carolinaflare
Contributing Member
1998 60 Deg 90HP Loop Charge J90SLECM
Hello all, Quick question regarding replacement piston brand and size.
I am rebuilding my motor due to low compression on 2 out of 4 cyl. I know what caused the compression problems and have fixed it, (previous owner sank it). I have stripped the block and had all 4 cylinders machined .020 over original to remove scratches and blemishes. The outboard machine shop guy told me that if i plan on using Wiesco replacement pistons it should be machined 1/2 a thousanth bigger than the book requirement to allow for the forged Wiesco piston to "swell". I agree judging by his experience and the overwhelming talk about this online.
My question is- The block has now been machined to .020+ 1/2 a thousandth. I have found a new set of .020 oversized pistons that are OEM J/E , not wiesco. Would it be safe to put those pistons in the motor instead of the wiescos? the manual shows a +/- .004 tolerance for bore size so im thinking that the .0005 of an inch isint that big a deal. The reason for picking the OEM pistons is totally price, I can get them new through a buddy of mine for about 40$ each, vs 110$ each for the wiesco.
Thanks for the advice.
Tyler
Hello all, Quick question regarding replacement piston brand and size.
I am rebuilding my motor due to low compression on 2 out of 4 cyl. I know what caused the compression problems and have fixed it, (previous owner sank it). I have stripped the block and had all 4 cylinders machined .020 over original to remove scratches and blemishes. The outboard machine shop guy told me that if i plan on using Wiesco replacement pistons it should be machined 1/2 a thousanth bigger than the book requirement to allow for the forged Wiesco piston to "swell". I agree judging by his experience and the overwhelming talk about this online.
My question is- The block has now been machined to .020+ 1/2 a thousandth. I have found a new set of .020 oversized pistons that are OEM J/E , not wiesco. Would it be safe to put those pistons in the motor instead of the wiescos? the manual shows a +/- .004 tolerance for bore size so im thinking that the .0005 of an inch isint that big a deal. The reason for picking the OEM pistons is totally price, I can get them new through a buddy of mine for about 40$ each, vs 110$ each for the wiesco.
Thanks for the advice.
Tyler