main bearings with twin drillings

[andrewp]

On the turbo 1.6 DOHC some of the five main bearing half shells have twin holes (one of which is for the oil squirter to cool the piston's underside). No aftermarket main bearing set -that I have yet to locate- has the twin holes that the turbo M100 requires. On "Isuzone" Impulse RS owners are using normally aspirated 1.8 and 1.6 main bearings by drilling the extra hole via a jig. Seems a slight risk.

Anyone have a source of the proper main bearings?

[bobbrown]

There is another thing with the after market bearings and that is there appears to be only one size for the standard diameter crank but Isuzu list different grades
Main bearings there are 4 grades and big ends 3 grades this is due I think to machining tollerances on the journals so to maintain the correct clearance Isuzu made graded bearing and it's the same for standard pistons. It is also worth noting the clearance are very small as the range covers 0.013mm or 0.008"
I did find a site in the US that lists all the main bearing grades for $40.43 a set so you have the option of green, brown, black and blue but will need to know what size you need.

[racerstev]

Be careful on the rod bearings as well, some don't have room for the large fillet on
the forged turbo crank. I thnk the brand was "Rock" not to be confused with Rock Auto....