Jeff
According to my copy of the TR4 workshop manual (Triumph edition)
The 'Big end bore' is 2.2327 - 2.2335 ins or 56.71-56.73 mm.
The bearing manufacturing clearances are 0.0028 -0.0040 ins or 0.071-
0.1016 mm
The wear limit is 0.005 ins (0.127 mm)
Hope this helps !
--
Cheers
Brian Johnson (UK)
1963 TR4 AFP 503A (UK) / IZS 733(USA) - CT27216-L (now not L but O )
1954 TR2 46 BHX TS554-O UK Car in pieces
1989 Vauxhall Cavalier 2.0 GLI - Eurobox but it goes !
Internet b.johnson@lycosmail.com
New website http://websites.diamond.co.uk/~b.johnson/index.htm
Jeff A Williamson wrote:
>
> I received my crankshaft from the machine shop, and my new bearings from BPNW.
> I seem to be having a clearance problem between the connecting rod bearings
>and
> the crankshaft. The more rods I tighten down, the more increasingly difficult
> it becomes to turn the crankshaft (the head is still removed). If all 4 are
> torqued down to spec, I cannot turn the crankshaft at all by hand. If all 4
> rods are tightend to only about 15 lbs each, the crank turns fairly easily.
> I've tried torqueing the rods in different sequences, and the result is still
> the same. I also made sure the the caps went back onto the same rod from which
> they came.
>
> The machine shop turned the crankshaft main and rod journals to the .010 spec
> listed in the manual. I purchased .010 bearings to match. The clearance of the
> main bearings seem to be fine, as the crank will rotate with little effort
> without the rods attached, and doesn't seem to be loose. I checked the
> crankshaft connecting rod journals with a micrometer, and the reading is right
> on at the large end of the spec. listed in the manual. I checked the
>difference
> between the thickness of an old rod bearing and a new rod bearing. This
> difference is .007". This would mean that the total difference accross the
> diameter of the big end of the rod with the bearings in place is .014" (.010
> for the size on the new ones and .004" for wear on the old ones, if I've done
> the math correctly). This is a little puzzling as the old bearings showed
> little sign of wear (I think this engine had been rebuilt shortly before it
>was
> retired 14 years ago).
>
> Tonight, I plan to check the clearance using plasti-gauge, and I'll mic
> everything again just to make sure. What have I missed? Should the crankshaft
> be so difficult to turn? Is there something else I should be looking for? Has
> anyone else experienced a similar problem?
>
> For those of you who have something other than a Haynes TR2-4A repair manual,
> what does it show for the std. connecting rod journal diameter?
>
> Jeff Williamson
> '58 TR3A
> '60 TR3A
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