Vortec heads: believe the hype?!?

That link doesn't say anything about raised or D-shaped exhaust ports, I'm 99.9% certain they are the exact same head as sold on the truck motors and over the parts counter. The only D-shaped exhaust I know of came out on the Corvette aluminum L98 and LT-1 heads and on some of the new ZZ-style crate motors that had aluminum heads.

I've been racing the Vortec heads for many years in different cars and classes with several different header configurations and have never had any problems with ports not matching up or having to buy special headers or gaskets. But I said before, I've seen a lot of things, but not everything.

I had good luck with my heads, I guess. One set had stock factory valves, stock press-in rocker studs, stock diameter valve springs to match a 256/264dur @ .050 solid lifter cam and I turned the motor 72-7300 all the time. Made for a pretty potent combo with a 750H.P. Holley and an E-brock RPM intake on a pretty light rotating assembly.

I'm not going to say what other people have or don't have, I'm just telling about what I've seen myself.

 

ok, maybe this will give a better picture of what I have been trying to explain (gasket 12a):
http://www.schoenfeldheaders.com/sbflanges.htm
these matched the ports on my '602' heads nicely......
I posted the chevy link, cuz i thought that they were calling them vortec heads.
hendren race engines(among others) services these sealed crate motors & could speak to their durability. I have heard that it isn't usually cost effective to rebuild them, so if they do not crack like the street ones do they may be a good pricepoint.
jus sayin......

 

I get ya. We use a Fel-Pro gasket that's square port and they fit the Vortecs fine too. I think those you pointed out are really designed for the 604 crate with the 'fastburn' aluminum heads. Just a little FYI, Schoenfeld Headers is only about a 15 minute drive from my house, pretty convenient when you need a header in a hurry.

 

Some of you guys with the cracking issues may be causing it yourselves.

This is from Edelbrock's website and Votec manifold instruction sheet. What it fails to mention is WHY you need the bypass. That the hole from the front of the block under the water pump is routed to the deck surface. The Votrec heads do NOT have that hole drilled in them so the water does not bypass between the Vortec head and the block.


[FONT=Arial,Bold][FONT=Arial,Bold]SPECIAL NOTE: [/FONT][/FONT]

This intake manifold is primarily intended for use with Vortec heads on pre-Vortec blocks. Standard​

engine blocks route thermostat bypass water from the block directly to the water pump through the passenger side​

water pump mounting flange. ​

[FONT=Arial,Bold][FONT=Arial,Bold]If the manifold is used on a 1996 and later Vortec engine that does not have the[/FONT][/FONT]​

[FONT=Arial,Bold][FONT=Arial,Bold]in-block bypass passage, you must route a thermostat bypass hose from the water bypass port on the front of[/FONT][/FONT]​

[FONT=Arial,Bold][FONT=Arial,Bold]the manifold to the 5/8” hose nipple on the passenger side of the Vortec water pump. [/FONT]​

[/FONT]

Use a 3/8” pipe to 5/8”​

hose nipple fitting, and a 7” length of 5/8” hose to accomplish this. If your engine block has the thermostat bypass​

passage, use the 3/8” NPT plug supplied in the kit to plug the bypass port in the front of the intake manifold.​

The link is here.​

http://www.edelbrock.com/automotive_new/misc/tech_center/install/7000/71116.pdf​

Here is an even better link that shows the bypass hole in the block as well as more explaination as to why you need it.​

http://www.camaroperformers.com/cam...ro-vortec-heads-install/install-pictures.html​

Just sayin'... Nobody is forcing anyone to run the bypass and if guys are getting away with it, then I guess I am full if crap. I'm just sayin' I would .. Obviously, anyone can build their engine any way they want. ​

 

Thanks bud!

I'm slowly but surely getting my parts together.

I did a search online for how to hook up the heater and everything and just got more corn-fused!

I think I'll have to call their tech support on this one.

Thanks for the heads up. Good lookin' out!

