Hi Terry,
Thanks for the technical discussion on washers.
I'm not sure I understand the first part of your email though...
> This is a different engine so it might be comparing
> apples to oranges. I can see the theoretical
> improvement in internal lube (it is identical in size
> to the oil holes in the front/rear mains) but feeds an
> extra rod, it's weight and the center, biggest part of
> the crank. Also, the same oil pump is used on the 2
> litre in-line 6's, so the pump should be able to keep
> adequate pressure through a slightly larger hole.
I have an old 6 cyl motor apart here, and noticed that the oil pump is
larger - about half again as tall as the Spit version.
I'm also not sure what this means...
> They said
> they'd never heard of anyone widening the center oil
> galley and that they would prefer not to do it, as
> there was more risk of damaging the block than any
> benefit would have been gained from widening it that
> extra fractional ammount.
Are you thinking of a motor which has the thrust washers in the centre main
bearing? If so, I can see the logic in that. However the Spit has the
thrust washers only on the upper half of the rear main bearing.
>had already widened it in the past, but according to
> the shop the center was already very close to a 5/16"
> size.
I estimate the rear main bearing oil hole is about 1/4", which feeds only
the rear main and rear rod. So I'm thinking a 1/32" or smaller hole to the
thrust washer would not adversely affect the amount of oil getting to those
parts.
I'll reearch further,
Thanks for your input. Fred
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