Piston pins installation

[Brett James-McCall]

Help appreciated here from anyone with experience. I read through Tom Monroe's book where he explains that yu can install the piston pins into the rods by gently warming the rods, and then press the pins in before they cool down (generally a second or two). Either that it is pressing them in.

Well I guess I need some Red Bull as I have tried 4 and so far not managed to get any of them in before the rod has cooled again.

So question 1#. Any best practices for pressing the pins in

Question 2#. Anyone near me (J30 M25) who has access to a press?

Thanks
Brett

 

[Wayne M.]

When he says warm he means several hundred degrees F, 450-600 depending on the rod. There are special rod end heaters for this purpose. It has to be hot enough to expand the hole but not glowing yet. I have found that if you heat the rod end enough to insert the pin but dont put a pin in it the hole shrinks to be smaller than it was initially. If you press in the pins it is a good idea to knock off any sharp edges on the leading end of the pin. I use my crankshaft polisher. Be careful once the pin enters the back side of the piston. If there is any out of alignment the pin will scrape off some of the aluminium resulting it additional pin clearance on that side of the piston.

Electric Connecting Rod Heater

Wayne

 

[Ron Earp]

RE: Q#1 Best Practice - Have your machinist press them in.

 

[Randy V]

Pressed pins -

Pressed pins is a misnomer as they are not even pressed in at the factory where the engines are built. They must be, however, pressed apart if ever needed that way..

Yes the proper way to assemble is with a rod heater...
I've also used an acetylene torch with a rose-bud end on it.
Rod gets heated to dull red, pin is slipped into place and centered.

Assembly is left to air-cool - NEVER chill it with water etc..

I knew one fellow that ran himself ragged with a heat-gun and a pile of ice cubes. He did finally get one pin half-way through the rod before it synched up on him though...

 

[Jac Mac]

1.Practice on some old rods /pistons first so that you know what your in for-- Ive fitted thousands & I still have to psych myself up! You have about 10 secs max- probably less between where you stop heating the rod & have it safely installed. You will need to switch the phone off & lock the doors, the last thing you need at this time is a ''Honey can you...." (& we know your house has an extra priority on those at this time )

2. Have you had rods resized, checked brg clearances, checked for straight/twist, done piston deck height & valve clearance checks, drilled pistons for pin oilers & any other stuff you might want. Have you a means of fitting the pin to the required position so that you dont have to adjust after cool down.

3. If you are using oxy/acet to heat do so in natural light area to judge colour. I find you dont have to go as far as a dull red, but that depends largely in the light conditions you are working in.
Before heating each rod warm the piston slightly ( Keep pin as cold as possible ), lube pin bores, use marker pen to mark front etc from underside & remember 1234 rods have brg insert to rear/5678 have brg insert to front.(FORD)

Good Luck

 

[Cliff Beer]

I've had good luck with just touching the pin and the rod with a 45 degree chamfer on the mill - we're talking less than a thou, more like 1/10,000 - before heating with the rod end heater. This helps to center the pin in the rod bore and lessen the chance of taking off any material in the bore when starting the press.

 

[emiel]

Hello,I put the pins in a plastic bag and a night in the freezer.I take them out of the freezer only just before assembly.I warm the connecting rods gently with a torch and put the pin in place by hand.The "lock the doors and put out the phone" is maybe the best advice there is for this kind of work.Succes Emiel

 

[Keith]

I would have to agree with Ron that the lowest risk thing to do is to take them to a local automotive machine shop and let them do it.
However, it can be done with a 10 ton press, a hot plate and a freezer. You can support the big end of the rod on a wood block and set the small end on the hot plate set on high. When the element on the hot plate is "red hot" it will heat the rod end up but not get it hot enough to change the structure of the metal (I use the same hot plate for pressing on bearings, gears etc. it gets them hot but not hot enough to damage anything). You need to have your press set up and ready to go with a press mandrel to fit the pin and a backing block that fits the back side of the piston. As Jac Mac said do all the Right side then the Left side so you don't get the rods on backwards. Leave the pins in the freezer until the last second. It is very important to have the press all set up and do a dry run to make sure it all works prior pressing the pin in the first one.
Keith