My daddy taught me good, so right now I'm backin' up!

 

I did some research and went with the EQ (Engine Quest) Vortec iron heads that have the perimeter valve cover bolt holes. My RPM Air-Gap and headers bolted right up to them.

Click here: EQ Cylinder Heads - EngineQuest (EQ) | AAEQ - Manufacturers and Recyclers

I had Hamber (Rogers Performance) in Hatboro, PA assemble them for me and I couldn't be happier with Mike's work!

 

The aluminum head that has the vortec chamber and raised D shape exhaust ports is GM part #10128374. the 062 and 906 do not have D exhaust ports whether they are circle track 602 engines or not.

The Eq heads i did for Unk are a vortec chamber head but have the older valve cover bolt holes and the old style intake bolt pattern they are not re-drills they are made this way.

They will flow 244 on the intake at @.600 lift and 164 @ .600 on the exhaust side.

The stock vortec's if you are going to use them crack in the exhaust seats and i have seen the decks cracked also. Guide clearance on stock vortec's if using cast iron guides need to be .0025 for exhaust and .002 for intake. i did a lot of guide work for the local Dealers because of valve sticking in the guides and found that this is the min guide clearance for the factory heads.As far as the by pass hole for the water pump that is there for if the thermostat gets stuck we block this off in all race engines we do with no over heating problems vortec and non vortec engines. If it was A cause for a cooling problem then why is this done on only one side of the block and not both.

 

Hey Mike I like what I see about those heads.

500 HP for $2500 article

CC220BA
220 cc intake runner / 64 cc combustion chamber

<table style="border-collapse: collapse; table-layout: fixed;" width="575" align="center" border="0" cellpadding="0" cellspacing="0"><colgroup> <col width="55" span="3"><col width="73"> <col width="55" span="2"> </colgroup> <tbody><tr height="13"> <td class="xl24" width="55" align="center" height="13"> Intake </td> <td class="xl25" width="55" align="center"> Lift </td> <td class="xl25" width="55" align="center"> CFM </td> <td class="xl24" width="73" align="center"> Exhaust </td> <td class="xl25" width="55" align="center"> Lift </td> <td class="xl25" width="55" align="center"> CFM </td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.1</td> <td class="xl27" width="55" align="center"> 71.5</td> <td class="xl28" width="73" align="center">

W/O pipe ​

</td> <td class="xl27" width="55" align="center"> 0.1</td> <td class="xl27" width="55" align="center"> 64.1</td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.2</td> <td class="xl27" width="55" align="center"> 141.3</td> <td class="xl26" width="73" align="center"> </td> <td class="xl27" width="55" align="center"> 0.2</td> <td class="xl27" width="55" align="center"> 115.4</td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.3</td> <td class="xl27" width="55" align="center"> 196.1</td> <td class="xl26" width="73" align="center"> </td> <td class="xl27" width="55" align="center"> 0.3</td> <td class="xl27" width="55" align="center"> 145.1</td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.4</td> <td class="xl27" width="55" align="center"> 238.1</td> <td class="xl26" width="73" align="center"> </td> <td class="xl27" width="55" align="center"> 0.4</td> <td class="xl27" width="55" align="center"> 169.8</td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.5</td> <td class="xl27" width="55" align="center"> 265.1</td> <td class="xl26" width="73" align="center"> </td> <td class="xl27" width="55" align="center"> 0.5</td> <td class="xl27" width="55" align="center"> 189.3</td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.6</td> <td class="xl27" width="55" align="center"> 280.5</td> <td class="xl26" width="73" align="center"> </td> <td class="xl27" width="55" align="center"> 0.6</td> <td class="xl27" width="55" align="center"> 201.7</td> </tr> <tr height="13"> <td class="xl26" width="55" align="center" height="13"> </td> <td class="xl27" width="55" align="center"> 0.7</td> <td class="xl27" width="55" align="center"> 284.2</td> <td class="xl26" width="73" align="center"> </td> <td class="xl27" width="55" align="center"> 0.7</td> <td class="xl27" width="55" align="center"> 207.6</td></tr></tbody></table>

