mains shells, centre thrust won't fit
Discussion
I am just starting my engine build, and have got off to a flying start - not!
First job was to check the clearance on the main bearing shells using plastigauge. Having cleaned up the block and crank, and with the engine mounted on a stand, I pressed the lower shell halves into the block and lubed them with assembly lube. I then lubed the main journals aswell, and lowered the crank into the block.
It jammed.
The crank would not press down onto the centre cap - the one with the thrust plates on the sides. I pulled the crank back out and popped the shell out. It was badly marked at the corners, and quite obviously was way too wide to fit onto the crank. I tried the lower shell half - it falls onto the crank with no effort; it is measurably narrower than the upper shell half. I've just removed these shells from sealed packaging, so they are as they came from the manufacturer.
I haven't measured it but we are talking about over 1mm difference in the width of the two halves of the shell.
Something is wrong here surely? Why would the shell halves be different widths? Has one not been machined properly or something?
It's Saturday afternoon and the supplier is closed unfortunately, but I will be ringing them on Monday. In the meanwhile is this something anyone else has come across?
First job was to check the clearance on the main bearing shells using plastigauge. Having cleaned up the block and crank, and with the engine mounted on a stand, I pressed the lower shell halves into the block and lubed them with assembly lube. I then lubed the main journals aswell, and lowered the crank into the block.
It jammed.
The crank would not press down onto the centre cap - the one with the thrust plates on the sides. I pulled the crank back out and popped the shell out. It was badly marked at the corners, and quite obviously was way too wide to fit onto the crank. I tried the lower shell half - it falls onto the crank with no effort; it is measurably narrower than the upper shell half. I've just removed these shells from sealed packaging, so they are as they came from the manufacturer. I haven't measured it but we are talking about over 1mm difference in the width of the two halves of the shell.
Something is wrong here surely? Why would the shell halves be different widths? Has one not been machined properly or something?
It's Saturday afternoon and the supplier is closed unfortunately, but I will be ringing them on Monday. In the meanwhile is this something anyone else has come across?
prtvr said:been there? I host it! Thanks anyway!
Hi
Have you been to this web site, on rebuilding a rover V8.
http://interweb4u.com/griff500
Phil
Found thison RPi's site:
Looks like I have some elbow grease to burn!
RPI said:
All oversize bearings have oversized thrusts, therefore the crank end float must be adjusted on no 3 ( center) end cap. To do this - take 2 pieces of 1000/1200 emery paper and a flat surface ie glass. Rub down thrusts equally on both sides until a clearance of 6-14 thou is achieved.
Looks like I have some elbow grease to burn!
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