Anyone who has bypassed their heater, can you tell me how you did it? My 92 heater has been bypassed and I am thinking of reversing it. This is a 383 stroker motor with a Stage VI Blowerworks supercharger on it- tubes everywhere and I'm having trouble finding out what to do. I dont much plan to drive in the Winter in Indiana and I would be concerned if it would have any effect on the engine. The A/C compressor has been unplugged too but thats simple if I need it. Anybody have this issue and think I should just leave it be- wear bigger coat?????? thanks

 

Dale Meers( KY) racing put it together with the prior owner

 

I can try to help but I don't have a 92, even though the philosophy is sort of the same.
Where I highlighted with the arrows, your heater core should be at the firewall sticking out.
Both in and out.
Where the line across the bottom looks like your in and out lines that go to the water pump
ect. Look for a u shaped connector or capped off lines as the hot water would need to flow through the heater cor(behind the firewall.
Goo Luck



Here is a look at a simpler system on my 85, this not a fully stock setup. But you can see .

 

Hey pnewt, I have an L98 but think the principle should be straight-forward.

First, from this LT1 line-drawing (though of an F-body), you can see the general heater cooling path....



I'm going to assume water is supplied/returned through tubes 1 & 2 of the water pump...



There are probably several ways to "skin this cat" but the first likely involves looking through your "maze of craze" to see if you think the hoses/routing still exist? Specifically, I COULD imagine plugs being inserted IN THE WATERPUMP to shut off water AT THE SOURCE.

Secondly, one common reason for a bypass is to "cure" a leaky heatercore until it can be addressed later on. That means connecting the inlet/outlet hoses BEFORE they penetrate the PS firewall. This would "bypass" water from entering the heatercore...then returning to the waterpump.

I'm not sure if any other method exists...though we should assume it. Maybe people "block" the water path versus bypassing around it? The biggest question is WHY the water was bypassed? Was it for a wuss afraid to dig in and repair the heater core? Was it related to the blower installation? Was it a space issue? (I don't know but can water be needed/used on a blower? Could it be robbed from Peter to pay Paul?)

Like I said, look to the source first and see if you can see the components of routing from the waterpump...to the firewall...and back.

 

Great info guys, pics do wonders for us 'old guys' The heater was bypassed before the engine was modded. Prior to me owner never messed with it either. I'll look at the areas you marked and go from there. My older(71,76 cars were so easy to see everything) This one looks like I need a plumber to work on it!!!! Appreciate all the help you guys give.

 

When I bought my 92 it was bypassed due to a bad core.
First thing I would do is pressure test the heater core, no since making things worse.

The line from the throttle body goes to the heater core. Or from the tee in the upper hose if bypassed.
The "J" shaped hose from the heater core goes to the surge tank. The Hose from the surge tank goes to the block at the water pump.

You'll probably need to order a J hose.
The Hose from the throttle body to the lower heater core fitting has a check valve. Arrow goes towards the heater core.

 

If you take the expansion tank off the heater core connections are easily accessible.

The big difference between an LT-1 Corvette and the drawing above is the expansion tank is piped between the heater core outlet and the water pump.

 

Do people bypass the TB on LTx cars too? If so (like I did on mine), you'd have to figure that into the possibilities too.

 

Nobody bypasses the heater core because they want to freeze their butt off in cold weather. I've never seen one that was bypassed that didn't have a bad (leaky) heater core. Start by deciding if you want to invest the time and effort in that repair.

 

That was the first thing I changed when I bought my Corvette for 1600.00.
I figured that should break me in. 2 days worth.

 

you got me thinking now I'll look it over and decide whether to mess with it. It sits in a heated garage most of every week, its certainly not a DD but have always just taken my cars out on warm winter days. This is basically a race car so its just fun to drive. More fun than my Z06 and the 2 Lingenfelters I've owned. C4's make you drive them and I like that. Even better than the ZR1 I owned years ago. I guess my old age likes all the horsepower Thanks

 

In your particular build I believe it's a 'rush to judgement' to just assume there's an issue with the heater core. I'd be inclined to believe it was more practical to do the build without. The C4 in '92 was plumbed very differently than the F-body routing that's in post# 5 and maybe, just maybe the C4 LT1 pump wasn't even used. It's very difficult in your snapshot to actually determine that.

If you really want heat you just need to maybe think it out. For sure it might likely not be easily accomplished but I don't believe that you assume the core bad. I think you check it before moving forward.

The '92 LT1 C4 pump was a 'one year' pump and looks nothing like the pump in #5 either. So you need to determine which pump is actually there. There's likely 4 or 5 configurations and I'm sure the choice was for the 'engine build' rather than HEAT!!!

 

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There is no HP to be gained by bypassing the heater core - so there is probably some reason the previous owner bypassed it. Maybe it leaks - maybe there is blend door problem, and it heats - even when no heat is requested. But - I'd check before blindly reconnecting it.