Question: Cylinder Head Removal

[Vette79]

When removing the Cylinder Heads do you have to drain the block of coolant? If so, what is the best way to remove coolant from the block before removing the Cylinder Heads? I have already removed the top bolts and headers.

 

[JohnZ]

Yes, you have to drain the coolant to a level below that of the water pump holes in the front of the block or you'll dribble coolant from the heads and block into the cylinders when you break the gasket seal between the block and head on removal. Remove the block drain plug on each side just above the pan rail (use a 6-point socket), and you may have to poke a screwdriver or scratch awl through the hole to break accumulated crud loose before coolant comes out. There's over half a gallon of coolant on each bank, and the drain plugs are the ONLY way to get it out; those water jackets aren't cross-connected, so you need to drain both of them.

 

[duke94]

Drain the block as suggested. Also, replace the pipe plugs with some actual drain cocks and it will be MUCH less of a mess next time you have to drain it. Be prepared to have antifreeze running down your arm and all over the floor.

 

[Vette79]

Where can I get the drain cocks?

 

[Vette79]

Removed plugs and block drained. Thanks guys!!!

 

[duke94]

Where can I get the drain cocks?

Any auto parts store will have them. It has 1/4" NPT threads (pipe threads) and look like this.

http://www.zip-products.com/Zip/pro...alse&mscssid=B878A0CBDC764A358F7025A7DA88126F

 

[duke94]

Removed plugs and block drained. Thanks guys!!!

Did you get wet?

 

[Vette79]

Not real bad actually. I wore safety glasses to protect my eyes and removed the drain plug quickly and didn't get to wet. I probably will take your advice and replace plug with a drain cock. I'll remove the cylinder heads on Wednesday with my brother and start cleaning and preping for the build.

 

[Vette79]

Picked up the drain cocks today. Any need for thread sealant or tape? They are brass so I'm thinking it's not necessary.

 

[duke94]

Picked up the drain cocks today. Any need for thread sealant or tape? They are brass so I'm thinking it's not necessary.

It's always a good idea to use thread sealant on pipe threads.

 

[floopcom]

I would highly recommend NOT using teflon tape for this. Any time you're screwing tapered (pipe) threads into cast iron you stand the chance of cracking the cast iron if you screw the fitting in too far. The teflon tape makes the threads so slippery that it's easy to go too far when tightening the fitting.

 

[Vette79]

Cool. I'll use thread sealant but not the tape. I have not used any tape yet anyway. It has been the thread sealant in a tube that I have been using on all my threaded fittings. I suppose I can use this on the fuel line fittings as well???

 

[Vette79]

Cylinder Heads are off and new Drain Cocks installed in the block.

 

[Bolisk]

What did you do with the old anti-freeze? I did this a while ago. . .and just have old milk jugs filled with anti-freeze sitting in my garage. . .

Anyone have any idea where to take it?

 

[duke94]

What did you do with the old anti-freeze? I did this a while ago. . .and just have old milk jugs filled with anti-freeze sitting in my garage. . .

Anyone have any idea where to take it?

I'm lucky as I can take it to work and dispose of it. I think many of the quick oil change places will take it for a small fee.

 

[JohnZ]

Cool. I'll use thread sealant but not the tape. I have not used any tape yet anyway. It has been the thread sealant in a tube that I have been using on all my threaded fittings. I suppose I can use this on the fuel line fittings as well???

Fuel line fittings are SAE inverted flare, and seal at the flare, not at the threads like NPT pipe thread fittings do. Just use a little pipe dope (not tape) on the threads to lubricate them - reduces thread friction (and the chance of galling the threads), and makes it easier to get a good mechanical seal at the flare seat without having to use a lot of torque.

 

[Vette79]

I'm lucky enough to have my neighbor dispose of the liquids for me at his shop. Well, all thats left in the car now is just the block with the crank and pistons. We spent the later half of the day just cleaning and preping. We did make an unusual find that maybe someone can elaborate further for us. There are numbers stamped on top of the pistons that lead us to believe that the motor has been rebuilt before. The numbers indicate forged aluminum pistons bored .030 over. The head gaskets that we removed were Fel Pro gaskets. We checked everything else and so far this looks like the only change. Not sure if this is a good thing or a bad thing? Also, on an original OEM cam were there numbers stamped on the end of it?

 

[JohnZ]

It's been bored .030"-over and rebuilt. If the cam is the original 1979 L-48, it will have a casting number "6930" raised on the core surface, and will also have a raised horizontal "diamond" symbol on it. Most OEM cams didn't have anything stamped on the end, as they were identified by the casting number on the core (GM used different core castings for every different cam part number to minimize machining).

 

[Vette79]

It's been bored .030"-over and rebuilt. If the cam is the original 1979 L-48, it will have a casting number "6930" raised on the core surface, and will also have a raised horizontal "diamond" symbol on it. Most OEM cams didn't have anything stamped on the end, as they were identified by the casting number on the core (GM used different core castings for every different cam part number to minimize machining).

John,

Here's what is stamped on the cam we pulled out. Also, any idea what the TQ specs would be for a Stewart Stage 2 Aluminum Water Pump Bolts?

 

[WolfPlayer]

Jeff,

I grabbed some pics of the cam core - including the various markings on it (those pics should be on your camera too). We should be able to verify by looking at those pics (or just grabbing the cam and examining it).

... my first post

Tim