Author Topic: 807 crankshaft bearing clearances  (Read 118 times)

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Offline BERNIEHUMBER

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807 crankshaft bearing clearances
« on: Sunday,May 14, 2023, 04:55:47 PM »
HI:
In the process of getting some Plastigauge to make sure of main and crank bearing to shaft clearances.
What should I be looking for as min/max for bearing clearances?
The crank was reground somewhere in its life and I want to be sure of the bearing clearances.
I use 1 thou for ever 1 inch of crankshaft dia.
The main would be 2.2 thou and the crank 2.0 thou.
From those with experience in the 807 rebuild does that sound ok?
Thanks

Offline dakazman

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Re: 807 crankshaft bearing clearances
« Reply #1 on: Sunday,May 14, 2023, 05:32:06 PM »
  I check to see if I have the 807 specs specifically.
 Have you seen this link ?
http://www.lotuseuropa.org/images/WorkshopManual/S2_Section_E_-_Engine.pdf

 This is what I have on an 807 , see pic

   Dakazman
« Last Edit: Sunday,May 14, 2023, 05:44:33 PM by dakazman »

Offline jbcollier

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Re: 807 crankshaft bearing clearances
« Reply #2 on: Sunday,May 14, 2023, 08:41:52 PM »
I went spelunking into my manuals and gradually remembered we've been here before.  Renault doesn't list crank/rod oil clearances.  They give crankshaft diameters and wear limits, but that's it.  Going from LOTS of experience, the oil clearance should range between 1.5 thou and 3 thou with optimal being 2 thou to 2.5 thou.  Anything less than 1.5 thou is just too tight, and above 3 thou, too loose.

 If you are building a racing engine, you would 2.5 thou to 3 thou for a looser fit to suit an engine that is going to live in the higher rpm ranges.

Offline BERNIEHUMBER

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Re: 807 crankshaft bearing clearances
« Reply #3 on: Monday,May 15, 2023, 06:05:35 AM »
HI:
Thanks for the input.
I checked a Renault manual that includes the 807 and it didn't give me that reground clearance that I was after (like what you have shown Dakazman). 
I hope this engine to be more of a reliable street engine with a bit of snap to it than anything else.
My Shannonville days are past me now.