake

 

"Vortec" = raised intake port

Therefore, by its definition, no such thing as Vortec heads that fit old intakes.

 

The vortec intake for the carbs is only about 50 bucks more than, a standard intake, it's not a big deal, to make the ports lineup. That's a small price to pay as i see it.

The only other oddity with those heads is that if your running a flat tappet hydraulic cam, you need self aligning rocker arms. Most of them cost the same self aligning or non self aligning,, if not the same the difference is generally less than 10 dollars.

 

I guess my queston is when it comes to tuned ports... how much is a high flow base, then how much is the new SD vortec base...

 

The kind of cam you use has nothing to do with what kind of rockers you need to run.

However, SA rockers are correct AFAIK, but for other reasons; those heads come with pull-out studs and large push rod clearance holes, so neither guide plates nor the slot method of rocker alignment is available with them. The only method left is SA rockers.

 

To keep everyone happy, I will try to clarify as much as possible. Vortec heads flow real well at, .500" lift compared to other "replacement truck heads, or factory replacement heads, or factory castings." If a cam was going to be used that incorporated at least .500" lift, I would strongly suggest using screw in studs. If you get these heads machined for screw in studs, you could get guidplates at the same time, and not have to worry about SA rockers. As far as port alignment, the fact that these heads flow well compared to other "factory truck parts, factory castings, or factory replacement heads," is partially attributed to the ports being taller. I can not remember the guys name, but on the message forum at Pace Parts, a gentleman put a standard TPI base on a set of Vortecs, but had to use 3 intake gaskets per side to get the ports to somewhat line up.
Ponykiller,
As far as the cost difference in bases, an Edelbrock base is $360, SD base is $400.

 

Chevy High Performance just flowbenched a bunch of small block heads and recommended using the .300 lift numbers for evaluating a good performance head. They found the Vortec to be by far the best value on the market, bar none.

From what I understand, it is the roof of the intake port that is the culprit, being 1/10 inch higher than the manifold's port.

Doesn't that sound like something easily remedied with a die grinder? I mean like, what is a tenth of an inch to smooth out and open up on an aluminum intake?

Sounds like peanuts to me. Anybody done this?

 

Moved the whole port. Most manifolds don't have enough meat to grind up to the roof and still seal the gasket, and you've still got the floor mismatch anyway.

 

That's kinda what i was getting at RB. A factory gm hydraulic roller setup had built in guidplates, which make self aligning rocker's unnecessary.

The vortec heads are built assuming those will be used and used round holes instead of slots,

when you run a flat tappet cam, you generally have no guidplate, and with no slot in the heads, the SA rockers are now a necesity.

Another point there, the vortecs flow well at .5-.52 of lift but they are better than nearly every other head from .2-.5 where the vavle spends most of it's time.

As far as the screw in studs. If your running a standard hydraulic cam with 1.5 rockers and keeping it to .5 lift there's really no need to replace the studs if everything is set up properly.

that Higth with the strength of the springs for a roller cam however may be a problem with pulling them.


Sitting Bull, i guess my point is.. this, if' you've spend the money to put a strong running motor together, why try to mangle an intake, when the propper one's only another 40 bucks and witll perform much better.

 

The enormous majority of roller motors (L03 & cast-iron L98 for example) don't have guide plates. The heads do not care what the topology of the lifter is. Guide plates have to do with making sure the rocker stays on the valve, and have nothing to do with what's going on down inside the block.

Those of us who have been building roller motors for all the decades that they've existed before the factories hipped up to the idea have usually used guide plates. But, we've also been using them on flat tappet motors intended for any kind of performance usage too. They're the standard head prep for any motor with more than a stock cam, but less than a Jesel or similar shaft rocker system.

You can put guide plates on a set of heads and run either roller or flat tappets; or use the slots in cast-iron heads with either kind; or use self-aligning rockers with either kind. Again, the lifter topology does not affect the choice of a system for guiding the rocker on the valve stem tip.

The trick to getting value out of the Vortec heads is to avoid doing machine work to them to overcome their limitations, and instead, design your combination to get the most out of their built-in advantages. They are excellent heads out of the box, compared to other factory heads out of the box; but they are nowhere near as good as a decent set of aftermarket heads, and they're cast iron besides. Their strong point is their combination of low price and good flow. But, once you get into machining on them, you can rapidly run up such a huge bill in machine work that you will exceed the cost of a superior set of aftermarket heads. So it doesn't make a whole lot of sense to spend money on machining them to get rid of the pull-out studs and replace them with screw-in ones (required for guide plates).

Better springs than what comes on those heads are needed for any kind of performance cam. The stock springs are intended for replacement truck applications (that being what the heads are designed for) and are not appropriate for hi-perf use of any kind. But, in keeping with the general concept of avoiding machine work on the heads, use a good-quality stock-diameter spring such as Comp or Crane or Lunati or one of the other major mfrs' entry-level spring, and a cam & rocker combo (flat or roller, it doesn't matter) with under .480" of valve lift, with SA rockers, and you'll have what you need.

 

My thought was that many people already have an aluminum intake and would like to reuse it, instead of having to spring for an all new Vortec type.