383/388 Chevy stroker
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ARP [http://www.summitracing.com/parts/arp-134-6027 part number 134-6027] is for a set of rod bolts with additional clearance at their heads to help cam to rod clearance problems. They are for use with a factory 5.7" rod or the equivalent. | ARP [http://www.summitracing.com/parts/arp-134-6027 part number 134-6027] is for a set of rod bolts with additional clearance at their heads to help cam to rod clearance problems. They are for use with a factory 5.7" rod or the equivalent. | ||
| − | ===Crankshaft to block=== | + | For clearance, I-beam rods are much easier to use than H-beam rods. |
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| + | ===Crankshaft and rod to block=== | ||
| + | [[File:383 pan rail.jpg|thumb|350px||Bottom of block clearanced for rod nut]] | ||
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The places for clearance problems between the crank and block is at the bottoms of the cylinders and the pan rails. If any metal has to be removed, remove the least amount needed, or else the water jacket could be hit. | The places for clearance problems between the crank and block is at the bottoms of the cylinders and the pan rails. If any metal has to be removed, remove the least amount needed, or else the water jacket could be hit. | ||
| − | Same thing here as was said above, regarding stroker rods. They will have a much better chance of having enough clearance without any modifications to them '''or''' the block. The place where the rod hits is the nut (if a nut and bolt rod big end) or the capscrew. Grinding on either can be an iffy proposition, so only remove what's absolutely necessary and not a bit more. If using the stock SBC 400 rod (5.565"), it will not need any clearancing. But 383 stroker cranks that use the 400 rod are not that readily available and the rod length-to-stroke ratio is not favorable. | + | Same thing here as was said above, regarding stroker rods. They will have a much better chance of having enough clearance without any modifications to them '''or''' the block. The place where the rod hits is the nut (if a nut and bolt rod big end) or the capscrew. Grinding on either can be an iffy proposition, so only remove what's absolutely necessary and not a bit more. If using the stock SBC 400 rod (5.565"), it will not need any clearancing. But 383 stroker cranks that use the 400 rod are not that readily available and the rod length-to-stroke ratio is not favorable. |
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==A word on rod/stroke ratios== | ==A word on rod/stroke ratios== | ||
Most SBC engine builders agree the 5.565" rod/3.75" stroke ratio is borderline unacceptable at 1.48:1. For comparisons sake, a stock SBC 350 has a ratio of 1.64:1, and the 6" rod 383 stroker is at 1.6:1. The SBC 302 rod/stroke ratio is 1.9:1. It is generally thought that a ratio of 1.5:1 to 1.55:1 is about as low of a rod/stroke ratio that should be used in a performance build that will redline at 5500 rpm or more. | Most SBC engine builders agree the 5.565" rod/3.75" stroke ratio is borderline unacceptable at 1.48:1. For comparisons sake, a stock SBC 350 has a ratio of 1.64:1, and the 6" rod 383 stroker is at 1.6:1. The SBC 302 rod/stroke ratio is 1.9:1. It is generally thought that a ratio of 1.5:1 to 1.55:1 is about as low of a rod/stroke ratio that should be used in a performance build that will redline at 5500 rpm or more. | ||
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| + | BTW, this has little to nothing to do with making or not making power. The rod ratio concern in '''this''' case is a matter of frictional losses and side loading caused by a too-short rod more than a horsepower or two possibly gained from a longer rod. | ||
==Aftermarket parts combos== | ==Aftermarket parts combos== | ||
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