sliding pistons in the block with auto trans fluid

OK, I'll warn everyone now. I'm getting ready to start putting together my first engine since the 283 I built 30 years ago, so stand by for a slew of dumb questions. I'm proud to say that I still have have that old motor pounding away in my '36 sedan, so at least I am building on some degree of past success.

Anyway, I'm going to build not one but two flatheads, a 59A and 8BA. I've been going over all of the flathead books I've collected these past many years getting ideas and tips. I came across a note I made to myself apparently after watching an episode of Hot Rod TV. It gives the tip that when installing the pistons use auto transmission fluid as it will aid in the break in of the rings. I grew up with the notion of liberal amounts of 30 wt. used when filling the big holes and that's what all the books have. Anyone got any wisdom about this obscure tip I found?! Thanks in advance.

 

not sure about flatheads in particular, but on any engine I'm ***embling, I wipe down the bores with a paper towel soaked with atf, repeat until the paper towel comes out mostly clean (rather than black or gray). Then I put a liberal dose of engine oil on the rings and skirt and pin before installing the pistons

 

Have heard of using ATF, Marvel Mystery Oil, common oil.

 

Yea ATF for cleaning like squirrel said.

 

call flathead jack and ask what he uses when he ***embles one.

 

After the bores were clean, I used 2 stroke oil to install the pistons. That way it burns off when you fire the car and the rings can seat.

 

heh....most old engines don't seem to have any trouble burning regular engine oil....

 

I was told by my old and trusted machinest to use ATF, as it has a detergent that keeps the rings from gumming up. Like they would with burnt oil. Don't know how much truth there is to it, but I've never had a problem with rings not seating.
Another trick I've always done is to use a can of GM's EOS (Engine Oil Supliment). Just pour it over the cam before closing the engine up. The stuff is as thick as honey and sticks to everything it touches.

 

Thanks for the responses, gentlemen. It appears that no harm will be done using ATF in the ***embly and that there may be some advantages. So, maybe there is some validity to the tip.

 

I have a friend that has been rebuilding engine for years ( 20+). He told me that ATF works best