external bypass line "vortec heads"

[Francis F.]

I am looking for the best way to accomplish this task,engine is a new 350 crate .
I'm all ears....thank's Francis

[Joe L.]

Re: external bypass line "vortec heads"

I am looking for the best way to accomplish this task,engine is a new 350 crate .
I'm all ears....thank's Francis

Francis------


I don't know of a Vortec intake manifold that has provisions for external bypass in the traditional location. There may be one but I don't know of it. I suppose one could use the water temp sender fitting presuming that one didn't need it for the temp sender (i.e. 1968+ applications). This fitting is usually present on the driver side of the thermostat flange on most manifolds.

Otherwise, you could rely on internal bypass which is what most small blocks utilized in the first place. I'm sure the crate engine is so-equipped.

[Jim T.]

Re: external bypass line "vortec heads"

I am looking for the best way to accomplish this task,engine is a new 350 crate .
I'm all ears....thank's Francis

Is the crate engine a GM prepared crate engine? If so which one? My ZZ GM crate engine came with aluminum heads and did not have external bypass line.

[Francis F.]

Re: external bypass line "vortec heads"

Joe are you referring to the small hole on one leg of the water pump,(which is on the driver side of the pump)just below the bottom fastening bolt of the water pump ? Would that hole represent the internal bypass ?
Francis. ps.My original hook up on (1966 a/c car) the line from the heater vacuum valve ran back to the intake manifold adjacent to the thermostat house,which I was planning to do with the vortec intake ,there is a plug on top of the intake .a 90* fitting would be required for this return line. Can you picture this ,and is it a good solution ??

[Joe L.]

Re: external bypass line "vortec heads"

Joe are you referring to the small hole on one leg of the water pump,(which is on the driver side of the pump)just below the bottom fastening bolt of the water pump ? Would that hole represent the internal bypass ?
Francis. ps.My original hook up on (1966 a/c car) the line from the heater vacuum valve ran back to the intake manifold adjacent to the thermostat house,which I was planning to do with the vortec intake ,there is a plug on top of the intake .a 90* fitting would be required for this return line. Can you picture this ,and is it a good solution ??

Francis-------


Yes, the small hole in the block and waterpump leg is the internal bypass. All small blocks used internal bypass except some 1961-67, primarily with aluminum manifolds, and some MD/HD truck applications. All 1968+ small blocks used internal bypass except some MD/HD trucks.

I think I understand what you're referring to as far as the heater hose connection goes and, yes, I think your solution should work just fine.

[Francis F.]

[Francis F.]

Re: external bypass line "vortec heads"

Jim, my crate engine is #19210008, 350/330hp,H O deluxe ,long block less starter/water pump/fuel pump,going in a 66 A/C auto car.Also engine has iron heads...

[Joe L.]

Re: external bypass line "vortec heads"

Joe, thank's , you put me at ease.I will put all back as I found it,….return from heat valve in to top of vortex alum. intake.
now trying to get the correct water pump,it looks like the alum.#19168604 (short leg) could be the one all but the .750 " shaft diameter will have to check my fan clutch to be sure they are compatible.
thank's again ,Francis

Francis-------

The Vortec intake manifold should have fittings into the water passages on both sides of the thermostat housing. The one on the passenger side would be the most convenient to connect to the heater hose. The one on the driver side would be used for the temp sender. I suppose it could also be used for external bypass but you don't really need to do that. The internal bypass will work fine; millions of small blocks used it.

As far as the water pump goes, I believe the GM #19168604 does have a 3/4" pilot shaft. While it does have dual bolt patterns on the flange, I do not recommend using it for your application for two reasons. First, I do not recommend enlarging the pilot shaft orifice on your stock pulleys to 3/4". Second, even if you did that, I think you will find that this pump will not have a flange location that will cause your pulleys to align. I believe the flange location on this pump is for the 1971-82 Corvette application. This application spaces the flange out slightly further than the earlier short leg pump. A better plan would be to obtain an aftermarket short leg aluminum pump with 5/8" pilot shaft and with the hub in the correct location for your application. Many choices available from Edelbrock and others. You could also use a high quality, rebuilt original cast iron pump.

[Francis F.]

Re: external bypass line "vortec heads"

.Joe thank's most helpful ,trying to pick one now...
Francis