draining heat exchangers

[whoover]

Hello Jim,

Don't pour the old oil into your heating oil. I tried this with my workshop furnace by diluting one gallon of oil to four gallons of furnace oil. I was cleaning my oil burner once a week, it would not burn properly and stop igniting. It would always happen when the outside temperature was 20F of lower.

I save my old coolant to winterize my engines in the fall and a little bit goes into the pressure washer because my storage shed freezes.

Walt Hoover

[jim rosenthal]

I know. There is such a thing as a waste oil burner which is built for using waste engine oil and ATF, but my garage isn't big enough for it. And the garage where I keep my cars isn't mine, so it's not practical to put one there. It would be nice, though. No one makes a small waste oil burner that I've been able to find. Wish they did, I'd buy one.

[dsharp]

What is the preferred material for heat exchanger fasteners? Stainless or regular cad plated bolts?

[jim rosenthal]

Not sure what you mean. Mine, on Cummins B series engines, are held onto the engine by steel bolts, from Cummins, screwed through rubber and steel mounting pads. Can you clarify what you are asking about?

[Jammin']

The Detroit mechanic working on my 6-71's replaces the bolts with stainless when he removes them. He says he uses anti-seize on them, although I've heard of people using a marine grease with no metallic content out of concern for electrolysis. I don't know if that's a legitimate concern. I currently have stainless in the port exchanger and grade 8 in the starboard. We'll see what breaks.

[dsharp]

I was thinking more about the Detroit style. I think they’re 5/16 bolts and it seems like at least 1 will break if the previous mechanic failed to use an anti seize product. Some of the stainless today is pretty soft.

[Finalee]

Avoid the guess work and use what Detroit sells.

[racclarkson@gmail.com]

Avoid the guess work and use what Detroit sells.

Ditto. Beware of SS galling. Note the heat often generated from just hand ratcheting.

I like to treat steel bolt heads with phosphoric acid and leave overnight. They will have a protective coating on them plus be etched and ready to accept paint.