[Fot] max. TIR for TR4 aluminum flywheel?

[J.C. Hassall]

On 3/18/2012 6:06 PM, J.C. Hassall wrote:
> Amici,
>
> What is the maximum flywheel total indicator runout you'd feel 
> comfortable with?  I was finally able to remount the Fidanza f/w on my 
> TR4 engine this afternoon, only to find that it has 0.005 TIR.  I have 
> no record on my build log of the previous runout, so I need advice.  
> Given that it's for "fast road" / autox, red line 6K (nitrided crank, 
> lightened and balanced rotating bits, PP and f/w balanced as an 
> assembly), do you think 0.005 is too much?  Since all mating surfaces 
> were clean and smooth, of course I was shooting for 0.000, so needless 
> to say I was disappointed.

As the saying goes, "Cleanliness is next to godliness, unless you're 
building an engine, then the order is reversed."  The TIR problem was 
simply due to undetectable grunge on either the f/w or the crank.  After 
vigorously wire brushing the interfaces, it went back together 
perfectly.  Since I specified 0.000 TIR in the satellite equipment I 
used to design, I figured zero was what I should have here.  And I got 
it!  Happiness is zero TIR.

Now, on to the next opportunity....

-- 
Jim Hassall
Blacksburg VA
'63 TR4 in autox preparation
99% finished, 90% to go