About 5 years ago when I overhauled the 1987 B230FT in the wife.gov's 1986 745T, I was unaware of longer and shorter pistons. I was unaware of Viagra then, too. The machinist pointed out the improved piston design when I picked up the parts for assembly. This engine has no piston slap sound, and it has about 60,000 miles on it since rebuild. I do not know the make of the piston, but interestingly enough the bore was taken out to 96.8mm, which is 0.20 mm more than oversize pistons are normally available.

According to one of the Volvo mechanics I am acquainted with, Volvo did lots of warrantee work to eliminate the piston slap sound on the B230 series on engines. Mechanics spent lots of time custom fitting replacement pistons to eliminate the piston slap sound. This warrantee work stopped when Volvo went to piston oil cooling, which was at about the same time, if not exactly the same time as the pistons were lengthened.