All Day Dan

My Feedback: (5)

I am trying to remove the connecting rod bearings in my Brison 3.2 using the gear pullers available in the auto supply stores and a couple of fixtures that fit the bearings I had a machine shop make up for me. I am using the pullers to push the bearings out and to push them in. It turns out the gear pullers are very crudely made and sloppy. I have ground down their grips to better match what I need but I can not get them to give me a good fit and a decent alignment. Is there a better way to do this? Thanks, Dan.

Truckracer

My Feedback: (19)

Dan, I just use a U-joint or small arbor press. These are available from any of the econo tool stores at a very reasonable price and are more than adequate for our use. I use 1/4" and 3/8" drive sockets of the proper size to either support the rod OD or to push on the bearing race as necessary. In some cases, like you I have made special tooling when needed. Flat aluminum or steel strips can also support the rod. The cupped bearings as used in the Brison engines push out / in very easy and the press helps to keep everything square. I use a tiny bit of red LocTite on the bearings when installing. You could even use a drill press for the Brison rod bearings. The hardest thing about replacing Brison rod bearings is finding bearings with the proper clearances on the wrist pin or crank pin.

I've had one of these presses for years and found it extremely valuable when I flew helis. Helped to assemble bearing blocks that were once common. Attached is a link to some common presses. Smaller ones are available if you look around some.



http://www.northerntool.com/shop/too...+arbor-presses

All Day Dan

My Feedback: (5)

Thanks Truck. My brain must be on another planet. I should have thought of that. I'll be going down to my local Harbor Freight and pick one up tomorrow. Dan
http://www.harborfreight.com/catalog...on+arbor+press

Truckracer

My Feedback: (19)

That will do the job!

w8ye

My Feedback: (16)

I have one of those arbor presses that I've used on model airplane engines for 20 years. Prior to that I used one at work.

All Day Dan

My Feedback: (5)

OK. For $32 the ½ ton arbor press worked perfectly. Those little plungers I had helped out a lot keeping everything lined up. I also used the plate that retained the connecting rod in position with a clearance hole underneath it to push out the bearing. The openings in the plate that came with the press were not the right size. Thanks guys for your help. Dan.

Truckracer

My Feedback: (19)

Its always nice to get a new toy and have it work as expected!

Dan, I know you're a Brison man but some people may not know this. On Brison engines, the bearings are not always centered front to back in the rod. They press the lower bearing in until it centers the rod in the bore of the cylinder when it is assembled to the crank. Then the upper bearing is installed until it is centered on the wristpin in the piston. Sometimes the bearings are fairly well centered, sometimes not. None of my Brison engines have ever been assembled quite the same as they came from the factory. At first I thought it was sloppy workmanship then realized they did what they did for a reason.

All Day Dan

My Feedback: (5)

Truck, you are right. In fact, Garry Allison used different width wrist pin spacers to avoid some kind of interference with the crankshaft counter balance. Arthur Leung, the designer of the engine and the person who provided Garry with the parts, is not too sure what Garry was trying to achieve. I have found that centering the top and bottom bearings in the connecting rod and using whatever spaces were in the engine worked out. One of these days, I’ll ask Bill Jensen about it. Dan.

Truckracer

My Feedback: (19)

None of my engines have had the spacers but I have heard about them. Where are you sourcing your rod bearings? The last ones I bought came from *bay sources, were excellent German and Swiss brands and worked perfectly with proper clearances.... and they were cheap, really cheap!

Regarding Brison, I find all the variations in cases, internals, etc. over the life of their production to be quite interesting. Dang good engines though

All Day Dan

My Feedback: (5)

Truck, there are so many counterfeit and just pure junk bearings out there I am going to look around locally for a reputable dealer of top of the line items like Timken or Fanfir. The bottom connecting rod bearings are failing and I am going to start a program of preventive maintenance and replace them on a regular basis. Sometimes they just start sounding loose and sometimes they seize with horrible consequences. $5 to $10 each would not be unreasonable considering the expense of shipping the engine off to someone else to do the repair. Dan.

Truckracer

My Feedback: (19)

I've used INA, SKF, FAG and a few other brands. INA seems to be a very good brand for the cupped rod bearings. This is a German company ( I think ) and their products come from various European locations. If you can find them, Swiss WIB bearings are excellent.

The main problem I have finding quality bearings is sourcing them in small quantities. Most of the high quality companies, especially the American companies, will only sell to companies and in large quantity. They really don't want to sell in small quantities. I gave up trying to find the proper bearings in the proper clearances. Trying to find anything from a local company is nearly impossible .... at least in my area. You ask for a specific brand with say a Cx clearance for a crank bearing and they just give you that Deer in the headlights .... 100 mile stare, then quote some incredible price to get you to leave the store. So I cooperate and leave! I seem to have very good luck with the on line, commercial vendors as they seem to really care about your business.

I've never been very satisfied with hobby outlets for bearings. Most sell just average quality, mostly Chinese products. OK in many cases but not for something you really care about. And this goes way back through my pylon racing, glo engine days. Frankly, our gas engines are really quite easy on bearings so my re-builds are usually limited to something I bought used.

All Day Dan

My Feedback: (5)

Truck, the local office of Applied Industrial Technology had access to the INA versions of the HK1012 and HK1212. They had to have them them shipped in from some where so it will take a week. Hopefully I'll get some more lifetime out of this better brand. They were around $5 or $6. A few bucks more than the no name versions but well worth it considering what a failure can cause. Dan.

captinjohn

You can use a good 4 inch vise to press parts out & back together again....with the right tooling used............

Bass1

Hey guys, I've got an overheating problem with one of my Brison 3.2 engines and suspect it's a bearing issue from a previous crash. Truck racer and CapnJohn suggest the use of a drill press or 4 inch vise for removal and replacement. I have both of those. Can you share a technique and what else to use for this procedure with my available tools?

All Day Dan

My Feedback: (5)

When bearings go bad, you can usually hear it or feel it way before they overheat anything. What makes you think your engine is overheating and why do you feel that it’s the bearings causing it? Dan.