Piston Wrist pin Cap question on Force 150hp 1992

[daffidad]

I have to replace piston 2. I have an original equipment replacement. It comes with the wrist pin, needles and caps that center the wrist pin from inside the piston skirt. The old one is the same way. Is that pressed on, Heated and then installed? I tried to push out the old one, NOT HAPPENIN at this point?

 

[Frank Acampora]

Re: Piston Wrist pin Cap question on Force 150hp 1992

They are pressed on in a medium interference fit. Some are really tight. You need a press with a 6 ton bottle jack to remove them. You also need a special tool to space the keepers so they don't squeeze the needles both for removal (if you intend to re-use) and installation. This will dent the keepers in addition to stopping the needles from rolling. HOWEVER: If you buy a Wiseco piston, the wrist pin is retained by circlips, loose spacers and new needles are sold separately for about 15 bucks, but the piston comes complete with rings and wrist pin. Can't beat that with a stick!

The tool spaces the keepers at about .028 for removal and about .030 for installation so you might be able to jerry-rig something.

Later I will hunt it up and give the actual dimensions.

 

[pnwboat]

Re: Piston Wrist pin Cap question on Force 150hp 1992

You need a lot of pressure. I have a two ton mechanical press and I can barely push them out with it. When you press the new ring spacer/keeper on, there is a special spacer tool needed to keep you from crushing or binding up the needle bearings. Looks kind of like a fork with two prongs. Without it, it's pretty hard to get everything centered and not bound up. You also need a jig curved like the piston to hold it. I've made one out of a piece of oak. If you lay the piston on a flat surface, it's difficult to press the pin in while holding the piston in place.

I try to avoid using the "pressed pin" pistons. I usually use the forged units which generally have the "floating wrist pins". The pins can be installed by hand, and use a wrist pin keeper that keeps the wrist pin in place.

 

[jerryjerry05]

Re: Piston Wrist pin Cap question on Force 150hp 1992

Hey FRANK!!! What's up with the jerry-rig stuff Have a good day!!!!J

 

[Frank Acampora]

Re: Piston Wrist pin Cap question on Force 150hp 1992

Yeah! I was almost going to include an apology but then figured "What the hey. You deserve a little dissing!" Figured I would get your dander up. LOL. Hey, I could have used the politically incorrect racial reference, but I am not like that. Live and let live!

Feel better if I change it to "Jury-rigged?

 

[daffidad]

Re: Piston Wrist pin Cap question on Force 150hp 1992

Wow thanks for the info. It briefly crossed my mind to convert my log splitter into a press, BUT I thought better of it. an auto/racing shop was recommended by a friend so I took it up last night and he is giving it the workover. He commented who the heck came up with this wrist pin placement design, it's awful!! So my next step if he fails is a wieseco piston! Thanks for your input and I will post how it turns out!
Tom

 

[daffidad]

Re;bearing centering pin

Re;bearing centering pin

help. i cant figure out how to start a new thread.

should the centering pins be somewhat flattened or just rounded enough to fit into the bearing casing hole.

 

[Frank Acampora]

Re: Piston Wrist pin Cap question on Force 150hp 1992

First, in order to post, you must join the forum. Then, when you enter Chrysler/Force forum, near the top of the page you will see in blue "create new post"

At any rate, some pins are slightly rounded, others are a bit more sharp edged. You must "feel" around a bit to get them in the holes in the bearing shells and sometimes it can get frustrating. You will do best by starting with the topmost one and working down. That way, the crank will always be at a slight angle and each pin will be easier to feel.

 

[daffidad]

Re: Piston Wrist pin Cap question on Force 150hp 1992

Thank you Frank I appreciate your help!
Tom

 

[*wrenchead*]

Re: Piston Wrist pin Cap question on Force 150hp 1992

They are pressed on in a medium interference fit. Some are really tight. You need a press with a 6 ton bottle jack to remove them. You also need a special tool to space the keepers so they don't squeeze the needles both for removal (if you intend to re-use) and installation. This will dent the keepers in addition to stopping the needles from rolling. HOWEVER: If you buy a Wiseco piston, the wrist pin is retained by circlips, loose spacers and new needles are sold separately for about 15 bucks, but the piston comes complete with rings and wrist pin. Can't beat that with a stick!

The tool spaces the keepers at about .028 for removal and about .030 for installation so you might be able to jerry-rig something.

Later I will hunt it up and give the actual dimensions.

