[Spridgets] Main bearing caps 1275

Daniel1312 at aol.com Daniel1312 at aol.com
Tue Jun 12 12:49:33 MDT 2007


Hal,

The centre main has a harder life than the end bearings so generally it's 
only the centre main that gets the reinforcing strap.  I have however, seen a 
photo of an A-series engine with all 3 bearing caps strapped.

In my opinion it's simpler not to bother having the centre main strapped but 
to have a steel 4 bolt main instead.  Ok it's not simpler as the block has to 
be drilled and tapped.  I think you can get 2 bolt performance main caps and a 
set of 2 bolts and a set of 4 bolts.

When the old engine comes out of my car and the new one is in and running 
I'll pull the sump to have a look to see what the engine builder did with the oil 
pickup pipe.  Remember both Vizard and Hamill are very bias in text and 
photos to the transverse A-series.  The new engine in my Sprite is having a 4 bolt 
main and it is drilled and tapped for the oil pickup pipe.  If you get a 4 
bolt main for the Mini (or Austin Metro) you'll find it isn't drilled and tapped 
for the oil pickup pipe.

Have a look at www.aptfast.com  and their section on main bearing caps and 
stuff.

Regards

Daniel1312


In a message dated 12/06/07 19:24:49 GMT Daylight Time, hal at katemuir.com 
writes:


> Spridgeteers,
> 
> I notice that both Vizard and Des Hammil recommend strapping the center main
> bearing cap on an A-series engine.  No one says anything about the other
> two.  Is it desirable to strap either of the others?  I am thinking of the
> rear main in particular.  Any suggestions, ideas?
> When the center main cap is strapped what happens to the oil pick-up
> bracket?  Should the strap be drilled and tapped and the bracket modified,
> or is one attachment point sufficient?  It seems  that if the oil pick-up
> works loose it could have rather deleterious effects on the bottom end of
> the motor, either by oil starvation or by direct interference with the
> motion of the crank.
> 
> Hal


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