<table width="365" align="center" border="0" cellpadding="0" cellspacing="0" height="623"><tbody><tr height="13"><td colspan="5" class="xl24small" width="365" height="16"> Run on GM "ZZ4 Short Block</td> </tr> <tr height="13"> <td colspan="5" class="xl24small" width="365" height="16"> Cam .474" / .510" lift</td> </tr> <tr height="13"> <td colspan="5" class="xl24small" width="365" height="16"> Carb. 750 Holly</td> </tr> <tr height="13"> <td colspan="5" class="xl24small" width="365" height="16"> head part number run CC220BA

</td> </tr> <tr height="30"> <td class="xl24" width="73" align="center" height="31"> RPM</td> <td class="xl24" width="73" align="center" height="31"> EQ Torque</td> <td class="xl24" width="73" align="center" height="31"> EQ Power</td> <td class="xl24" width="73" align="center" height="31"> PTL Torque</td> <td class="xl24" width="73" align="center" height="31"> PTL Power</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 2900</td> <td class="xl25" width="73" align="center" height="16"> 337.0</td> <td class="xl25" width="73" align="center" height="16"> 186.4</td> <td class="xl25" width="73" align="center" height="16"> 334.1</td> <td class="xl25" width="73" align="center" height="16"> 184.4</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3000</td> <td class="xl25" width="73" align="center" height="16"> 341.4</td> <td class="xl25" width="73" align="center" height="16"> 195.1</td> <td class="xl25" width="73" align="center" height="16"> 343.3</td> <td class="xl25" width="73" align="center" height="16"> 196.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3100</td> <td class="xl25" width="73" align="center" height="16"> 352.2</td> <td class="xl25" width="73" align="center" height="16"> 207.9</td> <td class="xl25" width="73" align="center" height="16"> 355.4</td> <td class="xl25" width="73" align="center" height="16"> 209.8</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3200</td> <td class="xl25" width="73" align="center" height="16"> 363.9</td> <td class="xl25" width="73" align="center" height="16"> 221.8</td> <td class="xl25" width="73" align="center" height="16"> 367.3</td> <td class="xl25" width="73" align="center" height="16"> 223.7</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3300</td> <td class="xl25" width="73" align="center" height="16"> 365.7</td> <td class="xl25" width="73" align="center" height="16"> 229.7</td> <td class="xl25" width="73" align="center" height="16"> 362.8</td> <td class="xl25" width="73" align="center" height="16"> 227.9</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3400</td> <td class="xl25" width="73" align="center" height="16"> 364.6</td> <td class="xl25" width="73" align="center" height="16"> 236.0</td> <td class="xl25" width="73" align="center" height="16"> 363.9</td> <td class="xl25" width="73" align="center" height="16"> 235.6</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3500</td> <td class="xl25" width="73" align="center" height="16"> 367.4</td> <td class="xl25" width="73" align="center" height="16"> 244.9</td> <td class="xl25" width="73" align="center" height="16"> 365.8</td> <td class="xl25" width="73" align="center" height="16"> 243.7</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3600</td> <td class="xl25" width="73" align="center" height="16"> 372.7</td> <td class="xl25" width="73" align="center" height="16"> 255.5</td> <td class="xl25" width="73" align="center" height="16"> 368.8</td> <td class="xl25" width="73" align="center" height="16"> 252.8</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3700</td> <td class="xl25" width="73" align="center" height="16"> 376.5</td> <td class="xl25" width="73" align="center" height="16"> 265.2</td> <td class="xl25" width="73" align="center" height="16"> 376.6</td> <td class="xl25" width="73" align="center" height="16"> 265.3</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3800</td> <td class="xl25" width="73" align="center" height="16"> 375.2</td> <td class="xl25" width="73" align="center" height="16"> 271.4</td> <td class="xl25" width="73" align="center" height="16"> 374.6</td> <td class="xl25" width="73" align="center" height="16"> 271.