Crankshaft question

[Andy338]

I recently bought a 1969 Europa S2 that came with a spare motor. The motor in the car is non matching and the spare is also non matching. The motor in the car is a 821-02 and has flat top pistons and the spare motor is a 821-30. The car has been off the road since 1982. It is very complete and has a Hermes intake with a Weber 45 side draft carb. The body needs some fiberglass work as well as a paint job. I have owned, restored, and rebuilt British motorcycles for the past 25 years, mostly BSA's and have been vintage road racing some of my BSA's for the past 18 years. I decided to broaden my British collection and bought the Europa. I have dismantled the spare motor with the plans to rebuild it and put that motor in the car. Upon tearing the motor down I noticed (see pic) this missing piece of metal from one of the crank journals. It appears to me to be a casting flaw and not something that occurred while the motor was running as there is no signs of any other damage caused on the bearing journal surface or on the bearings themselves. There are also no rough edges on the missing area. Has anyone else noticed this on any Renault crankshafts. I'll try to post some pictures of the car soon. Thanks in advance.

[GavinT]

Weird - never seen anything like that before. What does the bearing shell look like?
I can't imagine that would have passed any QC environment so it must have occurred post production.

[Richard48Y]

Lots of crank shops can fix that, is it still standard diameter?
New cranks are available for about $600.
If you go with new you also get some choice in stroke and displacement.
Beware of mission creep!

[TurboFource]

 

[Andy338]

There's no damage to the bearings that were on that journal. Also I don't believe the crank has been reground. I haven't had a chance yet to measure the journals with a micrometer but measuring with my dial calipers, the journals are still original size.

[dakazman]

 
 Andy 
  We love some pics. Post often your process in building her back up . You’ll also find many helpful manuals and schematics.
    eBay got a few for sale
https://www.ebay.com/itm/176112738554?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=j59yRRHmTm2&sssrc=4429486&ssuid=QOunqopVSxS&var=&widget_ver=artemis&media=SMS
 Dakazman

[jbcollier]

Welcome!

I have seen a lot of cranks in my 35 years as a mechanic.  That's a first for me.  Myself, I would use the crank out of the other engine.  The Renault engines only had a 10 thou undersize option due to the case hardening of the journals.  The divot is way more than that.

[BDA]

  Andy!!

That’s a strange one! I would check to see if it can be repaired but I think I’d be more comfortable replacing it.

[Richard48Y]

At the least I would have the crank X-Rayed.
That is a visible occlusion, what else may lurk below the surface?
You do not want to create a Window in the block!

[Andy338]

Thanks for all the replies so far. I've considered pulling the crank from the motor in the car but I've been hesitant in case I needed to roll the car around. I guess I could pull that motor and put one of the engine blocks and the gearbox back into the car in order to be able to move it but that seems like a lot of extra work. I may just look into buying a crank. Here's a picture of my car.

[Richard48Y]

I recently had a crank turned and the cost was high enough that a new crank would not have been a lot more.
With welding and redoing the surface hardening a new crank may be cheaper.

[Bainford]

Welcome to the forum, Andy. That's a good looking project. Cheers 

[buzzer]

that also looks scored enough to me to need a regrind. a pic of the bearing would be interesting.  a replacement crank i think. i wouldn't bother with anything else