big end clearance

[cavman_cdx]

hi all ime new to this site (wish i found it sooner ) i am currently in the prosess of rebuilding the engine in my astra coupe 2.2 as it spun a big end shell due to previous owner running around with a cracked cam cover, the timing chain had eaten through the top guide and worn through the cam cover. by some miricle the timing dident skip and the head is in good shape. i have overhauled the head with new valve seals and re lapped the valves and a good clean etc and obtained a replacement bottom end as the the crank was gouged to hell and the con rods were black and out of round. i have decided to rebuild the bottom end aswell and have had the bores checked and honed and had the crank checked and the main and big end journals polished. i asked the shop to jot down the journal measurments and the main bering ones are well within tolerance but the big end measurements dont quite add up. according to there measurements the big end journals are 48.971 and in the hayens manual it states 49.000 for std size they told me this is ok for std size bearings is this right?? eny help on this would be appreciated

 

[vocky]

I don't know the exact figures but I know the big ends tend to wear after 50k so it's probably within spec

 

[cavman_cdx]

within spec for new std size bearings?

 

[vocky]

I would use brand new genuine bearings to get the best tolerances (about £50 the set)

 

[cavman_cdx]

yeh have been useing genuine parts (buy cheap buy twice) its the first time i have rebuilt a bottom end probably being parranoid just dont want to be doing it all again in a few miles down the road

 

[sandyc]

I got my big end bearings from a company called Trechil on Ebay. 150 miles of careful driving so far after my rebuild and no issues. Early doors yet though.

 

[cavman_cdx]

heard of them are there parts eny good ?? did you check the running clearance when building your engine?