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!
Eric,
Don't add the oversize washer, stick with the standard set. Too little
clearance can be just as bad as too much! Some time ago they used to make a 2
1/2 thou set. I might have some back on one of the shelves here - even so that
would take you down to only 5 thou clearance. You could file the back of the
washer until you had 6, but I'd be very concerned about keeping the back side
true and square. Especially since the only thing holding those in place is the
smallest of edges up against the main bearing cap. I'd be afraid that it would
be too easy to slightly round the corner which would only help the washer to
slip past and fall out in the future. Since 7 1/2 is within spec, I'd stick
with that.
Using just a screwdriver on the crank pulley without having to measure, eyeball
your end float every time you change your oil - I find the washers will usually
stay in place avoiding major damage up to about .025" (about the same as a spark
plug gap). Much more than that and you start to run the risk of serious damage
to the block internal webbing and bearing cap as well as the crank. As long as
you're less than that you should be just fine.
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