Vortec heads: believe the hype?!?

Isn't the heater core and hose essentially a bypass from intake to waterpump?

 

Doesn't the heater have to be "ON" at start-up for this to occur?

 

I've got a friend with an off-topic Nova Bracket car that ran low-9's with a nicely prepared BBC....until someone offered him some nice money for the motor which left him needing an engine. He had some Small Block stuff laying around so he threw together a 383 SBC with a solid roller cam and a set of late-Nineties Pick-up truck Vortec heads prepared very mildly. Now, this car was prepared nicely and was slightly under 3000 LBS. with a pretty loose race Convertor and 14 x 32 rear slicks but get this........the car ran 10.20-.30's and surprised the heck out of him and me!

 

In the mid 60's chevy had a service bullitin"sp" that informed us to block off the block hole under the water pump if your engine was overheating at low rpm's.Summit sell thermostats with the bypass holes in it.Zips water pump riser do not have the bypass in them.Jimmie King

 

Almost everything you have learned in the last 50 years will not help you with these heads. trust me I am from the same class of gear heads as your father. Vortec head are totally different. I think there totally opposite to early heads.

 

I didn't read this whole thread so bear with me!

I think over on nastyz28, there is arguably the world's best sticky on Vortec's and for lift hunt up Dirt Reynold's "Ghetto Grind".

pdq67

 

I run the vortec heads. Edelbrock 600 cfm carb. Smallest comp cams thumpr cam. Idles a little rough(awesome)and pulls hard from idle to 5800. These heads make great torque. Perfect for the street. I got two more sets under the bench, not for sale.

 

http://www.nastyz28.com/forum/showthread.php?t=56505

 

I should I did the same.I had two sets two but sold both.wrong move.

 

I guess that trumps 60 years of GM engineering and development...

Sorry to ruffle your feathers. Just sharing for those that lack your war chest.

 

To Quote Gary Penn formerly of GMPP from the Nastyz28 thread which is a very detailed

"Regarding porting, a little clean-up on the vortecs is OK, but if you dramatically open up the ports you lose the venturi effect in the intakes that makes them flow and perform as well as they do. The vortec head was designed by the same guys that did the LT1 and LT4, one of which was a former GM winston cup head engineer for over 10 years, he's back at GM Racing doing race heads again. There is no head for a 23 degree smallblock which is more technologically advanced in terms of flow management and combustion management than the vortec. Have a great day and by the way we invented the small block, who do you think knows it better than us?"

 

I thought it'd be good to bring this thread back to life, as the Vortec head still continues to be a frontrunner with regards to budget sbc engine builds.
My story with Vortecs goes way back to when they were first introduced into the GM trucks. A friend, working at a local GM dealership let me know that an engine with these heads was about to be released from audit, from a truck that had an engine breakage. I was able to acquire them, and we installed them into my then fresh 406 equipped '66 Nova. With 3.08 equipped gears, the .480 lift Comps spring equipped little wonder would card easy 12.50's all day long . A bit of time later, I was approached to run the then newly released GM "Bowtie" Vortecs, through GM Racing, and Chevy High Perfomance. I had the GREAT Opportunity to converse many times with GM Racings Robert Cross, who at the time was project manager for the Vortec program. He constantly bestowed the attributes of the Vortec head, and he was right on all counts. Out of the box, the best flowing production head GM made. We've since lost Bob Cross, but I feel he was a very instrumental part of why we have these great cylinder heads. Many manufactures try to copy the basic designs of this head. It should go to reason that they are a pretty good performance piece.

This story should give credence to how effective the heads really are, even when pitted against a cylinder head higher notches on the flow ladder.

http://www.chevyhiperformance.com/techarticles/0610ch_gmpp_cylinder_head/index.html

 

FWIW I ended up getting a used set of Vortecs complete with rocker arms cheap enough that if they turn out to be cracked they're worth it for just the parts.

