rod bearing install

[Sleeper]

So, when people are installing bearings with the engine in the car, are you cleaning the connecting rod bearing surface? Whenever I've built motors, I've ensured that the surface behind the bearing was meticulously clean. It seems like it would be very difficult to clean the rod, install the bearing, and **** it without contaminating the rod surface with oil. Is it unimportant to keep the oil from behind the bearing? I'm just concerned about longevity. Anyone who knows what they're talking about(not "I did this 10,000 miles ago and it's fine...), lemme know. Thanks!

 

[kickeralpine]

i just did mine and what i did was pull the pan the night before and let all oil drip out didnt have stuff dripping in my face and keeps rod surface dry hope that helps and yes i really clean the rod surface i think it is inportant to do iv done many of these engines

 

[SHO#7]

I did this 10,000 miles ago... oh I mean.

When I did the three cars that I have done. I used assly **** instead of oil. I was very careful to keep things clean and went through a ton of soft cloth rags. When I pulled the rod caps off, and pulled the bearings out, I cleaned everything down with brake cleaner. Wiped my hands down, then put the assly **** on the inside of the bearing. Locked the top bearing in the rod, and slid it down on top of crank. I then cleaned the cap off with brake clean, wiped my hands down again. Installed the bearing in the cap, and applied some assly **** to the inside surface. Re-installed the cap to the rod and did the two stage torque. The specs are around here if you search. I do not remember off the top of my head. Like 25 and 35 or something close to that.

It is not a very painful job. Just allow enough time to do it. And all should go smooth.

Mike

 

[TankII]

Assembly ****, graphite/synthetic grease, or 20W50 oil all work well.

TankII

 

[Rockledge]

Doesn't oil get behind the bearing sooner or later anyway?

 

[Sleeper]

nope.

 

[Off Road SHO]

nope.

Well, it sorta does, but not the way you think it does. Since the oil is coming out of the crank, it only is pressurized during its' passage from the crank hole to the edge of the bearing, where it is then flung off in all directions. Part of the oil goes up throgh the rod to the weep hole near the wrist pin. This oil hits the cylinder wall and piston skirt.

However, oil, like any liquid will "wick" into the space between the bearing and the rod. When I say space, it's not like it's a measurable space that you have to worry about. Most of the discoloration you see on the rod surface is caused by vapor deposits, which can be corrosive.

What you absolutely, positively don't want is anything in that space that will 1) Take up space while the rod is being torqued down, and 2) Anything that will cause a "deformation" of the bearing. That deformed part will not get the cushion of oil that the rest of the bearing gets. Very bad.

While cleaning everything with brake kleen might be a little overkill, I would never complain about someone being too clean when it comes to bearings in a high revving motor like the SHO.

Tom

 

[DHMag]

to follow up with Tom:

some will suggest using fine steel wool on the bearing to "prep" it for use. while mainly this is meant for race motors, its not necessary on the Yamaha engine. if youre concerned about sterilization. buy a box of latex gloves and change them with every bearing half. my idea of being sterile is spraying my bare hands with carb cleaner or brake cleaner before im about to install the new bearing.

ive done 5 rod bearing jobs on 5 SHOs. all i did was remove the cap, push the rod/piston up into the cylinder. sprayed carb cleaner on a blue shop towel, and wiped the crank journal. on the cap, i sprayed with carb cleaner and let sit while i was installing the upper bearing. then, using your preferred assembly ****, coat the face of the upper bearing and top half of the crank journal, then pull the rod back onto the crank. install the lower bearing, apply light coat of assembly **** to crank and bearing, and fit it back together. upon completion, i treat the car just like after an oil change. i disconnect the DIS module and crank the engine until the RED oil light goes off. reconnect DIS, start it up.

 

[Rockledge]

However, oil, like any liquid will "wick" into the space between the bearing and the rod. When I say space, it's not like it's a measurable space that you have to worry about.

That's what I was wondering.

 

[FrankenSho]

if youre concerned about sterilization. buy a box of latex gloves and change them with every bearing half.

thats what i was going to suggest.