INSTALLING ENGINE BEARINGS

[chunk t]

I'm looking for your preferances for installing engine bearings?

Do youi like to -

1. load both bearings in the front plate first then press in the crank?

or

2. install the main bearing to the crank and the support bearing to the front plate, before pressing the crank in?

I typically use method #2.

chunk t

 

[RaceCraftBearings]

The correct way would be to install the main bearing on the crank, then slide the crank into place making sure the main bearing is fully seated. Support the assembly and slip the small bearing on being sure it is fully seated. Now install the flywheel collet, flywheel and flex hex and snug it up for the cooling process. Squirt some tranny fluid into the bearings to help cool, keeping the retainer from to much of the heat that may be left in the case. Spin the crank a few revs to see how evrything feels. After the assembly cools off tighten the flex hex and reassemble the motor.

Side note: When installing polymide (plastic) retained bearings it is imparative not to be in a rush to install the new bearings just after heating the case to get the old bearings out. You must wait until the majority of the heat has disapated otherwise you stand a chance of melting the retainer and ruining the bearings. This is the main reason I squirt tranny fluid into the bearing I install helping to safeguard the retainer from to much heat.

Ron

 

[chunk t]

Ron,

I always use heat as a last resort to remove a really stubborn bearing. I've found more often than not, evenly distributed pressure will slide the bearing. If you've left the case sitting around a day or two, do you make a prictice of reheating the case before installing the bearings? I've always left the case cold.

chunk t

 

[Jim Allen]

Ron,

I always use heat as a last resort to remove a really stubborn bearing. I've found more often than not, evenly distributed pressure will slide the bearing. If you've left the case sitting around a day or two, do you make a prictice of reheating the case before installing the bearings? I've always left the case cold.

chunk t

Do as Ron has suggested! Removing or inserting bearings, that have an interference fit, in any type of an aluminum housing MUST be done with heat. If done without heating the housing first, the interference fit will be lost & the bearings outer race will spin in the housing. Locktite should not be used, because it is intended for steel to steel applications.

Jim

 

[RaceCraftBearings]

Do as Ron has suggested! Removing or inserting bearings, that have an interference fit, in any type of an aluminum housing MUST be done with heat. If done without heating the housing first, the interference fit will be lost & the bearings outer race will spin in the housing. Locktite should not be used, because it is intended for steel to steel applications.

Jim

Boy Howdy Jim, I have seen an OPS that the owner pressed them in and out on over several bearing changes. After that they would fall in and out of the housing, not a pretty picture!

Heat used properly will not hurt a thing..........

 

[ids987]

Do as Ron has suggested! Removing or inserting bearings, that have an interference fit, in any type of an aluminum housing MUST be done with heat. If done without heating the housing first, the interference fit will be lost & the bearings outer race will spin in the housing. Locktite should not be used, because it is intended for steel to steel applications.

Jim

Jim,

I've used green Loctite before - with some success. I think it's acrylic based. Just wondering if you have any thoughts on this please, or whether you can recommend anything else. I've just ordered new bearings from Boca, with a seal on the front bearing - to try and salvage an old Picco 67 EXR with shot bearing mounts. The green Loctite held before (where normal Loctite failed), but the air leak was too bad with standard bearings (hence the sealed front bearing). I'd appreciate any thoughts if you or anyone knows of anything better than green Loctite to hold the bearings in though (preferably removable !).

Thanks in Anticipation

 

[Don Templeton]

I can't think of anything as strong and heat resistant as Permatex sleeve retainer from NAPA wich is probably the same as green loctite. (with a reasonable fit to the bearings) 3000psi shear and 400 degrees F

I use it to attach the flex cable to the stub shaft.

Don

 

[Jim Allen]

Do as Ron has suggested! Removing or inserting bearings, that have an interference fit, in any type of an aluminum housing MUST be done with heat. If done without heating the housing first, the interference fit will be lost & the bearings outer race will spin in the housing. Locktite should not be used, because it is intended for steel to steel applications.