I got a used air gap, a 600 cfm Holley, and some center bolt valve covers so I think I'm good to go.

I'd like a bigger carb, but that'll have to wait till I find one I can afford.

Can anyone suggest a cam to go with it that'll let me run power brakes? I'll have around 10:1 compression with the cast rotating assembly that's low mileage.

I've got a 3.0 rear end and rarely go over 3500 RPM, so I figured any mild street grind that gives power from 1000 rpm+ is probably a good choice, but other than staying away from too high of lift for these heads I don't know squat about cam selection.

 

Were you able to read the story in the link I posted? Check the cam...... Its based on a Lunati grind.

Here's another story, vaguely familiar to my old build:

http://www.chevyhiperformance.com/techarticles/148_0306_chevrolet_406_big_block_torque/index.html

I'm sitting on a complete Vortec top end. A set of new ones, GMPP intake roller rockers, centerbolt valve covers that I am going to once again ask great things out of. But this time, the bottom end is a 410 smallblock, with Mahle pistons, and a bit more compression. It'll be a bit of a different cam grind to accentuate the torque output of this combination, but still be friendly with regards to bleeding off of cylinder pressure. But still the same 'ol set of Vortecs......

 

Thanks teddisnoke, I did read the article!

I liked your story a lot as well.

Do you think that cam would apply to my 350 with a stock bottom end? It's a 406 in what appears to be more of a drag car, I think I need more power down low.

I'm going to read the other article now

edit: that is one mean 406! 525 # feet at 3500?!?

 

If you are speaking of my car, it was far from being a dedicated drag car. We drove it all over the West Coast, including some looong sections of a cetain 'powertour'. It was very deceptive. But, if you think the cam may be too much, Comp Cams has a very good line of cams , the "Extreme Energy Series":

http://www.compcams.com/v002/Conten...Title=XE262H-10&AspxAutoDetectCookieSupport=1

http://www.compcams.com/v002/Pages/386/XE256H-10.aspx

http://www.compcams.com/v002/Pages/388/XE268H-10.aspx

The Comp XE 268 was and still is a great cam. I ran it for a number of years in a small block 350. The 262 would give you more vacuum, and be a bit more tame, without sacrificing driveability at all. Our small blocks do not need too much to have a good time and still last !

Here's another one on the Nova. I think when I had it, and ran it so much, being a daily driver, and racing it, that it had people starting to realize you can do quite a bit with some very basic, dependable components. Try to not "overthink" your combination.


http://www.maxchevy.com/features/2008/iii_1-snoke-1.html

 

Ohhh so thats YOUR Nova! I didn't know. Low 12s is pretty stout for a driveable street car.

That car looks like it should in no way do 12 teens.

Why did you decide to keep the cast crank in it?

Thank you for your time, I didn't realize you built that car.

Not half bad for an amateur! ;-)


EDIT: The cam suggestions and the links are much appreciated! I've been so into the camquest software I don't know if I ever saw those dyno results before. I feel like I'm headed in the right direction now.

According to the desktop dyno, the larger cam makes an extra 15 hp average and 10# of torque average, vs the XE256.

That seems pretty noticeable to me, and maybe outweighs the fact that it moves the power range up a little more in the RPMS?

I wonder in real life how the true street driving experience would differ.

I can read all the descriptions and books that I want, but nothing speaks like experience.

 

Anybody know anything about these Summit Vortec's?
http://www.summitracing.com/parts/SUM-151124/

Who makes them? How close to GM's Vortec's are they? How well do they work? Is there a better value out there in a new Vortec head?

 

I have a pair on a motor Ihave and was going to take em off .I read on another site that the vortec cast iron heads that I have were not very good do you all have some casting numbers for good heads?

 

There is no single best cam for any engine. Contact your favorite cam grinder tech line and discuss the parameters of your particular build and the use of your engine. (street, strip, cruise, towing, etc) They will recommend the optimum grind.

 

The EQ heads on ebay are cheap and well rated