Exhaust Manifold Mounting Kit
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Comments about Sierra 18-8502 Exhaust Manifold Mounting Kit:
I purchased a set of Sierra exhaust manifolds, risers, and two of these mounting kits for a small block GM motor (Volvo 570A). All of the studs in both of these kits are at least a 1/2 inch too short. And I was scatching my head when I opened the box and noticed the studs came with thick nyloc nuts AND lock washers. There isn't enough threads left on the stud to even engage the nylon band! And generally - and I'm basing my opinion on the fact that not only am I a licensed A/P mechanic but an ASE certified auto mechanic - you don't use split type lock washer with nyloc nuts, only flat washers. And you don't use nylocs on exhaust manifolds, you use compression nuts, and again, with flat washers, not lock washers. I ended up having to use the old bolts when I installed the manifolds. Small block GM motor, Sierra manifolds and their bolt kits - everthing should have worked, right?
Another problems I noticed; when the threaded holes were cut in the manifold for the four riser bolts, apparently they were cut with a worn-out die. When I went to torque the new riser bolts, which my Seloc manual recommends 12 to 18 foots pounds, one of the bolts stripped at the first pass of 10 foot pounds. When I pulled the bolt back out not only did I noticed it was about 1/4 shorter than the old bolts, it had only screwed in about two or three threads when it stripped. And the bolt head was bottomed. Wondering why it would strip at only 10 foots pounds I found NONE of the new bolts would thread into the manifold holes more than a turn or two by hand and all of the holes had to be chased and cleaned with a bottoming tap. After chasing the holes everything was fine. In my mind that shouldn't have needed to be done with new parts.
So save your $80 if you're planning to use these kits. Since I tore one of the boxes opening it and had to use the gasket out of it, that gasket ended up costing me $40, the cost of the kit. The other one is going right back to West Marine for a refund!
If Sierra marine is having quality control issues like this I'll take my business elsewhere!