THE SHOP

Performance & Hotrod Business - July '15

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PRECISION ENGINE 12 n PRECISION ENGINE n July 2015 the crank. If not timed cor- rectly relative to the crank's rod throws, the engine either won't fire at all or it will run so out of time that it'll be worthless. Removal/Installation The reluctor wheel (also referred to as a timing wheel or tone wheel) is interfer- ence-fit onto the rear of the crankshaft, with no key or other registering device. If for some reason you need to remove the wheel, (if the wheel is damaged, which is rare; or if the crank journals are to be re- ground or repaired and the wheel is in the way), first mark the wheel and the crank to create matchmarks. The position of the wheel is critical. Do not attempt to remove the wheel with a puller, since you'll bend/distort the flimsy wheel. Instead, carefully and evenly heat the wheel with a torch to roughly 200 degrees. As the wheel expands as a result of heat, it can easily be pulled off by hand, (obviously you'll need to wear heavy weld- er's gloves). This can also be done in an engine rebuilder's cleaning oven if you have access to this equipment. The reluctor wheel features a series of teeth that provide crankshaft position sig- nals (via a sensor) to the ECM. The wheel press-fits to the rear of the crank, imme- diately forward of the No. 5 main bear- ing. The wheel features about a 0.007-inch interference fit. Since LS cranks feature no keyway or other index point (thanks a lot, GM!), how do you know where to locate the wheel? Luckily, aftermarket indexing tools are available, such as the unit developed by Goodson Shop Supplies that we're featur- ing in this article. It offers a handy and absolutely essential indexing and installa- tion tool for LS reluctor wheel mounting. The RRJ-350 Reluctor Ring Jig is com- prised of a short steel tube that's equipped with two indexing pins. An external tang secures a threaded stud, with the stud tip turned down to 8mm diameter. This pin engages into the single 8mm indexing hole in the reluctor wheel. An internal guide pin (a threaded stud with the tip turned down to 11mm) engages into the 11mm blind dowel hole in the crank's flywheel flange. This jig orients the reluctor wheel precisely in the correct tim- ing position. The two dowel studs feature jam nuts to allow depth adjustment, (you simply want to make sure that the 8mm dowel passes through the wheel's 8mm hole, and that the 11mm dowel projects out far enough to engage into the crank flange dowel hole). Making the Job Easier For purposes of this article, I performed a sample installation. First, I lightly cham- fered the entry hole of the reluctor wheel, and lightly chamfered the edge of the crank's reluctor wheel flange. Goodson's instructions advise this chamfering to ease installation. The instructions also state that the wheel may be pressed onto the crank or heated to 450 degrees for a slip-on fit. Attempting to cold-press the wheel onto the crank can be tricky, since maintaining a square alignment of the wheel to the crank may be difficult. Preheating the wheel (resulting in the center hole expanding) makes the job easier and easier to control. I heated the reluctor wheel's I.D. lip with a torch, slipped the wheel onto the Here's a view of a Lunati 4.000- inch stroker crank positioned onto the block's upper main bear- ings. Notice the tone wheel at the far right in this photo. The tone wheel features an interference fit of about 0.007 inches onto the smooth outer surface of the crankshaft's rear flange. Make sure that the crank flange is clean and free of burrs. Do not attempt to "make the job easier" by grinding mate- rial from either the crank flange or the inside edge of the wheel's center hole.

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