new engine

[mattjohnson207]

What is this?  got it on ebag for $500

[Arizoni]

It's the lower half of a Royal Enfield Iron Barrel engine.

[mattjohnson207]

Fireball!... gotta go to work, serial # is  08G 1695.... quite a bit of side to side movement of aluminum con rod...Thamks, Matt

[Arizoni]

Due to the design of the lower connecting rod bearing there will appear to be quite a bit of sideways movement at the upper end.

The bearing is a floating sleeve design that has running clearance between the inside and the crankshaft journal and the outside of the sleeve has a running clearance between it and the lower connecting rod bore.
These two clearances working together cause the large movement of the connecting rod at the upper end.

Ace is the expert when it comes to these engines so I'll sit down over here in the corner and wait until he can comment.

[mattjohnson207]

Thanks Arizoni, apparently it's NOS,  there is no serial number on the raised  panel where it is on my AVL, those are just the numbers referencing the case halves.  I bought it in hopes of one day fireballing it, for right now, the AVL runs fine...my daily ride, just got it last nite, open to all suggestions including turning it into a 350.  Main goal is reliability and confidence, as I look towards retirement.   Thanks,  Matt J

[ace.cafe]

Yep, it's an Iron Barrel short block.
Later model Electric Start version.
It has the little oil-return connection next to the distributor with that little hose on it, and has the later type oil filler cap, which means it could be a 5-speed engine.

You can tell it's a 5-speed engine if you look at the back of the oil tank, near where the gearbox will mount on, and there will be a hole about 9/16" diameter all the way across the inside of the engine for the left-side shifter shaft to go thru it. If it has this, it will work with the left shift 5-speed tranny.

As nice as it seems to have new stuff, you really can't trust it with the stock parts in it for anything but a stock rebuild, so it really should be stripped-down and get new high-quality bearings in it at the very least, and a better con-rod and big-end bearing, with a real good truing of the crank before you put it back together, if you can swing it.

[mattjohnson207]

Thanks Ace,  No hole like there is on my '09 AVL, guess its a four speed.   Very interested in doing the best job possible on this engine, maybe Fireball  somewhere down the road, for now though, it goes in the closet . Will be pouring over old posts in the next few weeks to better educate myself .  Thanks again,  Matt J in  Glendale , Az.