Jim

Jim,

I've used green Loctite before - with some success. I think it's acrylic based. Just wondering if you have any thoughts on this please, or whether you can recommend anything else. I've just ordered new bearings from Boca, with a seal on the front bearing - to try and salvage an old Picco 67 EXR with shot bearing mounts. The green Loctite held before (where normal Loctite failed), but the air leak was too bad with standard bearings (hence the sealed front bearing). I'd appreciate any thoughts if you or anyone knows of anything better than green Loctite to hold the bearings in though (preferably removable !).

Thanks in Anticipation

Ian,

There are several green colored Loctite methacrylate anaerobic cylindrical retaining products. Loctite #609 is used on dissimilar metals with gap distances as large as .005 in & has a shear strength of 2,300 lb/si. Loctite #648 is used on similiar metals with gap distance as large as .005 in & has a shear strength of 3,600 lb/si. Loctite #680 is used on similiar metals with a gap distance as large as .015 in & has a shear strength of 3,500 lb/si. All can be cured in approximately one hour if heated to 100 deg f. All can be easily removed if heated to 480 deg f. These products should be used with recommended degreasers & primers, but acetone will work also.

Keep in mind that the polyamide plastic cages will stand 250 deg f for short periods of time, therefore after removal, they should not be used again.

Jim

 

[ids987]

Thanks Jim and Don for your help,

The "green" Loctite I used last time was #603. My failed attempts were with standard, and also #641 aka Bearing Fit.

From your comments Jim, I thought I might try #609 this time - as it's for dissimilar metals, and the gap-filling, and I believe shear-strength should be adequate, but I don't think it's available in the UK. I found it on Loctite's US website area, but not UK area.

I'll have a look at the others, and Permatex as well. Otherwise I may try #603 this time, as it seemed to work last time. I didn't try it for long though - due to poor running caused by the air leak. Loctite's data on this product is a bit sparse.

Ian

 

[ids987]

Ian i use loctite # 609 at work here in Australia

let me know if you want a bottle i can post it to you

just pay postage

p.s i used #609 to hold bearings in an old k&b that had been mistreated

with no issues at all the guy brought the engine back to me a year later

for a new set of bearings and the was no sign of rotation in the housing

Greg,

Thank you. I just sent you an email. Please let me know.

Ian

 

[dannyual767]

This is great information for me as well. I have an old but little used OPS .65 that I bought brand new when I was a senior in high school in 1979-80.

I replaced the bad bearings for the first time about 3 yrs ago with Boca Bearings. I heated the aluminum cases and the old bearings slipped right out. Unfortunately, the new bearings pretty much slip right back in even without heat to the case . I thought that I read on this or another website that OPS cases can sometimes need replacement when the bearings go bad. Maybe one of these green Locktites will work for me :unsure: ?

 

[Ronald van Essen]

No one is seem to mention the special bearing tool from Novarossi for their engines.

Any one can give their findings on that one?

Ronald.

 

[Don Templeton]

This is great information for me as well. I have an old but little used OPS .65 that I bought brand new when I was a senior in high school in 1979-80.

I replaced the bad bearings for the first time about 3 yrs ago with Boca Bearings. I heated the aluminum cases and the old bearings slipped right out. Unfortunately, the new bearings pretty much slip right back in even without heat to the case . I thought that I read on this or another website that OPS cases can sometimes need replacement when the bearings go bad. Maybe one of these green Locktites will work for me :unsure: ?

Danny,

All I can tell you is that John Ackerman glued in my bearings many times on an older OPS 65 and it held up very well during some very hard racing. I have no idea what he used but he's on this forum and you might send him a message and ask. Or try on RCBOATS forum.

Don

 

[RaceCraftBearings]

This is great information for me as well. I have an old but little used OPS .65 that I bought brand new when I was a senior in high school in 1979-80.

I replaced the bad bearings for the first time about 3 yrs ago with Boca Bearings. I heated the aluminum cases and the old bearings slipped right out. Unfortunately, the new bearings pretty much slip right back in even without heat to the case . I thought that I read on this or another website that OPS cases can sometimes need replacement when the bearings go bad. Maybe one of these green Locktites will work for me :unsure: ?

