Vortec Bypass Hose/heater hose

[Tabasco]

I bought a vortec crate engine complete with accessory drive and water pump. Instructions say to run a bypass hose from the water pump to intake. There is only one place to attach a hose on the water pump. If I do that where do I connect my heater hose?

I know there are water pumps with two openings in the top for hoses. But this is the pump which Chevrolet supplies with the engine and I would like to use it and not have to buy another. Any suggestions?

[markm]

Many Chevy trucks have heater return hose piped into the radiator. The inlet to heater core comes off front or rear of intake depending on year.

[Tabasco]

Thanks. After I posted the question i googled the water pump part # and found it is for a 88-95 truck. I checked my motor manual for Chevy trucks and see that what you said is true about the line going to the radiator. I don't plan on modifying my radiator. I may have to get another water pump.

I bought this engine because it was complete from water pump to flex plate so the install would be easy. I keep running into little things that make it harder.

[55 Rescue Dog]

I was wondering why a bypass hose to the intake? That would make sense if you were not using a heater core, which wouldn't allow coolant to circulate through the block when the thermostat is closed. I would think the heater core have the same function as a bypass hose. On my 350 LT-1 I'm running a Stewart aluminum pump with no external lines, or heater, which I solved by using a bypass thermostat with bleed holes in it to circulate coolant in the engine until it warms up and opens. Also eliminates the air lock you get when filling the cooling system up. Not familiar with the Vortec engine though.

[markm]

My 1972 Cheyenne Super and both my 1987 V1500 GMCs are plumbed this way so it is nothing new. My 1972 K/5 Blazer is not, might be due to no factory A/C.

[chevynut]

I think it would be pretty stupid to use the heater core for a bypass on a hot summer day, and if you drill a hole big enough in the thermostat to circulate much coolant, you might as well not have a thermostat. Both "solutions" are nonsensical and don't solve your heater problem.

Seems like you should be able to find another port on the intake to get hot water for your heater. Also, you could splice in a "tee" into your lower radiator hose for the heater return.

[55 Rescue Dog]

I think it would be pretty stupid to use the heater core for a bypass on a hot summer day, and if you drill a hole big enough in the thermostat to circulate much coolant, you might as well not have a thermostat. Both "solutions" are nonsensical and don't solve your heater problem.

Seems like you should be able to find another port on the intake to get hot water for your heater. Also, you could splice in a "tee" into your lower radiator hose for the heater return.
It wasn't my idea anyway, I gathered that info from the Stewart Components site. I always thought on every small block car I've ever had, it sure looks like the coolant constantly flows through the heater core. I sure don't recall any shutoff valves to block the coolant flow. I thought they just blocked the hot air from coming in the car?
https://www.stewartcomponents.com/index.php?route=information/information&information_id=11

[markm]

iI believe my sbcs in trucks rely on bypass. in block and water pump , The extra hole in drivers side water pump mounting surface,

[55 Rescue Dog]

iI believe my sbcs in trucks rely on bypass. in block and water pump , The extra hole in drivers side water pump mounting surface,
Yes there is a bypass hole there on most pumps, but maybe not all. I can see it circulating coolant in the block, but maybe it's the heads that need flow too, by using the heater core supply to the inlet on top of the intake manifold until the thermostat opens? That would equalize engine temperature during warm-up I would think. Don't really know for sure how it all works, but it works is all.
The reverse cooling system that Smokey Yunic designed, that GM adopted on the mid-90's LT1 was a unique, complex system that flowed coolant through the heads, and then to the block. They were able to bump the compression ratio by doing so I remember reading many years ago.

[Rick_L]

If the water pump is for an 88-95 truck, it is reverse rotation for a serpentine belt setup. Are you using a factory serpentine accessory drive? If not, you need to buy a water pump suitable for the old school v-belt drive. Many of those water pumps have two ports on them, one near the suction hose where the heater return hose is traditionally connected, and one on top that is typically plugged. You can use the one on top for the bypass hose.

There's a lot of bogus info in the above posts.

[55 Rescue Dog]

Just saw this 33 page thread from 2011 pop up all about the subject.
https://www.trifive.com/forums/showthread.php?t=59036

[Tabasco]

Yes it is the serpentine drive with a reverse rotation pump. On the other site I was given a link to that 33 page thread. Just about everything thing was tried on that thread. I think I will go with the suggestion of putting a tee in the lower hose for the heater return hose.

The simplest plan would be for Chevrolet to make a water pump with two holes on top for this application. That would sure help us who put new engines in old cars.

Thanks to everyone for your replies.

[chevynut]

I always thought on every small block car I've ever had, it sure looks like the coolant constantly flows through the heater core. I sure don't recall any shutoff valves to block the coolant flow. I thought they just blocked the hot air from coming in the car?

