>
>Does anyone know what the piston clearance should be on a freshly
>bored TR-6? The Bentley manual is not all that clear on the subject;
>gives lots of specs,i.e. piston grades F, G & H major diameters, bore
>sizes, etc. From that info I calculated a piston wall clearance in a
>stock motor to be between .0025" - .0028". This looks a little on
>the 'tight' side for a motor of this vintage, I was expecting .004"
>or so.
>
>Anyone out there have a 'definiatve' answer?
>
>Thanks
>Steve Sutton
Steve,
You're about to get a hundred different answers, but I just bored a 72
TR6 engine. New Hepolites, all graded "A" according to spec. Not more
than .000125 over minimum spec.
Fitted each piston at 2.94250. +/- .00005
Cylinders bored at 2.94550 +/- .00005
Everything I could determine indicated .004 bore larger than piston diameter.
I went .003
How did you arrive at F<G & H grades?
Normally if a piston is graded "C", it's too sloppy for spec use even in
over bore.
If you have a Bentley manual, I would suggest you take a look at page
101 for spec and grading.
Now that I have you thoroughly confused, I'll leave you ...
Best Regards,
Tony
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