Danny,

All I can tell you is that John Ackerman glued in my bearings many times on an older OPS 65 and it held up very well during some very hard racing. I have no idea what he used but he's on this forum and you might send him a message and ask. Or try on RCBOATS forum.

Don

I really can't believe anyone including Ackerman would glue bearings in. If the housing is to loose to hold them in place there is no way that you can be sure the bearing is centered in the housing. Just buy a new housing/case and be done with it.

 

[Don Ferrette]

No one is seem to mention the special bearing tool from Novarossi for their engines.

Any one can give their findings on that one?

Ronald.

Every engine out there has it's own bearing alignment tool, it's called the crankshaft.

Once you've heated the case & removed old bearings you slide new big bearing on crank. Then drop crank with bearing on it into case. Set new small bearing in other end of case, slide on the flywheel collet & flywheel. Put flex collet on & snug it up. Spin the crank over a couple times while adding a few drops of oil to help cool the bearings. Let it naturally air cool rest of the way & you're done with bearings aligned to the crank they'll be running on. B)

 

[dannyual767]

If the housing is to loose to hold them in place there is no way that you can be sure the bearing is centered in the housing. Just buy a new housing/case and be done with it.

My housing can't hold the bearings in place but I wouldn't say that the housing is very loose either. It certainly isn't an interference fit anymore but I'm pretty confident that the bearings are centered. The problem that I have isn't a ton of clearance between the bearing OD and the housing ID. The problem is no interference fit.

I don't know how much Locktite #609 is but I sure don't like the idea of having to buy another bearing housing everytime I need to replace bearings . I've also got an OPS .67 that may need bearings soon and I can't justify paying that kind of coin for new housings each bearing change for these engines.

 

[Ray Sametz]

The crank only presses on the inner races of bearings. If you can make or buy mandrel for bearings it's better to set outer race to be sure. No loctite, buy new housing if not sure. Ray My nickle B) B) B)

 

[Jim Allen]

The important concept that both Ron, of Race Craft Bearings, & Ray have expressed is to make sure the inserted bearing is FULLY SEATED. THIS CANNOT BE DONE, WITHOUT USING EXCESSIVE FORCE, IF YOU ARE PRESSING ON THE INNER RACES ONLY! I agree that the crankshaft could be used to properly align inserted bearings, but only a properly designed bearing insertion tool, which presses on the outter race ONLY, while aligning the bearing , will do both things at the same time.

Pictures of these tools are in my photo gallery.

Jim

 

[RaceCraftBearings]

If the housing is to loose to hold them in place there is no way that you can be sure the bearing is centered in the housing. Just buy a new housing/case and be done with it.

My housing can't hold the bearings in place but I wouldn't say that the housing is very loose either. It certainly isn't an interference fit anymore but I'm pretty confident that the bearings are centered. The problem that I have isn't a ton of clearance between the bearing OD and the housing ID. The problem is no interference fit.

I don't know how much Locktite #609 is but I sure don't like the idea of having to buy another bearing housing everytime I need to replace bearings . I've also got an OPS .67 that may need bearings soon and I can't justify paying that kind of coin for new housings each bearing change for these engines.

Danny, I dont run OPS motors so I am not savy on how the bearings typically fit in them. I have only changed one set for a customer on a 67 and he stated after watching me that he never used heat he just pressed them in and out. Needless to say his housing was very loose around the bearings.

From what I gather in your post all OPS motors must have this problem even in a brand new motor? If this is the case then I would start using another brand of motor. It sounds as thou OPS stands for Ole Peicea S--t

Sorry couldn't resist!

 

[Don Ferrette]

The crank only presses on the inner races of bearings. If you can make or buy mandrel for bearings it's better to set outer race to be sure. No loctite, buy new housing if not sure. Ray My nickle B) B) B)

But if the case is still heated from removing the old bearings this is a non factor as they drop right in.