T120 OIF Frankenhead - Triumph Forum: Triumph Rat Motorcycle Forums

Classic, Vintage & Veteran For Coventry and Meriden Models. Anything pre-Hinckley goes.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 11-24-2012, 11:45 PM Thread Starter
Lifetime Premium
Site Supporter
SOTP Vintage Series
Main Motorcycle: 2006 Thruxton
 
jonkster's Avatar
 
Join Date: Jan 2009
Location: Sydney, Australia
Posts: 6,564
Other Motorcycle: 1971 T120
Extra Motorcycle: Ossa 6 day replica
Garage
T120 OIF Frankenhead

Summary: can I use a '72 set of T120 rocker boxes on a '71 and using the '71 head bolts and rocker box bolts?

Details:

I have a 1971 OIF T120 with a non OIF head. (or if it has the right head it definitely has the wrong head bolts).

This is what is on it at the moment:


I am not interested in making a perfect 1971 bike - I just want a reasonably reliable rider. (Having the wrong rocker boxes and long head bolts will make it hard to remove the engine and at the moment the head is also currently leaking so I want to get in here to see what is going on)

I am not sure how they got the motor in there with the older head bolts - I am assuming they jacked and tilted the motor while it was in the frame to insert the long head bolts. I am guessing to get the head off I will need to do the same.

I have sourced a set of 1972 rocker boxes (the ones with the larger opening - I figure that will make adjusting valve clearances easier) and also 4 1971 hex headed head bolts (rather than the round headed 1972 ones) and '71 rocker box bolts.

the 72 boxes and a 71 head bolt and rocker bolt:


Once I get the old bolts out, I am hoping I can simply bolt on the 72 rocker boxes with the 71 head and rocker box bolts.

Is there anything special about the 72 rocker boxes that require 72 bolts? Once I get the old bolts out, should this be a straightforward?

Aunty Mabel
jonkster is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 11-25-2012, 08:14 AM
Senior Member
Legend
Main Motorcycle: 72 Bonneville T120RV
 
triumpt120rv's Avatar
 
Join Date: Aug 2010
Location: Canada
Posts: 10,806
Quote:
Originally Posted by jonkster View Post

Is there anything special about the 72 rocker boxes that require 72 bolts? Once I get the old bolts out, should this be a straightforward?

The 72 round bolts have a 3/8" allen inside to torque your head with the rockers still on. The 71 bolts have a 7/32" allen which is too flexible when torquing (which is why Triumph changed to 3/8" in 1972ish). 72 bolts are preferred.

Ensure that you use the proper thickness washers under the rockers between the rocker cover and the bolts. They are thicker than stock washers and prevent the crushing of the rocker boxes (which may or may not be the cause of your leak. Look for washers # 82-2184 (not 82-1814 as indicated in pic below) You will need 4 of them.

Here is a great pic of 71, 72, and 73 onward bolts from "triumphmike" posted on another site:


Last edited by triumpt120rv; 11-25-2012 at 08:20 AM.
triumpt120rv is offline  
post #3 of 11 (permalink) Old 11-28-2012, 01:31 AM
TE Lifetime Contributor
Team Owner
Main Motorcycle: Rickman T120
 
Join Date: May 2010
Location: Victoria Australia
Posts: 4,721
Other Motorcycle: T160,TR6
There is another stud kit that you can get from Coventry Spares,in the US.
It has 26tpi at the bottom of the stud to suit the 650 barrel.The stud also bottoms out at the bottom of the tapped hole in the barrel (don't tighten down hard),to avoid distorting the head face (a problem with the normal T140 stud setup).
The studs have a 3/8" x 24 tpi thread at the top,to fit the T140 allen head nuts.

If your head is 1971 or later,just use the '72 rocker boxes.If the head is 1970 or earlier,there may not be enough metal around the inner head studs to seal the rockerbox gasket.You could fill the head in that area with JB-Weld,to get enough gasket surface.It only has to seal the gasket,and won't be highly stressed.
Mr.Pete is offline  
post #4 of 11 (permalink) Old 11-28-2012, 04:12 AM Thread Starter
Lifetime Premium
Site Supporter
SOTP Vintage Series
Main Motorcycle: 2006 Thruxton
 
jonkster's Avatar
 
Join Date: Jan 2009
Location: Sydney, Australia
Posts: 6,564
Other Motorcycle: 1971 T120
Extra Motorcycle: Ossa 6 day replica
Garage
Thanks for that fellas.

Mr P, I tried to search for Coventry Spares to see if I could order those bolts but not having much luck. I can get a street address but wondering do they have a web site?

Aunty Mabel
jonkster is offline  
post #5 of 11 (permalink) Old 11-30-2012, 05:28 PM Thread Starter
Lifetime Premium
Site Supporter
SOTP Vintage Series
Main Motorcycle: 2006 Thruxton
 
jonkster's Avatar
 
Join Date: Jan 2009
Location: Sydney, Australia
Posts: 6,564
Other Motorcycle: 1971 T120
Extra Motorcycle: Ossa 6 day replica
Garage
I have been searching for the studs Mr P mentioned without much luck.

Possibly silly question but... suppose I was to take some older head bolts (ie the long pre OIF ones) and cut them and thread one end with 3/8 UNF. I would have some 26TPI CEI to 3/8 UNF studs I could use with T140 top bits.

Any reason this wouldn't work?

