At work we have a 42 to 48 Ford flathead with Edelbrock aluminum heads. The ones with the water necks in the center. We filled it with water and started it for the first time today. This was a new built engine, 60 over, Supposedly built by a local flathead guru and been sitting for about 5 years. We put on the heads, and torqued to 55lbs. The studs were already on the engine. On the left side we have water leaks on about 8 studs. No leaks on the right side. Felpro gaskets. We pulled the head and before we re assemble, wondering what everyone does to stop the stud leaks. This engine has the usual block cracks from the studs to the water holes.
GM brown “pills” all SBC’s where the bolts go into the water jackets have the same problem and use coolant. Personally I use studs with SBC’s and Permatex #2. These are Bar’s Leaks…same thing.
Pull the studs and goop the threads with the stinky brown Permatex. Make sure to get it on the threads and not too much on the head if you don’t remove the head. Then I use Silverseal powder in the water. Will probably take a while for seeps to stop. *** Do not run a tap in the stud holes, ever. They are a close tolerance thread that is meant to fit tight.
Thread chasers are ok but most don’t own them…in a 70 year old flathead block the chances are very slim a tap hasn’t been in every hole.
Yes remove the studs and apply permatex sealant on each stud. When torquing the heads to the proper pounds, be sure to follow the correct sequence. Start the engine and warm to operating temperature. Shut off and let it cool down and then retorque. Do this 3 times.
When all else fails use Snake Oil (Waterglass) ! https://www.supplyhouse.com/Lynn-Ma...t&gad_source=1&gclid=EAIaIQobChMIx7qmuee4hQMV
2nd Marty's advice on "waterglass". Was the go-to on repaired 426 Mopar Aluminum heads in the 70's. But drain the radiator only and flush with water. .
Be absolutely sure to torque the heads in the proper sequence. This is very important to prevent warping and poor gasket sealing. I use Permatex Teflon pipe dope on the threads that screw into the block. Do not use Teflon tape! You are over tightening the heads. Aluminum heads call for less torque than iron heads and must have special washers under the nuts. Recommended torque for aluminum heads is generally 40 to 45 ft lbs. Gaskets - I do not recommend copper or steel clad gaskets unless the heads and block have been milled for flatness. I use Best Gaskets brand Graf Tite style head gaskets on everything. Never a problem. They will seal over the bolt hole cracks. A dab of sealer over the crack won't hurt, either. If you still get a bit of a seep, it's time for the Bars Leaks.
Water Glass or Liquid Glass has been used in flat motors as long as I can remember that's 82 years worth ( Sodium Silicate ) we use to get it at the drug store
Quote "You are over tightening the heads. Aluminum heads call for less torque than iron heads and must have special washers under the nuts. Recommended torque for aluminum heads is generally 40 to 45 ft lbs." Then the info that came with the new heads must be wrong, as that is what Edelbrock said to torque them to. I do have the washers under the nuts.
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