Hi Frank,
Do you have the dimensions handy to make the spacer tool.
Should have bought the Wiseco piston but the Seirra was the only one in stock at the time at iboat.

Thanks for all your guidance.
*wrenchead*

 

[Frank Acampora]

Re: Piston Wrist pin Cap question on Force 150hp 1992

I will see if I can find my tool ( Not that one, I always know where it is) and post a photo

 

[wickware]

Re: Piston Wrist pin Cap question on Force 150hp 1992

Daffidad,

I sent you a private message (info showing in the upper right corner at the start of messages) related to your log splitter. Thanks! JOW

 

[*wrenchead*]

Re: Piston Wrist pin Cap question on Force 150hp 1992

I will see if I can find my tool ( Not that one, I always know where it is) and post a photo

Hey Frank,
I used a 7/8" open ended wrench for removal and installation.
Just finding one with a jaw thickness of between 0.295" and 0.310" was the trick. Found one in a flexhead/open end combo that was perfect.
Now, I have another issue that has kept me up for the past three nights.
After doing the vasoline trick with the 16 bearings for the third time I have a big question.
Should the cages be able to freely rotate all the way around the journal?
The only example of a force con rod I have is the adjacent cylinder and it can completely rotate.
The two manuals I have state the needles should be free and have no binding issues when you spin the crank by hand.
The cracked caps are in perfect alignment, but I have just snugged down the cap screws. Didn't want to possibly wreck a good con rod in the process. Could tightening up the screws to spec. help the rotation?
Is there a wrong way to place the cages?
Is the cage rotation important to the journal life?
Am I being too particular?
After an overheat on the top cylinder due to the impeller, I have rebuilt the pump and re-sealed the lower end, replaced the starter and now the broken top ring on cylinder #1 this '89 150hp Force has had me loose many hours of sleep. Having decades of experience in automotive rebuilding, this only my second marine outboard and this one has been an experience.
This project has been going on for 2 seasons.
Any opinions from the Force experts on the rod bearings?
Regards,
*wrenchead*

 

[Frank Acampora]

Re: Piston Wrist pin Cap question on Force 150hp 1992

If you torque down the cap bolts without aligning the caps there is a possibility of damaging the rod.

Cracked cap technology hardens the rod then it is "staked" at the Vee notch. The cap breaks off rather cleanly. However, no two rods break the same and the cap must be aligned so the rollers pass smoothly over the crack. Torquing the bolts with the cap misaligned will mash the irregular ends together and the cap will no longer be alignable. Thus, on Force engines, two diagonal sides above and below the bolts are ground smooth before breaking. You snug the bolts and pass a pencil point, dental pick, sharp screwdriver , pointed welding rod, or other tool over the crack. If it passes smoothly, you are done--Torque the bolts. If it bounces or catches, loosen the bolts very slightly and tap the cap to center it. Be fussy here.

When some of these caps break they leave a small gap at the outside edge in the joint. (hey! No one is perfect! LOL) Do not mistake this gap for misalignment.

Vaseline or grease is quite a bit thicker than oil. It will hinder rotation of the bearings and cages. However, when you turn the flywheel by hand, you should NOT feel any catching or tightness as the crank passes through its full rotation. After everything is assembled, squirt some TCW oil into the bearing and around the rod and crankpin. And, don't run the engine fast until enough fuel/oil mix has been burned to wash out the bearing.

 

[*wrenchead*]

Re: Piston Wrist pin Cap question on Force 150hp 1992

Wow.
Thanks for the quick reply.
The caps are definitely in alignment. The two polished areas on the sides of the rods have no edge that can be noticed with the dental pick inspection.
There is no binding anywhere of the crank and rods when turning the flywheel.
I should be able to torque the bolts without any damage to the rod.
But I don't think tightening the bolts will change the gap; if anything it will be tighter.
I guess my big issue is that I can not turn the cage a full circle on this rod like I can on cylinder #2.
I have been using a scratch awl through the oil slot in the rod cap (being carefull not to scratch the cage surface and create a burr) to rotate the complete cage around. There are areas that require more force than I am willing to apply in case I slip off the cage and mark it. In fact while trying to move the cage I ended up move the crank instead, so I am thinking the cage may not free up later when running. I maybe wrong.
What would you suggest?
Button it up and and break it in gently and hope for the best?
(Also great idea on trying to wash out some of the grease with TCW.)
Or take it apart one more time and carefully inspect these cages to see what may be be hindering their rotation?
Am I chasing a goose here?.
Just too much time and effort in it now to risk a ruined crank journal.

Regards.