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 3900</td> <td class="xl25" width="73" align="center" height="16"> 377.9</td> <td class="xl25" width="73" align="center" height="16"> 280.7</td> <td class="xl25" width="73" align="center" height="16"> 375.5</td> <td class="xl25" width="73" align="center" height="16"> 278.8</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4000</td> <td class="xl25" width="73" align="center" height="16"> 381.4</td> <td class="xl25" width="73" align="center" height="16"> 290.4</td> <td class="xl25" width="73" align="center" height="16"> 380.8</td> <td class="xl25" width="73" align="center" height="16"> 290.0</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4100</td> <td class="xl25" width="73" align="center" height="16"> 378.4</td> <td class="xl25" width="73" align="center" height="16"> 295.4</td> <td class="xl25" width="73" align="center" height="16"> 378.5</td> <td class="xl25" width="73" align="center" height="16"> 295.5</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4200</td> <td class="xl25" width="73" align="center" height="16"> 380.3</td> <td class="xl25" width="73" align="center" height="16"> 304.1</td> <td class="xl25" width="73" align="center" height="16"> 378.1</td> <td class="xl25" width="73" align="center" height="16"> 302.3</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4300</td> <td class="xl25" width="73" align="center" height="16"> 375.6</td> <td class="xl25" width="73" align="center" height="16"> 307.5</td> <td class="xl25" width="73" align="center" height="16"> 376.3</td> <td class="xl25" width="73" align="center" height="16"> 308.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4400</td> <td class="xl25" width="73" align="center" height="16"> 377.0</td> <td class="xl25" width="73" align="center" height="16"> 315.8</td> <td class="xl25" width="73" align="center" height="16"> 376.6</td> <td class="xl25" width="73" align="center" height="16"> 315.5</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4500</td> <td class="xl25" width="73" align="center" height="16"> 381.7</td> <td class="xl25" width="73" align="center" height="16"> 327.1</td> <td class="xl25" width="73" align="center" height="16"> 378.2</td> <td class="xl25" width="73" align="center" height="16"> 324.0</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4600</td> <td class="xl25" width="73" align="center" height="16"> 379.2</td> <td class="xl25" width="73" align="center" height="16"> 332.1</td> <td class="xl25" width="73" align="center" height="16"> 378.9</td> <td class="xl25" width="73" align="center" height="16"> 331.9</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4700</td> <td class="xl25" width="73" align="center" height="16"> 382.8</td> <td class="xl25" width="73" align="center" height="16"> 342.5</td> <td class="xl25" width="73" align="center" height="16"> 380.0</td> <td class="xl25" width="73" align="center" height="16"> 340.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4800</td> <td class="xl25" width="73" align="center" height="16"> 381.9</td> <td class="xl25" width="73" align="center" height="16"> 349.0</td> <td class="xl25" width="73" align="center" height="16"> 379.1</td> <td class="xl25" width="73" align="center" height="16"> 346.4</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 4900</td> <td class="xl25" width="73" align="center" height="16"> 379.3</td> <td class="xl25" width="73" align="center" height="16"> 353.9</td> <td class="xl25" width="73" align="center" height="16"> 374.2</td> <td class="xl25" width="73" align="center" height="16"> 349.