On the issue of end float of the crank, after replacement of the thrust washer,
it does not matter how much was the thrust washer face on the crank turned
down. Remember, the determining distance is that from the main bearing caps to
the thrustbearing face on the crank itself. Thus, when you add thickness to the
thrust bearing in order to provide correct end-float, regardless of the wear on
the crank face, you achieve the correct positioning of the crank in relationship
to all parts of the engine, including the connecting rods and their matching
journals on the crank.
Cheers.
Eric Conrad wrote:
> After all the banter about 'non-triumph' stuff, and with many people
> scrambling to "unsubscribe", I'm hoping I'm not just sending this into the
> proverbial "concert hall", with only the crickets to hear my question. I
> really do need some advice.
>
> I'm reassembling my engine. Prior to disassembly (several months ago), the
> end float was terrible. I seem to remember it being between 0.015" and
> 0.020" prior to machining the engine and crank. Tonight, after I replaced
> the mains and added STD thrust washers, I checked the crank end play -
> wanting to do this before I go any further.
>
> Both my Bentley and Haynes manuals say that the acceptable range for the end
> float should be 0.006" and 0.008". These figures are primarily mentioned
> for checking the end float for a run-in engine, while the engine is still in
> the car. I'm assuming that my rebuild should also be within the same
> tolerances, as no other data is provided for a fresh engine's end float. As
> I measured my end float several times, I constantly got a reading of
> 0.0075". Is this too close to the upper tolerance limit that I should add
> one 5-thousanths oversized thrust washer along with keeping one standard
> thrust washer in place? (I understand that 5-thousanths is the smallest
> oversized thrust washers.) If I should add the oversized thrust washer, I'm
> figuring my end float would be approximately 0.0025". Is this too little
> movement?
>
> In a related question, does anyone have thoughts about control rod
> positioning, as affected by the thrust washers? In other words, is it
> possible to have the conrod journals either too far forward, or too far
> rearward, and still be within the specifications of 0.006" and 0.008"? This
> will be my concern if I do have to add a 5-thousanths oversized thrust
> washers.
>
> I guess lastly, I'm following the manual instruction for bolting the main
> caps, and including lock washers to keep the bolts from backing out. I've
> also added BLUE loc-tite. It seems to me that I've read a thread on this
> list lately that stated that lock washers should not be used, and that
> loc-tite is sufficient to hold the bolts. Any thoughts before I get too
> far?
> Thanks all,
> Eric Conrad
> '76 TR6 - engine rebuild began tonight, and went late into the morning -
> non-stop! Ugh!
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