Aunty Mabel
jonkster is offline  
post #6 of 11 (permalink) Old 11-30-2012, 10:11 PM
Senior Member
Legend
Main Motorcycle: 72 Bonneville T120RV
 
triumpt120rv's Avatar
 
Join Date: Aug 2010
Location: Canada
Posts: 10,806
While you're waiting for Mr. Pete or others to pipe in about the studs, ponder using 72 bolts if you have them readily available. They will require no modifications and give good service.

P.S. I believe you will have to modify the holes on the 72 rocker boxes to fit the 74 top bits as well.
triumpt120rv is offline  
post #7 of 11 (permalink) Old 01-20-2015, 04:19 PM
Senior Member
Team Owner
Main Motorcycle: Triumph TR7
 
Join Date: Feb 2012
Location: Norwich, England
Posts: 4,174
Other Motorcycle: T140
Extra Motorcycle: Most of another T140
Quote:
Originally Posted by jonkster View Post
Summary: can I use a '72 set of T120 rocker boxes on a '71 and using the '71 head bolts and rocker box bolts?

Details:

I have a 1971 OIF T120 with a non OIF head. (or if it has the right head it definitely has the wrong head bolts).

This is what is on it at the moment:


I am not interested in making a perfect 1971 bike - I just want a reasonably reliable rider. (Having the wrong rocker boxes and long head bolts will make it hard to remove the engine and at the moment the head is also currently leaking so I want to get in here to see what is going on)

I am not sure how they got the motor in there with the older head bolts - I am assuming they jacked and tilted the motor while it was in the frame to insert the long head bolts. I am guessing to get the head off I will need to do the same.

I have sourced a set of 1972 rocker boxes (the ones with the larger opening - I figure that will make adjusting valve clearances easier) and also 4 1971 hex headed head bolts (rather than the round headed 1972 ones) and '71 rocker box bolts.

the 72 boxes and a 71 head bolt and rocker bolt:


Once I get the old bolts out, I am hoping I can simply bolt on the 72 rocker boxes with the 71 head and rocker box bolts.

Is there anything special about the 72 rocker boxes that require 72 bolts? Once I get the old bolts out, should this be a straightforward?
This was over 2 years ago Jonkster. Its the same engine that you're currently saying you've just bought from Blind Jack or whoever. I reckon you're winding us up. If I'm wrong I'll apologise after understanding what's been going on. If I'm not, why?
JohnA is offline  
post #8 of 11 (permalink) Old 01-20-2015, 04:55 PM Thread Starter
Lifetime Premium
Site Supporter
SOTP Vintage Series
Main Motorcycle: 2006 Thruxton
 
jonkster's Avatar
 
Join Date: Jan 2009
Location: Sydney, Australia
Posts: 6,564
Other Motorcycle: 1971 T120
Extra Motorcycle: Ossa 6 day replica
Garage
No John, definitely not meaning to wind you up at all and yes it is exactly the same bike.

The first 4 posts in my current thread in the projects section covers a period of about 3 years (I bought the bike and after a start on it, life got in the way so only now getting back to it - I thought I made that clear in the thread - sorry if I didn't).

I mentioned in that thread about asking here about the head and finding out the bolts and head were wrong - after this thread I then waited about 2 years before I got the new head and bolted it on.

Been a hectic few years in my life and motorcycles (at least fixing them) had taken a back seat.

Aunty Mabel
jonkster is offline  
post #9 of 11 (permalink) Old 01-20-2015, 06:33 PM
Senior Member
Team Owner
Main Motorcycle: 1971 t120r
 
rambo's Avatar
 
Join Date: Mar 2005
Location: exmouth devon uk
Posts: 4,792
Other Motorcycle: triumph rocket 111
Extra Motorcycle: BSA Spitfire
Nothing about the head,but i would get rid of those two red wires.There are so many bolts locating that engine, that would make an engine earth pointless.Maybe,if you feel the need,run a wire from the battery to a rear engine mount bolt.Almost invisible then.
rambo is offline  
post #10 of 11 (permalink) Old 01-20-2015, 08:26 PM
Senior Member
World SuperBike
Main Motorcycle: T160
 
Join Date: Oct 2011
Location: Great Britain
Posts: 2,319
Other Motorcycle: T100, T150
Hi,

Quote:
Originally Posted by jonkster View Post
tried to search for Coventry Spares to see if I could order those bolts
You might've worked this out already but ... Coventry Spares is a (the?) US Triumph parts wholesaler (owned by contributor "johntioc"); you'd order the parts from a US dealer and they'd get 'em from Coventry Spares.

Hth.

Regards,
StuartMac is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options
All posts must adhere to Forum Rules

Register Now



In order to be able to post messages on the Triumph Forum: Triumph Rat Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter your valid email address, that can receive an automated confirmation message. Otherwise, you won't be able to gain full access.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
68 t120 mossy Classic, Vintage & Veteran 0 11-27-2011 08:00 PM
T120 Tuning Help sjw867 Classic, Vintage & Veteran 5 03-15-2010 10:12 PM
'69 T120 Wiring Help sjw867 Classic, Vintage & Veteran 4 03-09-2010 06:12 PM
We need a T120! OldSwede Air Cooled Twins Talk 30 05-22-2008 05:22 PM
67 and 70 t120 mattyg Classic, Vintage & Veteran 3 09-11-2005 09:06 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome