77 eclat timing belt - LotusTalk - The Lotus Cars Community
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 09-22-2018, 01:05 PM Thread Starter
Registered User
Join Date: Sep 2018
Posts: 1
77 eclat timing belt

Hi, I am new to the forum, I have picked up a 77 eclat that needs some work. I was trying to change the belt from the air pump version to the 133 tooth and remove the air pump, but halfway thru I realized the idler isnt the adjustable one. Has anyone done this? Would I just need the adjustable(eccentric) one? Thanks for any advice. Dave W
damwar is offline  
Sponsored Links
post #2 of 3 (permalink) Old 09-25-2018, 03:05 PM
Registered User
QQROPA's Avatar
Join Date: Nov 2009
Location: South Jersey, USA
Posts: 345
assuming you have the 907 motor, this is the same engine in the Esprit. You should post your question to them for response. Post under the "Esprit" section. Good luck.

"Driving a Lotus is a triumph of bravery over intelligence." Stirling Moss

'73 Elan Sprint DHC
'91 Elan M100
'66 Elan S2 DHC
Odds 'n ends Lotus now 'n then...
TaylorMadeClassicCars on WWW and Facebook
QQROPA is offline  
post #3 of 3 (permalink) Old 02-21-2019, 09:23 AM
Registered User
Join Date: Aug 2004
Location: Minnesota, USA
Posts: 508
If you deleted the air injection pump and converted to the shorter 133 tooth timing belt, then do you have the special tension adjusting tool for the 138 tooth belt? If "yes", are you interested in selling it?

On to the main point. I'm late to this thread, so I hope you had the matter resolved long ago. But just for the record...

You have the choice of a spring-loaded, semi-automatic tensioner that was stock on Elite-Eclats of that period, or the eccentric tensioner that was used from 1986-onward. You may have to change the front seal housing to be compatible with your choice, but it's all 'possible' with Lotus parts.

If you go with the period-correct spring-loaded tensioner, then be aware that it got off to a troubled start, and went through a series of changes... there were six versions in total. For those who have early cars with the first tensioners, take care of them, and don't ignore maintenance!! Other than that, I'm not trying to create any paranoia.

But if you're out to buy one, then buy the newest version you can find find. The latest and best was used on the early, 1980-85 Turbo Esprit, as well as other Lotus cars of that same period. It has the Nylatron plastic piston, as well as replaceable plastic bushings in the hinge. Pass over any tensioners with the metal piston and a metal-to-metal hinge (no replaceable bushings).

A907E0913K, Last version, used on 1980-85 Turbo Esprit. Hex head adjuster screw.
Note part NUMBER change... 0913 Vs 0893 below, and 0855 below that:

B907E0893K, as used on late A/C equipped Elite & Eclat. Replaced:
A907E0893K, new version used on late Elite-Eclat (in both my '78 & '79 Eclats).
Note part NUMBER change... 0893 Vs 0855 below.

It replaced:
C907E0855K, which replaced B907E, which replaced A907E (Earliest & least desireable).

I like the spring-loaded tensioner. In theory, it's better than the non-compliant eccentric tensioner. However, it's a mechanism, and requries maintenance. It had a troubled early history, but many of the early problems were due to owners ignoring them until they broke. The later versions can take more neglect, and the critical hinge wear points are rebuildable... just replace the plastic bushings. Without the bushings, hinge wear means throw away the tensioner.

But if you're not good at maintenance, then you should consider the eccentric tensioner. The eccentric tensioner still needs maintenance, but less "mechanical" maintenance on the tensioner itself. While the semi-automatic tensioner can compensate for belt stretch, the eccentric can't. So, with the eccentric you'll find it necessary to periodically check and re-set the timing belt tension. You've traded tensioner maintenance for belt tension maintenance. Choose between tensioner types... but avoiding 'belt' maintenance all together is NOT a choice on 9XX engines!

All Lotus tensioners use the same bearing.

The best place to shop for out-of-production tensioners is probably Lotusbits in the UK. They specialize in used/ salvage parts. They can sell one to you in as-is condition, and you rebuild it. Or they can rebuild it for you at extra cost.
Lotus Excel parts, Lotus Esprit parts and Lotus spares, new and used

I hope you had your Eclat running last Fall, and have enjoyed driving it.

Tim Engel

Last edited by Esprit2; 03-02-2019 at 08:18 AM.
Esprit2 is offline  
Sponsored Links

  LotusTalk - The Lotus Cars Community > Lotus Discussions > Other Lotus Models

Quick Reply

Register Now

In order to be able to post messages on the LotusTalk - The Lotus Cars Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

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


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

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