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5000</td> <td class="xl25" width="73" align="center" height="16"> 378.1</td> <td class="xl25" width="73" align="center" height="16"> 359.9</td> <td class="xl25" width="73" align="center" height="16"> 373.2</td> <td class="xl25" width="73" align="center" height="16"> 355.3</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5100</td> <td class="xl25" width="73" align="center" height="16"> 378.5</td> <td class="xl25" width="73" align="center" height="16"> 367.6</td> <td class="xl25" width="73" align="center" height="16"> 371.3</td> <td class="xl25" width="73" align="center" height="16"> 360.5</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5200</td> <td class="xl25" width="73" align="center" height="16"> 377.3</td> <td class="xl25" width="73" align="center" height="16"> 373.5</td> <td class="xl25" width="73" align="center" height="16"> 371.8</td> <td class="xl25" width="73" align="center" height="16"> 368.0</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5300</td> <td class="xl25" width="73" align="center" height="16"> 375.6</td> <td class="xl25" width="73" align="center" height="16"> 379.0</td> <td class="xl25" width="73" align="center" height="16"> 368.5</td> <td class="xl25" width="73" align="center" height="16"> 371.9</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5400</td> <td class="xl25" width="73" align="center" height="16"> 375.1</td> <td class="xl25" width="73" align="center" height="16"> 385.6</td> <td class="xl25" width="73" align="center" height="16"> 368.4</td> <td class="xl25" width="73" align="center" height="16"> 378.7</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5500</td> <td class="xl25" width="73" align="center" height="16"> 371.3</td> <td class="xl25" width="73" align="center" height="16"> 388.8</td> <td class="xl25" width="73" align="center" height="16"> 364.2</td> <td class="xl25" width="73" align="center" height="16"> 381.4</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5600</td> <td class="xl25" width="73" align="center" height="16"> 371.2</td> <td class="xl25" width="73" align="center" height="16"> 395.8</td> <td class="xl25" width="73" align="center" height="16"> 361.7</td> <td class="xl25" width="73" align="center" height="16"> 385.6</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5700</td> <td class="xl25" width="73" align="center" height="16"> 366.3</td> <td class="xl25" width="73" align="center" height="16"> 397.5</td> <td class="xl25" width="73" align="center" height="16"> 356.6</td> <td class="xl25" width="73" align="center" height="16"> 387.0</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5800</td> <td class="xl25" width="73" align="center" height="16"> 360.7</td> <td class="xl25" width="73" align="center" height="16"> 398.3</td> <td class="xl25" width="73" align="center" height="16"> 354.2</td> <td class="xl25" width="73" align="center" height="16"> 391.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 5900</td> <td class="xl25" width="73" align="center" height="16"> 356.8</td> <td class="xl25" width="73" align="center" height="16"> 400.9</td> <td class="xl25" width="73" align="center" height="16"> 349.9</td> <td class="xl25" width="73" align="center" height="16"> 393.1</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 6000</td> <td class="xl25" width="73" align="center" height="16"> 351.6</td> <td class="xl25" width="73" align="center" height="16"> 401.5</td> <td class="xl25" width="73" align="center" height="16"> 335.9</td> <td class="xl25" width="73" align="center" height="16"> 383.7</td> </tr> <tr height="15"> <td class="xl25" width="73" align="center" height="16"> 6100</td> <td class="xl25" width="73" align="center" height="16"> 346.6</td> <td class="xl25" width="73" align="center" height="16"> 402.6</td> <td class="xl25" width="73" align="center" height="16"> 302.9</td> <td class="xl25" width="73" align="center" height="16"> 351.8</td></tr></tbody></table>

