John Clark wrote:
>
> Hello all,
>
> I was looking in the McMaster-Carr catalog today for replacements for the
> motor mount spacing washers.
>....snip....<
>
> Can anyone tell me if 18-8 stainless steel is strong enough for this?
>
> Thanks.
>
> - John
John,
>From a structural and corrosion standpoint a stainless washer is a fine
choice, as it is in compression. It's the grade of bolt that needs care.
High strength critical applications need Grade 8, and they do not come
in stainless, as the material can not be tempered as strong.
OK. The direct answer to your question. BUT, there is a new twist to
this story:
>From another standpoint I need to point out a potential error I made
that may lead to confusion unless I can get this confirmed by others.
When I replaced my stock fan with the Ford Canadian 6 blade I carefully
measured the rack distance from the hub, and had the blades
circumferentially cut using a vertical mill that rotated the blades
around the exact center. It worked fine, and was autoatically balanced.
When later replacing the manifold with an F4B and a stock hood I had not
caught on to how Edelbrock easily handled the PCV valve vacuum and the
465 CFM Holley carb, which does not have an inlet (it was designed
before the were required). An expensive BOSS 302 1/4 inch plate, with
inlet, was still too tall, and the bonnet wouldn't close. So I
substituted a 600 CFM throttle plate with an inlet. ($$$$)
Meanwhile, as luck would have it, my well meaning mechanic, while
replacing the old motor mounts, did me a favor and left out the spacer
washers. This was unknown to me, as I had already solved the problem and
he did not know. It lowered the motor and I didn't know. I did notice a
strange vibration around 1800 rpm, which seemed to go away at about 2500
RPM. Couldn't figure out where it was coming from. Later the noise
stopped. I saw that the tips of my exquisitely machined fan now had a
rough edged indentation where the rack had trimmed it to match the
diameter needed for clearance on torque engine rotation. That is when I
found out about his 'favour' with the washers, and had them put back in.
OK, that's the history. Now the Mystery. The car came with the stock 2
barrel. I have the complete Rootes list of all Tiger parts, by number,
and those washers are not amongst them. I have the exploded view of the
mount assembly, and clearly see the stainless heat shield, but no sign
of a washer. So the question remains, was this a PO addition, for no
apparent purpose, or an unlisted original part?
The presumed purpose of such washers would be to center the fan in the
shroud, although Rootes could have done that with the chassis motor
mount height.
Does anyone have VERIFIABLE information on this being a STOCK
configuration, as I may have been misled by the logic of the existing
received configuration that was completely stock.
I apologize, in advance, if this 'logical conclusion' was in error, and
such washers never really were stock. Although, they are a neat
solution to balance fan center, rack clearance, and air cleaner to
bonnet clearance, etc.
Steve
--
____________________________
Steve Laifman
Editor
<http://www.TigersUnited.com>
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