Vortec heads: believe the hype?!?

As I continue to hibernate here in Ohio I've had time to search the local craigslist, and one of the more interesting things are vortec heads. Just to confirm before I get myself into trouble, I can run those with my same 350 SBC headers? Do I really need to get a larger carb if I'm running a 650 edelbrock and their vortec manifold?

Think I'll get noticeably more power out of a 8.5:1 compression with mild cam?

For around $500 for the used assembled heads/intake it seems alright, and leaves some potential to build a 383 long block to put that on in the future.

Apologies for the rambling!

So do you think vortecs are worth fooling with after you figure in all the stuff you need and have to do to make them work? Or am I better off getting some aluminum heads and spending the extra money?

thanks!

 

buy a good set of dart heads if you have the money. if not I know there is something you have to do with the valve springs withthe vortecs because you cant get a whole lot of lift out of them?? someone on here will elaborate im sure.,

 

Thanks man yeah I understand you have to do some machining to use bigger springs or some such thing.

They seem to flow great but a lot of nickel and dime things.

 

It has been dyno proven that a nicely prepared (not even ported) set of vortecs will out perform basic aluminum heads. At 9.5 to 1, with about .510 lift, and decent duration, they can support 425 hp. Using a stock set, pin the studs, install the Comp Cams beehive springs abd have the guides cut down for whatever cam lift you want and go. Buy a set ready to run for $600. If you port them, leaave the intake side alone and do only a little to the exhaust and bowls.

 

I think the .510 lift is the problem?

Pretty sure the early standard vortecs have max .480 lift.

You can get them with more lift now from Pace Pontiac.

 

The Vortecs are definately worth it, been racing them for years in circle track. The stock springs are good to around .500 lift on a hydraulic cam but run into retainer clearance issues around .460-.470 lift. Stock springs are also only around 80-85lbs. on the seat, OK for a stock cam but you need around 110lbs. for a performance hydraulic cam. You'll also need dish pistons on a 383 shortblock, with flat tops on a 383 the Vortecs will give 10.8-11:1 compression, a little too much for the local horse-pee super unleaded.

The beehive spring mentioned above is a great idea too, the Comp #915 would be a good choice for a hydraulic flat tappet. But the spring pocket will have to be enlarged a little to fit, the stock spring is 1.250o.d. while the #915 is 1.290o.d.

You can also have your machine shop add the old-style SBC intake bolt pattern to the Vortecs so you don't have to buy a new intake. Fel-Pro gasket #1255 has both patterns stamped into it.

These are just a few things to keep in mind that might add to the cost of the Vortec swap, but in my opinion well worth it.

 

I'm really glad you mentioned that, in2hotrodz, I think I read that somewhere about re-drilling the intake bolt patterns and it just got lost in the cloud somewhere LOL

I actually found this edelbrock vortec intake for $100 local, I almost feel like I gotta snag it to pass on the deal to someone if I don't use it.

Wonder what a machine shop charges to drill a sbc bolt pattern?

So they really flow better than a basic aluminum head? I didn't realize that.

 

Not to hijack this thread, but I have a Vortec head question. I have one of the 350- 330hp crate engines in my car. It has the old style, 4 bolt valve covers. Do the Vortec heads only come with the center bolt covers?

 

I'm no expert but I've seen the center bolt valve covers listed as must haves for a vortec head swap, supposedly $30ish used

 

The true Vortec head was only available on trucks and vans from '96 to '99-2000 and has only center bolt style valve covers but you can still buy new complete castings from GM or places like Jegs or Summit for about $300-350 each. GM used the name 'Vortec' on their engines as early as the mid-eighties, so there is some confusion sometimes as to what a Vortec head actually is. The only true Vortecs have a casting number that ends in '062' or '906', anything else with centerbolt valve covers is just what's commonly called a throttle-body head.

By the way, our shop charges about $75 (I think, I'm not the pricing guy) to re-drill a pair of Vortecs for the old style bolt pattern. I think you'd be money ahead and just get a dedicated Vortec intake, the E-brock Performer RPM is probably the best all-around intake and you can find them used for about $125-150.

 

those heads used aren't worth much .
The dart or world ST torquer is a good head for lil over $600 complete new setup, it takes both valve cover styles ,some of the alum . heads have bothe intake bolt patterns drilled too.
why would you have to increase carb size ? you motor is still only 350cui.

