<VV> Engine building - bearing clearance

[Tony Underwood]

At 03:22 PM 1/22/2010, Chris & Bill Strickland wrote:
>As for align-honing Corvairs, it's only for racers and dedicated
>machinist types -- a replacement block is FAR less expensive in a
>Corvair.  Now in some cars, like Porsche, where each engine is serial
>number matched to a specific chassis,


US makers been doing this since the '60s.


>and there is therefore a greater
>desire to preserve or restore an original block (among some folks), yes,
>it is much more common.  "Numbers matching" are high dollar buzz words


...and an excuse to demand big number bucks for no good reason...


>these days, offering monetary incentive to do a bore alignment to save a
>block.



"Numbers-matching" on a restored '60s vintage performance car 
generally means it's useless.


...knew of a guy a while ago who spent giant dollars to fix a Hemi 
block out of a Challenger that had been a bracket racer for some 
years, was being returned to stock via a serious 
restoration...  since a 1970 Hemi Challenger was becoming a somewhat 
desirable car and the guy predicted (correctly) that it could only go 
up in value as time passed.

Original 426 engine (block still slowly rusting away in the previous 
owner's basement) had tossed a rod at ~7500 rpm and taken out half of 
the side of the crankcase and broke the starter off the engine, 
taking the bottom dogleg off the block's bellhousing flange mount with it.

New owner of the car paid who-knows how much money for a foundry to 
repair that demolished block and stipple the exterior to make it look 
like a stock casting.   I recall it needed two sleeves as 
well.    Saw it on an engine stand at my bud's shop going back 
together... outside, except for the different colors of metal, (not 
an issue once it was repainted) the block looked stone 
stock.    Inside, it had welds from Hell and back.

The irony here is that the broken off pieces (which the original 
owner also still had) that contained the Challenger's VIN had broken 
across and through the number stampings and had been welded up in the 
repair so much that the VIN had been obliterated... the owner ended 
up restamping the numbers back onto the pan rail.


My buddy at the shop mumbled something about "...why the Hell he 
didn't just go ahead and stamp numbers on another unbusted stock 
block is beyond me."    This was back around the early1980s when a 
good used Hemi block was still available for around 500-600 bucks if 
you knew somebody.


I remember staring inside and outside that engine, mumbling "That's 
dedication".




tony..