| Author | Message | ||
     Bomber |
(cross posted from the KV for greater traffic I'm in the middle of my 1250 kit install, and have a question for the experts -- the piston pins supplied with the pistons (CP brand) are tight as they can be in the bore -- I received the pistons in their original packaging, with the pins slipped into the bore on one side of the pistion (which makes sense) I cannot slide the pin any further into the piston by hand (it takes a pretty good wailing with a leather-faced hammer to budge it) in previous engine builds (non HD), when confronted with this situation, I'd pop the piston/pin assembly into the toaster oven for a bit at about 275 degrees -- so, does the same practice hold for a sporty mill? thanks for the backup, all! | ||
| Aaomy |
hey bomber,, never heard of a toaster oven piston heater before. guess i should have kept the one i just gave away.. most instruction i have seen say to heat the pistons to help install the pins.. one place i read said to wrap the pistons in towels soaked in hot water.. personally i just use my heat gun to warm them up toasty like and press.. if perswaysion is needed be careful of too much lateral load on your rods and bearings... hope this helps some.. aaron | ||
| Bake |
Sounds tight but definately no expert on HD engines, you could freeze the pins for that extra bit of clearance. | ||
| Firemanjim |
And a little tap with brass drift gets em moving along-- | ||
| Xldevil |
Hi. I've solved that problem by freezing the pin and slowly heating the piston with a heat gun. The pin slipped right in,without any force. Never ever tap a piston pin into the piston! The con rod lower bearings will thank you for that. Ralph  | ||
| Oldog |
Ralph is that Assembley lube or did you slash your wrist in the process?  Correct me if I am wrong is there not a tool made to pull / push the pin in I take it a bolt and nut are NOT the way to go here | ||
| Phat_j |
yes freazing the pin is the way to go if necissary, heating the piston is accepted also, no a hammer is definatly not recomended, although many still do it IF you are supporting the backside... but i still dont condone this.... yes there is a piston pin installer/ remover tool you can get, or make your own.... (all thread and a couple washers properly sized of course) and last but not least, did you measure the fit of the pin to the con rod? | ||
| Xldevil |
 Fortunately it is assembly lube. For pulling the old pins out, I made me a simple tool.  Ralph | ||
| Bomber |
thanks fellas -- in the spirit of science, I tried BOTH the toaster over (which is also good for baking paint on smaller parts) and the heat gun -- both worked aces now, convincing the pin retaining rings into their grooves ;-} kewl lookin tool in the Service Manual thanks also to rocket who responded in teh KV! | ||
| Oldog |
and last but not least, did you measure the fit of the pin to the con rod? The rod end is bushed for size are the bushings available in different sizes? } | ||
| Bomber |
Dawg -- not sure about the availability of different sizes, but the SM has a lengthy procuedure for honing the bushing, if necessary -- both the heat gun and the toaster over worked great, btw -- though I like the heat gun better -- specially since it's purchase was originally made for house paint stripping -- plowshear into swords, and all that Phat -- it fit about the same as the sotcker (which showed no signs of wear at all) according to my highly calibrated thumb ;-} X1 -- great tool! I gotta make me one of those! | ||
| Phat_j |
yup, diff sizes, and then honed for a perfect fit....... that is if i were building your motor, lol | ||
| Bomber |
Phat -- I'm sure you'd do a better job than I am, but then I wouldn't be having quite as much fun! gotta get that thumb re-calibrated . . . . |
