Junk yard dog pins won't fit
05-03-2014, 03:49 PM
#1
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Junk yard dog pins won't fit I have a set of wiseco junk yard dog pistons for my 6l. The pins won't fit in my stock full float rods or my 6.100 callies rods that are made for stock pin. But the stock pin fits nicely inside both sets of rods. Has anybody had this happen? I can't call wiseco till Monday.
05-04-2014, 07:47 AM
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The stock wrist pin fits in the callies rod. I took one out of the stock piston rod assy and tried it. The stock pin is about .0015 smaller than the new wiseco pins. Funny thing is the stock pins are about .030 thicker walled than the wiseco's. The wiseco pins are .944, that's what the spec sheet says and that's what I measured too. Stock pins are actually .943 mine are just shy of that but it had 140,000miles.
05-04-2014, 04:20 PM
#6
I just recently ran into this on a GEN I 400 engine that I built. The new replacement cast pistons came with pins that measured 0.0005" larger than the original pins. In my case this was a press fit situation where I believe the idea is to make sure there is adecuate press(interference fit) after honing the small end of the rod to remove any scratches or galling from pressing out the old pin. My machinist and I measured everything and the small ends of the rods were still fine. Instead of honing the pin bore of the new pistons which had a pin clearance of 0.00035", we polished and reused the original pins which were not only 20 grams lighter but put the piston/pin clearance right at the sweet spot of 0.00085".
In your case the piston manufacturer probably figures that you're gonna take your old rods to the machine shop and rehone/size the small end bushings to fit the new pins. If your small end bushings look ugly or galled then this is probably the best bet. If they look fine perhaps your stock pins could work as long as they fit in the piston (side to side) in between the retaining clips.
In your case the piston manufacturer probably figures that you're gonna take your old rods to the machine shop and rehone/size the small end bushings to fit the new pins. If your small end bushings look ugly or galled then this is probably the best bet. If they look fine perhaps your stock pins could work as long as they fit in the piston (side to side) in between the retaining clips.
