Used Parts Play - Performance Questions and Answers

Performance Q&A

Kevin McClelland Nov 1, 2006 0 Comment(s)

A When building a performance stroker engine you should mock up the rotating assembly several times before the final assembly. This is where you will find these little surprises like the rods hitting the camshaft, the pan rail, or the oil pan, piston-to-valve clearance issues, and other fun things. Any of these problems will require some type of clearancing, and you wouldn't want to do any of them with a freshly cleaned, ready-to-assemble engine. Installing a 3.75-inch stroke crankshaft in a 350 block brings 5.7-inch-long rods in very close proximity to the cam lobes and the pan rails. The 400 small-blocks used a special 5.565-inch-long rod that had a specially profiled big end. In a small-block buildup, cylinder Nos. 1, 2, 5, and 6 are always the closest. This is due to the camshaft lobe phasing. With the rotating assembly, you will need at least 0.050 inch of clearance between it and any other components. With your Eagle capscrew-type rod, it's very easy to clearance the rod to clear the camshaft. Unfortunately, you have probably already balanced your rotating assembly. Whatever you take off of the four rods listed above, you will also want to remove the same amount of material off the rest of the rods. This will keep your balance as close as possible.

Sorry that we don't have an easier answer. Unless the rods are specifically designed for stroker applications, you always have to clearance the rods for the camshaft in a 383 combination. Good luck.

Tired Monte Q I have an '86 Monte Carlo SS that I bought new. It's been my daily driver off and on for 20 years, and now has over 230,000 miles on it. It's getting pretty tired, and I want to replace the 305 with a crate 350. I still have to pass an emissions test annually. I've spoken to the local dealer and they tell me I have to replace it with another 305. I know other people have put 350s in their cars and still pass emissions. Can you tell me a part number for a crate engine I can put in that will keep the sniffer happy? Thanks for your advice.Bill WivelSahuarita, AZ

A You know that the dealer is going to say "Stock is right!" Most of the OEM dealers don't want to deviate from stock because of emissions laws (and their poor understanding of what will actually pass emissions). Let's put a package together.

We would start with the original GM Goodwrench 350 crate engine. They have sold millions of these engines over the years, and it's a great foundation for performance builds. This long-block engine, PN 10067353, is the replacement engine for all '79-and-earlier passenger cars. It is built from all-new components that spec out at 8:1 compression, 1.94/1.5-inch valves, 76cc chamber iron heads, cast crankshaft, four-bolt mains, and cast-aluminum pistons. On the engine dyno, equipped with the stock Q-jet manifold, Q-jet carb, cast-iron exhaust manifolds, and dual exhaust, the engine produces 230 hp at 4,500 rpm, and 330 lb-ft of torque at 3,200 rpm. This is a dead-stock 350 that will easily pass any emissions test Arizona wants to throw at your Monte Carlo.

As I said, this engine is a great foundation for a mild-performance engine. We would install an Edelbrock 3701 Performer manifold equipped with provisions for the EGR valve, an Edelbrock Performer camshaft originally designed for the LG4 305 engine back in the mid-'80s. This cam is specifically designed to work with the factory computer-controlled system and the computer-controlled Q-jet carb on your Monte. It's sold under PN 3702 and specs out at 194/214 degrees duration at 0.050 inch tappet lift, 0.398/0.442 inch max lift, and is ground on 112 centers. Yes, this is a very mild camshaft; however, it builds great torque with the low-compression 350. To round out your package, go with a set of Edelbrock TES headers. They offer a tubular exhaust system that fits the H.O. Montes with the high-flow four-bolt catalytic converter. This header system is sold under PN 68793 and will bolt right into your Monte if you upgrade to the high-flow converter. With this package listed above, your engine will step up to 275-plus horsepower and over 350 lb-ft of torque, and it will make great power from idle to 5,000 rpm. The best part is that the smog police won't even know that the long-block has been touched. All components of this build have been certified by the California Air Resources Board.Source:


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