Water pump questions

I have 2 questions relating to the gen2 water pumps.

For the first question I'm looking for info from someone who may have an LT1 water pump sitting near by. I know somebody has one laying around to peek at

1) Do the tubes that run to the heater hose/overflow tank look like they are pressed in or welded in? I'm pretty sure the tubes are press fit since they are steel and the pump is aluminum, but I've never messed with one to find out for sure. I'm putting up the highlighted pic for those who don't get which tubes I'm talking about.




And for the second half of this double feature. This question is for those who are more advanced with their mods.

2) For anyone who's done the electric water pump, what is the correct way of removing the gear drive from behind the timing cover and putting in a cam button? I'm sure someone has done this and I'd love to know the best way to do it so that I could use a more traditional cam and also eliminate an oil leak. I've heard people weld a plate over the hole in the timing cover, but how do you deal with the issue of the cam being at the right depth? Would it be easier to just get a timing cover from a gen1 and drill the hole for the Opti drive?

Any help would be greatly appreciated.

Why are you so interested in changing the dynamics of the water pump. A stock LT1 water pump is good for 100k+ miles and even rebuilt units are cheap enough. Why bring an electric drive into the equation? The tubes are pressed in.

I'm on a replacement pump now which seems to be working well. I'd be more confident in how well if my temp guage worked, but the car sounds like it's ok and there's no leaks from the weep hole so I assume it's fine

I'm looking at a really big and complicated idea for the cooling system which would serve no purpose other than to see if it actually works, which is why I wondered about those tubes

The electric waterpump question is to allow the use of a gen1 hydraulic roller camshaft since the aftermarket LT shafts are not really designed for the little L99. Basically any LT cam other than stock is probably going to be too much cam for my engine, even after it becomes a 305. Plus I want to try flipping the firing order a bit and see what happens

Since I can't do what I want with the drivetrain any time soon I'm going to see what exactly is possible with the itty bitty motor. And if something eventually does blow up then I'll just be forced to carry out my master plan

And if Doug lets the cat out of the bag I'll tell everyone what a horrible person he is

I am sorry to say that if you are planning that kind of time and effort, why not just make you master plan an LT1 and 4l60e swap.

I don't think you could just drill a hole for the opti, there is a lip for the seal.

From what I remember you have to pull the intake to push the WP gear out. IIRC one person said he was able to remove it without removing the intake. Some weld up the hole, some have used freeze plugs, some have just used JBweld wtith a flat plate and some have just left the gear in there. Look on camaroz28.com and also search for folks that changed from nonvented to vented optis.

If you want to go cheap I'm with Bill. A new opti will probably cost more than for what you could get a LT1. If you want to do something different then that's different.

You need a cam that will accept the opti drive pin. I thought only LT1 cams were drilled for this. Am I wrong?

edit:

How are you going to use a cam button and still drive the opti?

For the hose tubes I'm thinking of having them yanked out of the waterpump and having plugs put in their places to eliminate the heater system completely. I'd rather not redneck it and have a looping hose dangling off the front of the engine. To pull this off I'm thinking I need to switch to a heavyduty radiator with a traditional fillerneck and overflow tube (which I'll need for my fallback plan anyway). Then I can run an aftermarket catch can for the radiator overflow as well as the steam tube off the intake manifold.

As for the cam issue, I'm looking at ways of getting rid of the opti and playing around with the idea of something like the ls setup eficonnection is selling. Minus all the overpriced pieces of course. I figure junkyard pcm, coils, wires, and anything else I need to get should drop the price down to just above the cost of the kit iteself. Or I could try to dig up the old info on drilling the manifold for a traditional distributor and run the vortec van distributor to fire the ls ignition system.

And my fallback plan involves a carbed big block with a th400. It'll be roughly the same cost as an LT1 but alot more fun and easier to work on. Of course the install will be a nightmare

I have a new question that is part of the same big idea so I'm adding it to this thread.

Does anyone know how well a Camaro radiator fits into the core support on our cars? I'm looking for a standard style non-preassurized radiator with a cap and the LT1 Camaros appearently have that feature. Any insight would be helpfull. And I know someone has the info since a few of you cut up Camaros for fun

bammax wrote:

I have a new question that is part of the same big idea so I'm adding it to this thread.

Does anyone know how well a Camaro radiator fits into the core support on our cars? I'm looking for a standard style non-preassurized radiator with a cap and the LT1 Camaros appearently have that feature. Any insight would be helpfull. And I know someone has the info since a few of you cut up Camaros for fun

Again I ask. Why? The closed loop system of our cars is a great thing once you understand how it works and how to burp the system. The camaro radiator will not fit. Ask me how I know. It is not as tall, and if memory serves me, it is a bit too wide.

Now as far as the cams are concerned. I do not want to feed you with mis information, but I am damn sure all LT1 cams will work with the L99. Some of the more aggressive ones will be too much, but they will work. Back in 96-97 Chevrolet race shops took an 2 L99s and built one of them to a 5 liter size and used the GMPP LT4 hot cam, LT4 intake, heads and LT1 crank. That engine went into a yellow 55 chevrolet 210. The other was kept stock size but with LT4 hot cam, and a pair of LT1 heads and intake and was put in a test mule 94 Impala SS wagon. This car eventualy got a LT1 done up with the LT4 parts and T-56.

Now back to the water pump. You can buy a electric water pump that replaces the front plate of your water pump, and requires you take the pump housing off to do some alterations to it, but unless you are making alot of hp or drive it real hard, I can't see spending that kind of money and now adding an additional system to your car with the electric portion of it. Many gear driven stock units have lasted 100k even after being beat on. They are no worse than the old belt driven style as far as reliability. The only problem is where the rocket scientists at GM decided to put the distributors on the LT series engines.

Well I decided at some point in the next year I'm pulling the entire heater system from the car and plugging the heater tubes in the waterpump. I'm then putting in a radiator with a fillercap and an aftermarket catch can to replace the plastic reservior. I'm figuring run an overflow tube from the radiator to the outlet port of the catch can (bottom) to allow for any coolant overflow as well as let the coolant return to the system on cool down. Then I'll run the steam tube to the inlet (top) port to allow the steam to escape without allowing coolant to backflow into the head from the catch can.

Other than Billy saying it's all pointless are there any flaws with my idea that I'm missing? And it may be pointless now but I'm considering it experimentation/prepwork for my next drivetrain which will have a more oldschool install (ie. less wires, hoses, plastic bits)

This has nothing to do with water pumps but it is cooling system related and important to my grand scheme.

I know a few of you guys had '91-'93 Caprices so I could use some info. What's the deal with the heater hose into the radiator? I've been looking at radiators for a '93 and they all mentions this:

Notes Heater return line and coolant level sensor on right hand tank

I understand the level sensor being in the radiator as opposed to the overflow tank, but I'm not used to heater hoses passing through the radiator. Any insight on how this system works would be helpful.