« previous next »
Pages: [1]   Go Down

Author Topic: RC rod issue,  (Read 1039 times)

0 Members and 1 Guest are viewing this topic.

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,864
  • Saver of unloved motorcycles.
RC rod issue,
« on: February 25, 2023, 03:48:30 PM »
 I pulled the pistons off my RC836 motor for a top end job, it has RC rebuilt Honda rods with bushed small ends and 12 point bolts. 
  That would be good, but the #4 small end rod bushing is turned slightly so the oil holes aren't lined up with the holes in the rod. The bushing appears to have been installed that way, the pin or rod end aren't blue, the bushing is centered in the rod, doesn't appear to be worn or willing to turn, the piston pin doesn't wobble in the piston or bushing either.
 So my options appear to be, drill the oil holes, or leave it alone since it lasted this long. Drilling would create a pair of #8 shaped holes in the bushing.
 Opinions?
 

 
 
« Last Edit: February 28, 2023, 09:03:04 AM by Don R »
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Old Scrambler

  • My CB750K3 has been in 39 States & 5 Provinces
  • Old Timer
  • ******
  • Posts: 3,808
Re: RC rod Q?
« Reply #1 on: February 25, 2023, 04:26:41 PM »
With applied heat, I would attempt to remove the bushing and properly install it.............if not possible, drill it.
Logged
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline Tracksnblades1

  • My Son was a collegiate competition Trap, Skeet, and sporting Clay
  • Master
  • *****
  • Posts: 1,854
Re: RC rod Q?
« Reply #2 on: February 25, 2023, 04:29:06 PM »
Lightly heat rod end press out .
Let bushing cool in feezer or liguid no2.
Lightly heat rod end slip bushing in hold or pin align holes.
Let temperatures equalize.
Logged
Age Quod Agis

Offline scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,272
  • Humboldt, AZ
Re: RC rod Q?
« Reply #3 on: February 25, 2023, 07:02:39 PM »
DO NOT remove the bushing! When the bushing is pressed into the rod, the ID is compressed a tiny bit. After the bushing is installed, it is then honed to the final precise fit on the pin. Once you press the bushing out, you throw it away, press in a new bushing, and hone it to size.
Just drill the damn thing. ;)
Logged
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline calj737

  • Really Old Timer ...
  • *******
  • Posts: 21,021
  • I refuse...
Re: RC rod Q?
« Reply #4 on: February 25, 2023, 07:45:17 PM »
Quote from: scottly on February 25, 2023, 07:02:39 PM
DO NOT remove the bushing! When the bushing is pressed into the rod, the ID is compressed a tiny bit. After the bushing is installed, it is then honed to the final precise fit on the pin. Once you press the bushing out, you throw it away, press in a new bushing, and hone it to size.
Just drill the damn thing. ;)
Yup.
Logged
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,864
  • Saver of unloved motorcycles.
Re: RC rod Q?
« Reply #5 on: February 25, 2023, 11:13:49 PM »
  Drill baby drill. I had no confidence the bushing could be removed by me without destruction.
 
  I think the oil holes are so close to lining up, drilling a small hole on a slight angle may feed oil into the interior oil hole with a small loss of bearing surface area.
  This motor is full of surprises, it had an aluminum RC Engineering head gasket.
  I'd like to get this one running for use while I'm building a higher HP motor.
« Last Edit: February 25, 2023, 11:27:51 PM by Don R »
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,556
  • Bike almost back to the 70's 2015
Re: RC rod issue, action decided.
« Reply #6 on: February 26, 2023, 02:14:15 AM »
New bushings installed by a shop that know how to do?
Logged
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,864
  • Saver of unloved motorcycles.
Re: RC rod issue, action decided.
« Reply #7 on: February 26, 2023, 09:23:43 AM »
  Per, that obviously would be the best option, especially if I had split the cases. The automotive machine shops around here are mostly incompetent.
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,561
  • Big ideas....
Re: RC rod issue, action decided.
« Reply #8 on: February 26, 2023, 01:24:03 PM »
I've seen the same thing in other RC modified OEM rods. The bushing hasn't spun in the bore but it has shifted.
Rod bushings are a bit of a science. Good buddy of mine worked in the balancing business for close to 40 years. He ran into shifting bushings and tried thicker bushings, tighter interference fit etc but it actually made things worse. The  RC bushings were too thick in his opinion. Look at a Carrillo  bushing....much different with a thin bushing.
I think that bushing will continue to shift but it might take so long that it doesn't matter. ;D
Logged
Owner of the "Million Dollar CB"

Offline newday777

  • Really Old Timer ...
  • *******
  • Posts: 5,238
  • Avatar is my 76 K6 in Colorado w/Cody on back 1980
Re: RC rod issue, action decided.
« Reply #9 on: February 26, 2023, 04:43:34 PM »
Quote from: MRieck on February 26, 2023, 01:24:03 PM
I've seen the same thing in other RC modified OEM rods. The bushing hasn't spun in the bore but it has shifted.
Rod bushings are a bit of a science. Good buddy of mine worked in the balancing business for close to 40 years. He ran into shifting bushings and tried thicker bushings, tighter interference fit etc but it actually made things worse. The  RC bushings were too thick in his opinion. Look at a Carrillo  bushing....much different with a thin bushing.
I think that bushing will continue to shift but it might take so long that it doesn't matter. ;D
Hmmm. I'll have to take a look at the set I bought last year.
Logged
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,864
  • Saver of unloved motorcycles.
Re: RC rod issue, action decided.
« Reply #10 on: February 26, 2023, 05:46:17 PM »
 Crazy, I'll be sure they all get some assembly lube going back together.
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,864
  • Saver of unloved motorcycles.
Re: RC rod issue,
« Reply #11 on: February 28, 2023, 09:04:07 AM »
 I was thinking, is there anything you guys have not seen before? What an encyclopedia of information this site is.
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Ellz10

  • ZZ
  • Expert
  • ****
  • Posts: 760
  • Knowledge is Power
Re: RC rod issue, action decided.
« Reply #12 on: March 01, 2023, 09:57:23 AM »
Quote from: Don R on February 26, 2023, 09:23:43 AM
  Per, that obviously would be the best option, especially if I had split the cases. The automotive machine shops around here are mostly incompetent.

We must live in the same area  ;D
Logged
Thankful for everyone on this forum. Grateful to continue to learn so much.



'77 K7 - http://forums.sohc4.net/index.php/topic,193043.msg2251436/topicseen.html#new

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,864
  • Saver of unloved motorcycles.
Re: RC rod issue,
« Reply #13 on: March 01, 2023, 10:27:34 AM »
Quote from: Ellz10 on March 01, 2023, 09:57:23 AM
Quote from: Don R on February 26, 2023, 09:23:43 AM
  Per, that obviously would be the best option, especially if I had split the cases. The automotive machine shops around here are mostly incompetent.

We must live in the same area  ;D
My brother tried both local shops, one ruined his VW crankshaft, the other turned his air cooled VW rods into water cooled VW rods. There is one guy 12 miles away that is competent but bought a liquor store and isn't interested in new work.
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.
Pages: [1]   Go Up
« previous next »