The big question is, what's it gonna cost me?!? Thanks!

 

http://www.chevyhiperformance.com/howto/97458/index.html

 

[FONT=Arial,Bold][FONT=Arial,Bold]If the manifold is used on a 1996 and later Vortec engine that does not have the[/FONT][/FONT]

[FONT=Arial,Bold][FONT=Arial,Bold]in-block bypass passage.[/FONT][/FONT]

I am using a 1966 block.



SPECIAL NOTE:
​

This intake manifold is primarily intended for use with Vortec heads on pre-Vortec blocks. Standard engine blocks route thermostat bypass water from the block directly to the water pump through the passenger side water pump mounting flange. ​

So this means we don't need the bypass. Yes?

​

​

 

Look... I don't care if anyone does or doesn't run the bypass or not. No skin off my nose either way.

But, the bypass only matters if you are running a thermostat. Most of the race engines don't run thermostats and run a water restrictor instead. The restrictor allows water to bypass right from start up. Engines with thermostats don't allow any water to move in the front of the intake if you don't run a bypass. The water gets very hot in the heads during warm up and since the water is not moving, the heads just keep getting hotter and hotter until enough heat wicks up to the front of the intake/thermostat and allows it to open. Thermostats open and close during engine operation and what will happen is that the temperatures in the heads will swing wildly and not as well controlled as it will if you DO run a bypass. The internal bypass in the older blocks is only on one side because that is all you need to let the water move.

For the last time, you don't have to believe me and many people think I am an idiot but I can tell you I have fixed MANY Vortech headed engines that have radical temp swings by adding a bypass to the front of the intake. It took me a while to figure out why that works but I know it has in more cases then I can count.

You can do what you want. If it is too much trouble to add a hose from the front of the intake to the water pump then I wouldn't do it.

Sorry I brought it up.

 

Thank you for bringing it up. I know its choppy waters here sometimes so I appreciate you riding the storm out.

These heads don't have 50 years? of experimentation on them like the standard SBC heads do. Stuff that's controversial today may be old hat in 5 years. I'm very excited!

 

Thank you for bringing it up. I know its choppy waters here sometimes so I appreciate you riding the storm out.

These heads don't have 50 years? of experimentation on them like the standard SBC heads do. Stuff that's controversial today may be old hat in 5 years. I'm very excited about the possibilites with these!

EDIT: I just called Edelbrock and they say to just plug this up if you don't have a vortec block because they have an internal bypass? that the newer block lacks.

That said, this wouldn't be the first time that mechanics have figured out something the manufacturer didn't know.

Thanks!

 

I'm not busting your balls, I'm just reading what you posted.

 

Not trying to stir up anything, just trying to avoid possibly burning up an engine...
Ive got an early '90s 350 (with the bypass hole to the water pump, but no thermostat) with a set of RHS vortec heads on it. There was no mention in the head instructions of having to run an external bypass from the pump to the intake, so I didnt run one. Ive had no problems with overheating and no odd temperature spikes.
The possibility that keeps popping into my head is that the external bypass is only needed when running a thermostat and using a block that doesnt have the extra hole at the waterpump, and has nothing to do with the heads.
This engine is slated to get a thermostat for the cold California winter, and if I have to install an external bypass, but Id like to know, rather than installing the thermostat, then having to drain the coolant a second time to install the bypass.

 

I have a 1999 model L31 Vortec engine, complete. It has the 880 block and DOES have the water bypass, HOWEVER, the heads do not have the hole to utilize it. Looking at the photos in the link above (from Bad Banana), it's easy to see why no one has suggested drilling the hole in the heads. It's not a tiny 1/8" steam hole, like the SBC 400. It's much larger and very close to the edge of the casting. I won't be poking a new hole. I'll run the bypass hose as intended by Edelbrock.

I also have news on another casting mark that you may see on Vortec heads. One of my pals has a SBC 400 that he ordered a set of prepped OE replacement Vortec heads for. They arrived with the correct casting number (10239906), bolt pattern, intake ports, etc., but they did not have the 3 sawtooth marks on the ends. They have a single round dome shape in the same place. I've never seen that mentioned anywhere else. These heads are "Hencho en Mexico".

 

1. If you don't run a thermostat, you will not have an issue.

2. If you run a thermostat and have heater hoses hooked up from one of the ports on the front of the intake and the return hose back to the water pump, you essentially have a bypass there and you will be fine.

3. If you have your coolant temp sensor in the front of the intake and you don't run a bypass, you will never know you have a problem because the hot water in the heads will never show up on your gauge (i.e. fat, dumb, and happy).

