As you have probably guessed, I need to fit my new pisons onto my rods. I've heard it's easy to do if you bake the rods and pistons in a grill, and freeze the pins. That you can just slide them in pretty much by hand liek that. Is this true? any dangers? Do you just get the pin in the middle...or is there some exact measurment it should be at?

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For no more than it costs, I'd have it done. If you absolutely HAVE to do it yourself, I believe that right smak in the middle is where you want it!

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Working on:
'84 Z28 LG4 305
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Block is in shop!

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Theres no measurement, just center it.
As for the baking and freezing thing... well... you dont need to bake the pistons, but I'm not sure the rod would expand enough from heating it in an oven, I have done it before and if it wasnt red hot, it never worked. I guess you can try...

 

If you don't have a Sunnen rod heater the next best thig to use is a propane torch. You heat the small end of the rod up as evenly as possible until it is kind of a light brown color if it gets purple its a little to hot. And then quickly push the pin in and center it. This is what machine shops without Sunnen rod heaters do. But last I checked it was only about 20 bucks to have it done. And if you stick a pin then you have to cold press it out and thats not fun. you run a big chance of distorting the piston if you have to do that. I've put pins in both ways and I've had to cold press them out The rod heaters are much nicer the heat the rod more evenly so there less chance of sticking a pin. Plus they have a stop that you set up so the pin is centerd you don't have to eye ball it you just push the pin in untill it stops. So my advice would be to take them to a machine shop and have them do it.

 

Pressing on piston pins is something I would definitely have a machine shop do. If you're off just several thousandths, you can accelerate cylinder wall wear due to the high loading on one wall.

If memory serves, the latest factory trick for press pins are to slightly off-set the pin to reduce piston slap on cold start up.

I'm a firm believer in doing ANYthing that I can myself, but installing press pins isn't one of them.

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

how'd you get the pistons off the rods? if i were going to do this at home instead of a freezer i'd take the less enviromently friendly route and use freon to cool the pins. back in the days on 25 dollars for 30 pounds of r12 we froze everything we could before we put it in. I'd take then to a machine shop, cost me about 30 dollars i tihnk last time i had it doen.

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-=ICON MOTORSPORTS=-
1st & 3rd

 

I think the environmentally friendly way is to use liquid nitrogen instead of freon.

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1984 Silver Z28, decked 383 cid 4 bolt, ARP Fasteners, 2 1/2" Cowl Induction Hood, 600 cfm Performer Carburetor, Torker II Intake, Performer RPM Heads, XE268H Cam, Magnum Roller Tip Rockers, MSD6AL Ignition, Blaster2 Coil, Recurved HEI Distributor, 700R4, TransGo SK, 2.73:1 Limited Slip Dana 44, Terminator Headers, Custom 3" TIG Welded Stainless Exhaust, Flo-Pro Twister Muffler, 4 Wheel Disc Brakes, Oil Cooler

 

I believe the offset pin is not in the installation of the pin, but in the location of the pin hole in the piston. I don't think that offsetting the pin from side to side would affect piston slap at all.

I just wonder how much it takes to accelerate the cylinder wall wear. I would think it would take a signifcant amount, like maybe .050 in. or something like that?

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Working on:
'84 Z28 LG4 305
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350
using primarily GMPP parts.
Block is in shop!

Awaiting results from all 8 ASE tests.

Starting to look like the Kicker poster child!

 

Take it to the shop and let them do it.

I worked in a machine shop for a while and if you don't get the pin in quickly and correctly you have to start over. The rod doesn't stay hot enough to slide the pin in for very long (just a couple of seconds)

Its money well spent to have someone else do it.

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ASE Mechanic/Machinist/Smog Tech

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