If you actually believe that it shows again how uninformed you are about cars. Virtually EVERY car has a coolant control valve to stop coolant from flowing into the heater core. If they didn't, you'd get heat in the passenger compartment from the core, but without the blower. Vintage Air supplies a control valve and even the stock heater core from 60 years ago has a valve. How else do you control air temperature? As for the holes in the thermostat, they're not needed with a proper bypass and do cause longer warm-up time. Lots of posts on the forums about that. A tiny hole to pass air may help purge the system. Some guys actually believe that restricting coolant flow improves cooling. LOL:D

[BamaNomad]

CN... again you're passing along very good information using your talent and style... making the receiver feel good by being made smarter by you~ *applause* .... :(

[markm]

If you actually believe that it shows again how uninformed you are about cars. Virtually EVERY car has a coolant control valve to stop coolant from flowing into the heater core. If they didn't, you'd get heat in the passenger compartment from the core, but without the blower. Vintage Air supplies a control valve and even the stock heater core from 60 years ago has a valve. How else do you control air temperature? As for the holes in the thermostat, they're not needed with a proper bypass and do cause longer warm-up time. Lots of posts on the forums about that. A tiny hole to pass air may help purge the system. Some guys actually believe that restricting coolant flow improves cooling. LOL:D


I do not believe my 67 Camaro or 72 Blazer either one have a heater control valve, for that matter neither does my 74 Z28 and its a factory AC car.

[Tabasco]

Well I have bypass hose. Until this week I didn't even know I needed one. I learned a lot about vortec engines that I didn't know.

My intake had three holes. I originally used them for a stock temp sender, an auxiliary temp sender and heater. To add the bypass I put a tee in one hole and used that for a temp sender and the bypass.

9783

I'll run one heater hose from the intake and the return line to a connection on the lower hose.

Now on to the next task. There are sure a lot of pieces to a '56 Chevy. They come apart a lot quicker than they go back together.

[55 Rescue Dog]

If you actually believe that it shows again how uninformed you are about cars. Virtually EVERY car has a coolant control valve to stop coolant from flowing into the heater core. If they didn't, you'd get heat in the passenger compartment from the core, but without the blower. Vintage Air supplies a control valve and even the stock heater core from 60 years ago has a valve. How else do you control air temperature? As for the holes in the thermostat, they're not needed with a proper bypass and do cause longer warm-up time. Lots of posts on the forums about that. A tiny hole to pass air may help purge the system. Some guys actually believe that restricting coolant flow improves cooling. LOL:D
I will never know as much as you Anut about cars, and surely you must know there are 2 types of heating systems used on cars. Not a lot of info out there I could find on the subject but there are water valve systems, and air blend systems to control the heat. One of the advantages of the air blend system is it adds cooling capacity since the heater core is also a radiator all the time, and diverting air with blend doors to control the cabin temp. Do modern cars even use a water valve like the old cars did? I don't ever recall mentioning restricting coolant flow to improve cooling. That's what some people do when they eliminated the thermostat which I think is a bad idea. The thermostat is a restriction even when fully open, which is the reason they use restrictors to control the flow to the same flow rate, with no bypass hose required. The 3/16's inch holes are required in the thermostat on engines with no heater, and no bypass hose to circulate coolant to the cylinder heads. Otherwise the cylinder heads will overheat before the thermostat can open. The bypass holes do slow down warm up a little, but it works.
So, I'm guessing you surely have a better explanation?
https://www.howacarworks.com/basics/how-car-heating-and-ventilation-systems-work

[markm]

Just saw this 33 page thread from 2011 pop up all about the subject.
https://www.trifive.com/forums/showthread.php?t=59036

Talk about bogus info this thread is full of it, all SBC factory blocks I have ever seen have the bypass cast in them, the Vortech ones do not have it in w/p or cyl head.

[55 Rescue Dog]

On this setup with no heater or hoses, I had to use a bypass thermostat. The radiator is below the top of the engine so I needed to fill it from the T-stat housing. I didn't want to use a surge tank so I ended up using a Moroso filler neck housing with a high pressure cap, and a lower pressure cap on the radiator with an overflow tank. I can fill the whole system with no trapped air, screw the cap on and it's good to go. I can, and have drained all the coolant with petcocks on the block, and refilled without spilling a drop. BTW, do not use the Summit water pump that failed at 150 miles, or the stainless upper hose with adaptors, and worm clamps that failed at 200mi. It now has a high pressure Goodyear hose, and constant tension hose clamps. This is a street car designed to feel/look like a race car, and it does just that. Love it, or hate it, it is a freaking hoot to drive even at 55. Even though it didn't pan out, I wanted this car to look like a 55 Chevy. Only one piece of glass, no AC, with no stereo that you could even hear, no remote controls, etc. Just a simple car built from a pile of steel.
My 1930 Model A was a lot like that, but much more scary to drive at any speed.
https://bangshift.com/bangshiftapex/car-feature-street-legal-circle-track-camaro-unique-homebuilt-corner-burning-monster/
978697879788

[markm]

Well I have bypass hose. Until this week I didn't even know I needed one. I learned a lot about vortec engines that I didn't know.

