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Lotus Europa Forums => Garage => Topic started by: Richard48Y on Wednesday,January 17, 2024, 06:25:33 PM

Title: Fitting cam gear to Renault engine?
Post by: Richard48Y on Wednesday,January 17, 2024, 06:25:33 PM
My Renault manual says "Pressed", but leave a specified gap.
How are other doing this?
I'm wondering about warming the gear and chilling the end of the cam using dry ice?
Title: Re: Fitting cam gear to Renault engine?
Post by: GavinT on Wednesday,January 17, 2024, 11:45:41 PM
The few times I've done it was with a hydraulic press & everything at ambient temperature - seems to work OK.

The manual assumes new parts but given the years that have rolled by, it's probably a good idea to calculate/check the press fit.
I don't recall the manual calling out any specifics re dimensions so I guess it's off to the machinery handbook.
Title: Re: Fitting cam gear to Renault engine?
Post by: Richard48Y on Thursday,January 18, 2024, 12:17:35 AM
Manual specifies a small gap between the back of the gear and the base of the cam.
New billet cam and new adjustable timing gear.
I have a thirty ton press so can certainly cram it on.
Hoping for a less brute force method.
Title: Re: Fitting cam gear to Renault engine?
Post by: GavinT on Thursday,January 18, 2024, 05:35:22 AM
Yes, the end float is specified but not the class of interference fit & tolerances.
Still have a stock Renault cam and sprocket? Perhaps it's possible to reverse engineer the spec.

On the Alpine A110 rally cars they installed a bolt in the end of the cam.
I'm not sure if it was a belt 'n 'braces idea or because they pressed the sprocket off and on more regularly that the factory had anticipated - maybe both.
Title: Re: Fitting cam gear to Renault engine?
Post by: jbcollier on Thursday,January 18, 2024, 11:59:06 AM
It’s just a simple press fit.  Just go slowly as you get close to spec.
Title: Re: Fitting cam gear to Renault engine?
Post by: BERNIEHUMBER on Friday,January 19, 2024, 08:42:42 AM
HI:
I put the gear in the oven on a pan my wife ok'd.(warmed up to 170 F)
I put the cam shaft in the freezer over night.
I then put the cam shaft in a wooden vice and with a feeler gauge tapped the gear in with a wooden mallet.
Don't forget to put on the mounting plate before you start the gear install(the best laid plans of mice and men).
This methodology has worked a few times with good outcomes.
Title: Re: Fitting cam gear to Renault engine?
Post by: dakazman on Friday,January 19, 2024, 02:22:34 PM
HI:
I put the gear in the oven on a pan my wife ok'd.(warmed up to 170 F)
I put the cam shaft in the freezer over night.
I then put the cam shaft in a wooden vice and with a feeler gauge tapped the gear in with a wooden mallet.
Don't forget to put on the mounting plate before you start the gear install(the best laid plans of mice and men).
This methodology has worked a few times with good outcomes.
  I still would have been killed because I didn't say it stinks... :FUNNY:  anyway I just heated  the gear with my acetylene torch until on it went on moved where I wanted it . Off and away from the engine.
Dakazman