guzziriders.org - moto guzzi forum Homepage
Forum Home Forum Home > Technical > Big Block Tonti
  New Posts New Posts RSS Feed - 1977 T3. Timing chain, how long should it last?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

1977 T3. Timing chain, how long should it last?

 Post Reply Post Reply Page  <12
Author
Message
gates01264 View Drop Down
Falcone
Falcone


Joined: 09 Apr 2016
Location: andover
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote gates01264 Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jun 2016 at 22:25
Originally posted by DrD DrD wrote:

This is my winter job list for the LM.
Any views on this one:

http://hmb-guzzi.de/Timing-Chain-tensioner-CNC-made-HMB-design
This is the same style as the standard later v11 guzzi type tensioner that I installed in my 850 le mans and it works very well just eliminating chain whip.
I personally would stick to this style of tensioner and NOT the bow type tensioner!, put it this way, would you trust something that moto guzzi has developed and have used successively for years or trust something that has been badly engineered and looks like it has been manufactured in someones shed!

The reason i say the bow type tensioner is badly engineered is because of several design faults, one of which is when the bow tensioner is fitted the vertical spring on the tensioner presses hard horizontally against a lug on the engine casing causing the spring to bow, this will either fracture the tensioner spring due to it having a horizontal force placed on it or the spring will eat into the engine casing, neither of which is desirable.

The other reason is the excessive tension it generates, causing excessive radial load on the oil pump which has a  small diameter shaft supported by very small needle roller bearings housed in a delicate cage, and is clearly not designed to take this amount of force, resulting in accelerated pump ware or failure!
Anyway time to get off my orange box!

Edited by gates01264 - 01 Jun 2016 at 22:45
gates01264
Back to Top
Brian UK View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Surrey
Status: Offline
Points: 17641
Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jun 2016 at 22:37
The Spada III had a continuous whine from the timing chain with the aftermarket tensioner fitted, even tough the spring had broken. Cured when the proper late Guzzi one was fitted.
Brian.

Better 5 minutes late in this world than years early in the next.
Back to Top
Ken-Guzzibear View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Sileby Leics
Status: Offline
Points: 9454
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jun 2016 at 23:17
had my V1000 one done by Paul Harris there was a 10 degree lash in the old chain .... Guzzi ran .... doncha just love the engineering
The Older i Get, The Better I Was
Back to Top
Dave P. View Drop Down
Senior Member
Senior Member
Avatar

Joined: 12 Jan 2015
Location: Northants
Status: Offline
Points: 5573
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jun 2016 at 08:03
If Tonti had left well alone instead of penny pinching no chain related problems would or indeed could have arisen.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
Back to Top
Mike H View Drop Down
Senior Member
Senior Member
Avatar

Joined: 21 May 2014
Location: East Anglia
Status: Offline
Points: 8733
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jun 2016 at 14:00
That's the style of tensioner I had. Was 2nd hand tho and could've been shagged out, the spring had no strength in it to hold a chain in place as far as I could see.

I agree with Dave I'm intrigued what was the thinking process, somehow or other sprockets and chain were cheaper than gears, most likely because can buy in the latter from a sub contractor whereas making the gears in house cost more? Wacko

"Chicken nuggets don't dance on a Tuesday."
Back to Top
Jerry atric View Drop Down
Senior Member
Senior Member
Avatar

Joined: 24 Nov 2014
Location: Wiltshire
Status: Offline
Points: 3367
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jerry atric Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jun 2016 at 21:15
Originally posted by Brian UK Brian UK wrote:


The Spada III had a continuous whine from the timing chain with the aftermarket tensioner fitted, even tough the spring had broken. Cured when the proper late Guzzi one was fitted.

I guess thats a good description of the noise I hear although not vey loud. So should i be worried? there's no audible rattle from that area. The mileage is in the high 40,000s
Back to Top
gates01264 View Drop Down
Falcone
Falcone


Joined: 09 Apr 2016
Location: andover
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote gates01264 Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jun 2016 at 21:31
Originally posted by Jerry atric Jerry atric wrote:

Originally posted by Brian UK Brian UK wrote:


The Spada III had a continuous whine from the timing chain with the aftermarket tensioner fitted, even tough the spring had broken. Cured when the proper late Guzzi one was fitted.

I guess thats a good description of the noise I hear although not vey loud. So should i be worried? there's no audible rattle from that area. The mileage is in the high 40,000s

You know my view on this style of tensioner and the potential damage they cause so enough said from me I think
gates01264
Back to Top
 Post Reply Post Reply Page  <12
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.078 seconds.