 

Be careful if you try this...Factory Vortec heads might be different, but...
One of the reasons I bought a set of Racing Head Service "Pro Torquer" Vortec heads was because they had both intake bolt patterns. I figured that Id save a little money by using my existing Performer intake. Wrong! While the intake did physically bolt up, there was an 1/8" open gap between the top of my intake manifold and the roof of the intake port in the heads. The intake ports on these heads are about 1/4" taller than std ports. I tried 4 different intakes with no luck ...finally had to buy a Vortec intake.

 

This is exactly why hearing from guys that've been there and done that means alot. That could easily have been me trying to save a buck, cuz I'm a cheap bastard!

The reason I was asking about a larger carb is I read it in a magazine, of course! At least I think that's where I saw that. I have been playing with comp cams cam selector program , and you put in info and it gives you the theoretical engine output, and really between a 650 and 750 even on a 383 didn't make more than 5 peak hp difference the way.

That said, I don't know what I don't know, maybe it helps 5 other ways someone experienced can identify right off.

 

No you don't need a bigger carb. I run a 600 cfm on 350/330 hp engine,runs very good. Just plan on buying a vortec intake and valve covers.

 

I was taught this as rule of thumb for carbs...double the cubic inches for the maximun cfm on a carb. ie: 350 cu in X 2 = 700 CFM carb. I don't know how true this is but it has always worked for me. Even on built motors. A 350 is only going to flow only a given amount of air no matter how fast it spins. Anyways, that's what I've been told...thoughts?

 

Just remember that the Vortech heads are not drilled and do not have internal water pump bypass passage like the older small blocks. This is the bottom hole in the block under the lower water pump bolt on the right hand side. Without that bypass, you can have overheat issues. You simply need to run an external bypass like a big block on any small block using Vortec heads from the front of the intake near the thermostat to the water pump. Without it, there is not enough circulation of hot water passed the thermostat to make it operate correctly and the heads will get hot and the thermostat won't open soon enough.

Look at any stock Vortec engine and you will notice there is an external hose from the intake to the water pump. You need that external bypass on any engine you use Vortec heads and a thermostat.

 

Never had the issue Bad Banana speaks about but. Could be the heads they sell in the performance market have the water passages?

Any event, Pace Pontiac has brand new, "Vortec" heads, that are drilled "old style", and have the spring seats machine down so a .550 lift cam can be used.

Sadly, they have their web-site so jacked up right now that all I can find is a link to the bare head.

http://paceperformance.com/i-513527...rt-65cc-combustion-chamber-straight-plug.html

But they do have them complete. You'd have to call for more info.

This head is drilled for regular old valve covers and intake manifold.

Any old SBC exhaust manifolds will bolt right up to and of the vortec heads.

 

I've never had the bypass issue either. I am running a 1971 4 bolt block with a set of '99 Vortec truck heads. I built this motor in 2000 and used an Edelbrock Performer RPM manifold designed for the Vortec heads. I had the heads drilled for screw in studs and changed the valve springs to run a cam with .488 lift. I have been really happy with the power and the engine runs really cool.(I think the roller rockers help keep it cool because it seemed to drop water temp after the swap from non-roller rockers).

About the same time I did this Hot Rod and Car Craft did similar buildups. I think they made somewhere around 375 hp if I remember correctly.

 

That formula isn't very accurate. Remember a lot of 350's actully came from the factory with 2 barrel carbs,.. yes partly for economy BUT, GM knew better than to make a motor run lean,for most stock 350's this is actually plenty. Only the Hi-Po cars came with 4 barrels, and there is a reason for that, if you simply stuck a 4 barrel carb on top of a bone stock 350 that originally came with a 2 barrel, your actually going to run rich and hurt your performance, so how fast it spins indeed DOES make a difference.. why do you think the 302 Chevys that came in Z28 Camaros require almost 800 CFM? You put a 800 CFM on say your typical 302 SBF and you would run rich as hell, does that make sense now?

 

real world hype......spoken here from me. a vortec head swap from a 93 1.94 valve head gained literally 1 second on my model a..... went from a 13.30 pass last weekend of october , to a 12.34 pass the first weekend in november. motor is a 30 over dish piston , 93 truck motor with a 420/440 lift cam, 1.6 rockers, airgap intake, and a 750 holley. tame enough to drive everyday , even in the snow

they are a cheap alternative to aftermarket heads , if you have all the other stuff to go along with them (intake, rockers, covers,gaskets,etc) otherwise a pair of aftermarket vortec style heads would probably be cheaper, as most use the old style intake pattern and normal valve cover pattern.

forgot , they also gained about 7 hundredths in my 60'.... down to a 1.73 with 2.79 gears & 275/60 m/t's

 

The one thing you want to be careful of in a Vortec head is that used castings are frequently cracked. For what little it costs to get a brand new Vortec head, it's really not worth messing with used ones. That said, I should point out in the interest of full disclosure that I bought a set of heads for $100 last year, had 'em magged, and they're just dandy. They are sitting on my shelf waiting to be used for my stock car.

 

x2 on that one....a person i know had a pair redone , and ended up with more than what a pair of patriots or new vortecs would cost....

 

One of the reasons guys like these heads is that you can buy a new set over the counter from one of the GM performance dealers that will cut a deal for equal or less money than buying a used set and having a decent valve job done on them.
http://www.sallee-chevrolet.com/Cylinder_Heads/Vortec.cfm Plenty of info there

Jeggs has them for 299 each but that price can be beat I believe. They also want 620 for a single Dart head and while that may not be a big difference to some it is a lot of cash to me.

 

there are a few different styles of vortec heads out there, the later ones have a d-shaped exhaust port. both styles that I have seen have raised exhaust ports. your headers will bolt up, but you may be covering up some of the port. you do hafts machine the spring pocket & guides to run bigger springs, & must use the slef-aligning rockers. there are a few marine varieties also, or so I am told. all the ones that I have seen use the center bolts in the v/c. the chevy crate circletrack motor(p/n ends in 602) uses them, it makes 350hp/350+tq with a hyd cam, & dual plane manifold...the rest of the specs can be looked up on chevy's website.
I used the older vortecs on a street 350 with a mild hyd cam & a cheap egay chinese intake, low comp & made an honest 350hp/400 tq on the dyno.....
anybody know of a cheap vortec b&m blower manifold?
aren't chevy's fastburn ZZ4 heads just aluminum vortec's?

 

zz4 heads are corvette factory aluminum head. 6 bolt intake and center bolt valvecovers....

 

I think the amount of air a 350 flows has a lot to do with RPM, as previously stated. IMHO

 

I have a fast burn 385 engine that has vortec heads , and they're drilled to accept both style valve covers .

 

those are aluminum heads...correct?

 

I only know of two styles of Vortec heads: 1) Your standard light truck head with induction hardened exhaust seats with casting numbers '062' or '906', 2) A heavy duty truck head with inconel exhaust seats with the '906' casting number. Neither have a raised or D-shaped exhaust port. Regular SBC manifolds or headers bolt up just fine.

I know I havn't seen everything, but I see Vortec heads every day in the shop. You do have to be careful with used castings because they do crack, sometimes bad enough to split the deck wide open between the two center exhaust ports. But on the other hand I've seen more check out good then bad.

Just to give an idea what it'd cost to get a set done, think about this:
1) Used castings--$200, give or take
2) Full rebuild at SPM where I'd be the one building them--$250, this price includes tear down, thermal clean and shot blast, magnaflux, guides if needed (more than likely), valve grind, seats cut on a Serdi machining center, guide tops cut for PC-type seal, new valve stem seals, decks surfaced, full assembly, and vacuum check of all ports to verify valve seal. Any of your parts needing to be replaced would be an extra fee.
3) Optional: Cut for screw-in studs and guide plates--$125
4) Optional: Cut spring seats for larger o/d springs--$50

So that's $625 for everything, versus anywhere from $600-800 for a brand new set of casting from a parts dealer or warehouse. You also have to think about the expense of buying good ARP rocker studs and good guide plates (around $60 maybe) and a good set of valve springs (around $70-100 depending on what you go for). If you go with oversize springs or a double spring you also have to buy new retainers. Or just get a set of stock diameter performance springs and you don't have to get new retainers or have to pay for the spring seat machining.

It's not a cheap swap by any means, but a stock Vortec is so much better than a stock fuelie head I think it's worth it. Couple the heads with the right intake and you could be 40-60hp better than your old set-up without changing anything in the shortblock.

Sorry for the long post.....