PV Crankcase differences

[paulincayman]

Hi , all ,
 Been looking at my two sets of 29L crankcases  trying to decide which one is better for the build,  the better of the two is marked 29L-00, but it is slightly different to the other ( later?) set marked  29L-01 in that it has a rectangular cut out in the bottom of the lower case right below the neutral switch cover , it is perfectly formed and there is no sign of damage anywhere so I'm assuming it was made that way .  The later 29L-01 case has that hole filled in , you can still see the faint outline of where the mould was modified .
 Anyone has a theory why the earlier one had the cutout and then why it was filled in ,.
 Really asking because I want to use the earlier case and was considering  filling in the cut out. 
 TIA 
Paul

[midlifecrisisrd]

The cut outs are a mystery

I've seen them on early and later cases

Do they have the indent on the upper edge where the RH carb bowl would be

Steve

[paulincayman]

Don't see anything like a dimple/indent. These are 31k cases if it makes a difference. I think I'll fill it in anyway.

[JonW]

I thought it was there as a drain of some sort, for rainwater etc

[JonW]

A thought: Do the AC cases have it?

[pdxjim]

Oct 15, 2019 3:27:54 GMT 1 JonW said:

I thought it was there as a drain of some sort, for rainwater etc

Exactly what I was gonna say ... place for the rainwater and excess chain lube to drain out.

[paulincayman]

If that were the reason then why blank it off in later versions? Scratching my head.

[JonW]

Might have cost 10c more to tidy it up when out of the mould, or they found it was more likely to crack if it got hit by a stone or the bike got dropped, let alone what might happen when the chain snaps.

[midlifecrisisrd]

I reckon it was to stop you having to get this done after the weak bit gets broken

Steve

[paulincayman]

Well that seems sensible..dev filling mine in .
Thanks all.

[JonW]

I doubt youre going to snap a chain Paul, you'll look after it unlike the yoofs of old

[dusty350]

Aircooled engines had the cut out too;

1 by dusty miller, on Flickr

If it were me, I would leave as is. I've not had an engine with that bit broken off before when it's been cut out. You are more likely to break the top part of the casing off with a snapped chain ( had a couple of those cases with damage)

Dusty

[paulincayman]

Sage like as always Dusty..leave as then. Case closed (left open ).