My intake had three holes. I originally used them for a stock temp sender, an auxiliary temp sender and heater. To add the bypass I put a tee in one hole and used that for a temp sender and the bypass.

9783

I'll run one heater hose from the intake and the return line to a connection on the lower hose.

Now on to the next task. There are sure a lot of pieces to a '56 Chevy. They come apart a lot quicker than they go back together.

looks like that will work in spite of all the bogus info being put out.

[55 Rescue Dog]

looks like that will work in spite of all the bogus info being put out.
My point with the bypass thermostat still stands. Looks cleaner, only adds a few minutes to warm-up, then the t-stat, and fan take it from there anyway. I have no idea how to calculate the volume of flow through three 3/16in holes in the t-stat at whatever the water pump pressure is though? I have a pressure gauge with a low pressure light, installed in my cooling system, but I get weird readings with it mounted above the thermostat. I need to move the gauge port below that to read cooling system pressure I think.

[Rick_L]

I don't think holes in the thermostat are the end of the world, but your comments about the uncertainty of the flow volume makes it a crap shoot doesn't it? They can be made too big.

The engine is certainly going to warm up slower than otherwise if your bypass is to the radiator.

Your comments about pressure don't make any sense. Remember too that race setups that monitor water pressure don't usually use a thermostat.

Why not just install the bypass hose like the factory did and move on?

[markm]

My point with the bypass thermostat still stands. Looks cleaner, only adds a few minutes to warm-up, then the t-stat, and fan take it from there anyway. I have no idea how to calculate the volume of flow through three 3/16in holes in the t-stat at whatever the water pump pressure is though? I have a pressure gauge with a low pressure light, installed in my cooling system, but I get weird readings with it mounted above the thermostat. I need to move the gauge port below that to read cooling system pressure I think.

My comment was not directed toward you it was directed toward the statements in that link about Vortech blocks not having bypass passages drilled. Heads and pumps are not drilled but blocks I have seen are drilled.

[55 Rescue Dog]

Since it was mentioned earlier in the thread that, EVERY car has a heater control valve, I was wondering how on modern cars they control the cabin heat temp with dual-zone climate control, etc? Do they use multiple servo operated heater control valves for that? I can't seem to find a good example of how automotive HVAC system really works. Never gave it much thought before, as long as it got warm when it was cold outside, and cold when it's hot. I like controlling temperature with the windows.

[Rick_L]

EVERY car has a heater control valve,

Most 60s GM cars didn't have a heater control valve. I don't know when they went back to one if they ever did.


I was wondering how on modern cars they control the cabin heat temp with dual-zone climate control, etc? Do they use multiple servo operated heater control valves for that?

They use servo operated "doors" not valves. In other words they control the flow of hot air (and cold air), rather than coolant flow.

[55 Rescue Dog]

Most 60s GM cars didn't have a heater control valve. I don't know when they went back to one if they ever did.



They use servo operated "doors" not valves. In other words they control the flow of hot air (and cold air), rather than coolant flow.
It reacts quicker I think, rather than waiting for the heater core to warm up, and back down.

[chevynut]

Most 60s GM cars didn't have a heater control valve. I don't know when they went back to one if they ever did.
They use servo operated "doors" not valves. In other words they control the flow of hot air (and cold air), rather than coolant flow.

A lot of them did have heater control valves, especially with A/C and on cars in the late 60's cars....

https://www.carid.com/1964-pontiac-bonneville-heater-control-valves/

https://www.ss396.com/chevelle/ACV-1901.html?gclid=EAIaIQobChMImq6thfnx4gIVEavsCh0CAg cFEAQYASABEgLNX_D_BwE

https://www.ss396.com/camaro/ACV-1901.html?search_query_insert=Y&search_query=heater%20control%20valve&search_results=2&conversion_insert=Y&conversion_product_id=135&cartype=camaro&year=0

https://www.ss396.com/nova/ACV-1901.html?search_query_insert=Y&search_query=heater%20control%20valve&search_results=2&conversion_insert=Y&conversion_product_id=135&cartype=nova&year=0

[Tabasco]

I received the part I need to connect the heater return line to the lower radiator hose. I'm glad something was available so I wouldn't have to have one made.

9796

One more problem solved, 10,000 more to go.