4. The ones I see with a problem have a thermostat, no external bypass (heater hose ect..) and have their temp gauge sensor mounted in the head. The temp gauge will scare you to death! I have seen head temp over 260F degrees then when the thermostat does open, it drops down to 140F and this goes on over and over just at idle. It gets slightly better once the engine gets completely heat soaked but the temps still swing more than it should.

If you don't fall into this last catagory, you probably will never see a problem.

Installing a bypass hose like a big block cures it completely. I have already shown you why. Go back and re-read my previous posts and study the pictures in the link from Nicky Fowler. I ain't makin' this shit up. Think about this... Why do big blocks run the external bypass hose? Do big blocks have an internal bypass passage anywhere? What is different about the way a big block is cooled as compared to a small block? (rememeber now... some folks think I am an idiot... )

As always, the choice is yours. I'll lead you to the water but I ain't gonna stand on your head and make you drink it.

 

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

 

So would you have to run the later style water pump? What's the difference between an early short w/p and a later Vortec pump?

 

What about drilling three or four 1/4" holes around the lip of your thermostat?
That alone should put the issue to rest.

 

the vortec heads need a lot of port work to really flow well, i did a set a few years ago, and i swore I'd never do another. they were one of the roughest heads I've ever seen, and I went through several carbide cutters working on them. if I were you, I'd take the advice on the first page and save up some cash then go the dart route.

 

The EQ's are a good head, under-rated by most guys. I am going with the 200cc x 54cc chamber "non-vortec" head on my 327. A lot of guys say they make the best Vortec style head around.

 

The vortecs do have excellent port shape and a great combustion chamber, but the castings are thin and prone to cracking, plus you need screw in studs, guide plates, valve spring pockets and valve guides cut down, and a vortec style intake. You're really better off with eq 180 or dart ss heads. Much thicker deck ,no mods needed, and they use a standard intake manifold.

 

It doesn't really matter what water pump you run. The Vortec pump doesn't have that lower hole that lines up to the block on the passenger side of the pre-Vortec block where the pump bolts up. The Vortec heads don't have the hole to line up with that passage that goes from the front of the block to the right hand deck. So that is kinda moot.

Drilling holes around the thermostat may work too. Problem is that is it ever goes bad after you sell the car and someone else changes it and doesn't drill the new one, they'll have the same issue. Also, if you are on the road somewhere and the thermostat sticks, unless you have a drill with you, you'll have to just take the thermostat out and limp home.

The permament fix from what I have found is follow the big block and run a hose externally. The Vortec truck engines all have the external hose/pipe if you go look at one.

 

Banana and Scotty,
Thanks for taking the time to shed some light on my bypass questions...since I do not know if my RHS heads have the holes in the deck surface like early production heads, I will be installing the bypass hose while Im doing the thermostat just to be on the safe side!

 

Yes it is aluminum and the 062 and 906 are cast iron.

 

If you ported them that much, you missed the point. Its not about max flow. There are all manner of aftermarket heads out for that. The vortec is flat out the best performing stock head gm ever produced. It combined the best of three previous designs.

The intake side should never be touched. It is heavily stippled to promote atomization and has a ramp protruding into the runner to impart specific flow charaacteristics. Remove these features and you actually reduce the efficiency below .500 lift.

The whole point of using them is to limit cost and extra work like porting. Simple recipe; stock vortecs, comp beehive springs and retainers, clearance guides for lift, clean up bowls and exhaust side a little. This can all be done for about $600. If you plan to port them all to hell, spend $1500 on some serious heads.

 

Yes I agree as well with Scottybaccus. Waste of time to port these heads. These heads are set up so very little is needed for maximum performance.With all the talk I hear about other aftermarket heads.The one thing that I like the most about these heads is the RPM range that they work in. because it is much lower then most aftermarket head. you can build a very drivable car with this setup and still have big HP.

 

that's what the customer brought, so that's what I ported. I was not impressed with them. as far as not touching the intake, ever..... I'll keep the 50 years of experience my dad passed on to me through the family business, thanks for the advice though.