Source for crank main bearings

[shootingsight]

One of the main bearings on my crank is bad.  It is a 0.50mm oversize.  The bearing I have is marked, but I have googled and cannot find any references.  THere is one crank shop left in town, and they seem to never answer the phone.

Can someone please point me to a source for bearings, or at least a cross reference to a modern bearing that will fit?

Thanks,

[dakazman]

  What engine do you have?
 Dakazman

[dakazman]

  If it’s a 1565 wedge or crossflow I have a set.

[jbcollier]

Maximum grind on Renault crank is only 0.10”/0.25mm.  After that the crank also has to be nitrated.

[shootingsight]

It's a Renault S2, but I'm pretty sure maximum is +0.50mm.

In any event, it was reground 30 years ago and had new bearings then.  Issue seems to be that there were metal shavings in the oil galleys that were not cleaned out.  So it only had a few hundred miles since the rebuild and went into storage.  Now, I ripped apart the engine and found the shavings in the oil pump strainer, and one of the bearing has major scoring, but the crank is undamaged.  So I'm looking to replace the bearing that is in there.  I'll post the bearing data as soon as I get back.

Symptom I saw back then was great oil pressure till the engine got hot, once hot, the idle pressure dropped down.  So I'm thinking if I replace the scored bearing, it will be great.

[jbcollier]

Service limit for oil pressure is 10 psi per 1000 rpm.  Not saying you don't need to fix it. 0.50" show up on ebay. 

[shootingsight]

The +0.50 that show up on ebay are 4 pair, but it is a 5 bearing crank, so I suspect they are rod big end bearings, not mains.  I'll verify, but I do not think they are the same.

[GavinT]

The +0.50 that show up on ebay are 4 pair, but it is a 5 bearing crank, so I suspect they are rod big end bearings, not mains.  I'll verify, but I do not think they are the same.

Sounds right - 4 pair isn't for the crank.
King bearings # MB 533 AM is for the STD size. The "MB" denotes Main Bearings.

These look right for the undersize set but it may be prudent to contact the seller to make sure.

https://www.ebay.co.uk/p/King-RENAULT-R16-0-5-Main-Bearings/602769625?iid=112578703928

[dakazman]

The +0.50 that show up on ebay are 4 pair, but it is a 5 bearing crank, so I suspect they are rod big end bearings, not mains.  I'll verify, but I do not think they are the same.

Sounds right - 4 pair isn't for the crank.
King bearings # MB 533 AM is for the STD size
 
Gavin , so for the novice I am , this means uncut crank , STD and . 50 cut on the mains?
Dakazman

[GavinT]

 
Gavin , so for the novice I am , this means uncut crank , STD and . 50 cut on the mains?
Dakazman

Yes, STD means suitable for the Standard crank dimension of 54.80mm.

Looking at your pic, it additionally shows .50 which presumably means suitable for a crank that's ground .50mm undersize . . which is ~ 0.020 inches undersize in the old money.

[shootingsight]

Many thanks to all, this agrees with what I found: MB 533 AM from King seems like the correct bearing for the engine.  I need MB 533 AM 0.50 for the 0.50mm oversize.  I found two vendors from Lithuania on ebay and also emailed a King distributor here in the US.  Seems this bearing was not just used in the R16, but also looks like some Fuegos.  Are Fuego engines compatible with the Lotus?

I do not have the correct engine.  Years ago, my Lotus block cracked when it froze, so I replaced the block with a R16 block.  The one I have is an 821-10 engine.  I'll see if I have the old block stashed somewhere to get the type plate.  At the time this happened, 40 years ago, it didn't occur to me to write down the block type :-).  So I *think* the block type is correct, and I kept the Lotus head, but the block type is likely off.

The +0.50 that show up on ebay are 4 pair, but it is a 5 bearing crank, so I suspect they are rod big end bearings, not mains.  I'll verify, but I do not think they are the same.

Sounds right - 4 pair isn't for the crank.
King bearings # MB 533 AM is for the STD size
 
Gavin , so for the novice I am , this means uncut crank , STD and . 50 cut on the mains?
Dakazman

[GavinT]

Seems this bearing was not just used in the R16, but also looks like some Fuegos.  Are Fuego engines compatible with the Lotus?

Yep, but there's a need to be specific, here.

I expect the Fuego engine they're talking about would be the 843.
The 843 uses the same main and big end bearings as the 821, 807, 843, 844 etc.

That means the MB 533 AM bearings would be suitable for a Fuego (using the 843 engine), R16, R15, R17, R18 etc.

I'm deliberately ignoring the very early 697 engined R16's as irrelevant to your quest.
And be aware, they also fitted a 2 litre OHC engine to the Fuego which is what we got here in Australia - different engine altogether.

Hope that makes sense.

[shootingsight]

Interesting ... I guess what I'm asking, and likely it's too optimistic, is if there is another Renault engine that can easily be swapped in to the Lotus.

I say optimistically, because I'm presuming that if the bearings are the same, that means at least the bottom of the block is the same .... so maybe the rest of the block is similar enough that engine mounts align, and bell housing mounts align, and there is something that offers a horsepower boost ..... though presumably, if it were that easy, lots of people would be doing it :-)

[GavinT]

Yes, there's a lot of commonality within this "family" of engines and also some nuances to be aware of.
Richard Mann covered many aspects in this thread:

http://www.lotuseuropa.org/LotusForum/index.php?topic=1748.0

[jbcollier]

It's common to drop in a Renault Hemi/Crossflow engine which is the same block.

Renault 16 shop sells reground cranks to 0.010/0.25.