Sealed Power h405 new pistons. eBay purchase. pins are stuck & I soaked one of em in the solvent tank for a day or so & still stuck. should I tap it with something or soak it in something else? thank you for your time.

Try heating them in the oven.

Will do. EDIT how hot? MORE EDIT Stump you're the man! it took the oven several minutes to get up to 300 & I took it out to check it after several minutes as I dont want to damage it & to my surprise it came out, so I stuck the rest of em (ex for the one still in the solvent tank) in there. EVEN MORE EDIT Done! (7 of em) alum sure must expand way faster (or a greater amt) than steel. That was WAY too easy.

Used that trick before and it makes removing and installing pins easy.

Actually both. :-)

Just make sure with light oil on them that they are free in the pistons, they might need a light honing.

Most aluminum alloys expand 8 times more than steel at the same temps.

Rallye I will do. Cab yes it was no time at all in there (I was worried that 300 was to hot) so I pulled the one out fairly quick & it was free.

You can actually expand a piston by holding it in your hands too much and warming it up! I found that out about 40 years ago working on snowmobile engines. You can also " compress" a piston with your hands when measuring if you squeeze it hard.If you put a 4" mic on a piston skirt, squeeze it with your hand, the mic will fall right off...

Alright let me do this, I will clean the remaining piston that is resting in the solvent tank & warm it up with my hands & see what transpires. The ladies' say my hands are magic so lets see if that works across the board

Oh jeez.....

double R, "be vewy, vewy caful !" [in my best "fudd" voice ] you might be setting yourself up to be the next big news report on tv with several "ladies" on the accusing end for you doing "naughty things" !

Understood, I'm always on my best behavior.

I was told by all the ladies I handled that they love every part of my body, hands and all
It is absolutely amazing what the ladies will do for you if you treat them right and take care of their needs first, like all gentleman are taught to do

Merry Christmas and a happy and prosperous New Year to all on here

This is funny.

Mr. Cab, I have figured out where your instructor messed up. He was using the values for VOLUMETRIC thermal expansion. But unless you are trying to figure out whether the aluminum will float, it has little value to know that. What we're trying to determine is how much the Linear coefficient of thermal expansion differs between steel and aluminum.

Aluminum coefficient of linear thermal expansion is 21 - 24 relative units.
Steel coefficient of linear thermal expansion is 11 - 12.5 relative units.

So the correct rule-of-thumb multiplier is 2.
Aluminum expands in length at about 2 times the rate of steel for a given temperature increase.

I have noticed on new stock replacement, pressed pin type pistons, quite a few pins need a little rap on the pin to get it to come out. I am inclined to believe that millions of such pistons have been installed without any additional pin fitting.
I haven't ever heard of needing 300 degrees F to get the pin to slide out. Usually, hot water from the tap is all that's necessary.

R.

Yes I was worried that I set it too high & luckily I went back in the oven pretty quick. Dog what I am gonna do is put my healing hands on it & see if that does the trick (it usually does!) then if not then hot water then the oven again at maybe 150.

I just put my healing hands on it & in short order it came right out (I couldn't believe it). thanks guys!