I just completed an expensive top-end rebuild of my 79. Getting ready to break her in. I have a question related to coolant flow. During the build I drained all the coolant from the block. For initial start-up and break-in should I have coolant in the block? I'm guessing just pour coolant into the intake manifold where the thermostat housing is? Also, are there any tips or tricks of the trade that anyone wants to pass along for break-in...
Are you breaking in the cam?
If you have a roller cam, no break-in is necessary.
If you are using flat tappet hydraulic lifters it is.
Fill the radiator until full, and the overflow tank.
Squeeze the upper radiator hose a few times to burp the air out of it. It will not fill with coolant because it is the highest point in the cooling system.
Start the engine with the radiator cap off, and note the level drop in the radiator, refill until the radiator is full then put the cap back on. After that, thermal cycling of the system will refill the radiator from the overflow tank.
If you are breaking in the cam, run at 2,500 RPM for twenty minutes.
I was concerned with coolant on my engine rebuild start up and having air pockets in a dry block. What i did was, filled through the thermostat housing opening in the intake manifold untill it was topped off, installed the thermostat housing cover, rad hose, and then filled the rest of the radiator. Started engine with rad cap off and waited for the water level to stabilize then added more water till it was full, put on the cap and completed the engine break in sequence.
Yep, flat tappet cam. I think I will pour some rad fluid into the block before startup and break-in. Thanks for your input. Really nervous as to if it will start and what problems we may encounter. Break-In is on Monday. Here is a link to my Project Build if you have not already seen it: http://www.corvetteactioncenter.com/forums/showthread.php?t=103334
"Some" won't get it done - the cooling system needs to be full, especially if you have a new cam and lifters to break in; fill it as 80RedL82 noted above. If you have the static timing set correctly and fill the float bowl through the bowl vent, it'll start right up.
It's the tube that sticks straight up just in front of the choke blade; use an infant feeding syringe or a plastic ketchup dispenser bottle like you find on the table in a burger joint.
John, thanks. I thought it was that tube but wasn't quite sure. I pulled the thermostat housing and it is topped off with coolant. I think we are ready for Monday. Is there anything else we need to be prepared for or aware of??? I'm sure I'll be asking questions related to tuning...
On a first start up, I would watch for fuel leaks.
Make sure your clamps and connectors are tight.
Check them again after a few days, they can come loose after warming and expanding.
Break-In was very successful today. She started right up and kept her at approximately 2600 RPM's for 20 minutes. A minor fuel leak from the fuel line at the carb and a minor coolant leak at the nipple on the intake manifold. Temperature during Break-In was around 240*. Pretty high. What's the easiest way to ensure no air in the cooling system? The Vette sounded real good and we should have a video to post soon of the Break-In...
Assuming you fixed the coolant leak and the system is airtight, I wager that most of your overflow tank will suck back into the system. Next time you fire it up, the temp. should be normal.
Every time you cycle the engine a little more air will burp out, and a little more coolant will replace it.
Well, re-installed fan and fan clutch, plugs, plug wires and looms, and coolant nipple on intake manifold. Re-torque timiung chain cover and fuel pump. Replaced fuel hose to fuel pump. Almost done and almost time to start her back up again for tuning and leak check. PICS to follow soon. Hopefully temperature will go down...
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