Thread: Suggestions from the sbc guru's

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We[[, It looks like with those restrictions put on engine construction you will mainly be trying to get rid of horsepower thieves like friction and power robbing accesories, by this I mean high volume oil pumps. Stay with the stock style pump for pressure and oil volume. Next you will have to do a real exact blueprint and probably a lot of machining to get the right clearances. You will probably be able to run a modified winged sump, I suggest a "canton"
Crankshaft scraper and rear baffle to keep the oil off the crank. Plugging the oil drainback holes on cam gallery area with plugs or grub screws and drilling a 1/8 hole in them. This stops oil from falling onto the crank but still leaves enough to oil around the lifters and cam lobes. restricters in the lifter oil gallerys to keep a resonable amount of oil in the sump, especially in the turns !!!!. Blueprint your rods from good chevy castings good arp Bolts and shoot peening the rods, helps them live. Now here is a good trick for you crankshaft. Get your Iron or steel crank and grind it down to the smallest bearing daiameter there are 2 advantages, you want a rounded radius in the corners of the journal, this prevents a cracking sorce. It also makes the bearing surface smaller so it cuts down on friction. Some of the chevy intakes were aluminum spreadbores. rarer ones were the LT1 and Z28 Holley 4 barrels pricey but if the rules allow them and are not rigidly requiring you to stick with the cast iron, you can pick up some horsepower here. If you are stuck with the cast iron manifold you can radius the edge under the carbutettor pad where the plenum has that right angel turn into the runners, this smooths out flow and increases flow velocity through the runners and into the intake ports.
Fasteners especially nuts and bolts on the intake manifold get the stainless bolts as these have a lower level of Heat transfer through them and into the manifold and fuel air mix. Heat shields right along the bottom of the manifold to keep the hot oil off. Ceramics on the pistons, heads, ports, and top and bottom of the manifold to keep the heat where it should be and out of the manifold. Of coarse you use very effective heat shielded intake gaskets with the heat riser blocked off. Fuel heat control, use a wide stainless steel flat plate under the carburettor to keep the heat soak out of the carburettor and fuel. Check the rules and see if you can run a cool can, if you can dont just use ice, use dry ice. We usually start the engine have it running, and just before you head out onto the track dump the dry ice into the can then and slam the slid shut. Run stainless fuel line wrapped in insualation to keep fuel cool. You should be able to run a carb spacer, this helps horsepower in high revs. same for multi angle valve seats, and backcutting the valves. Cutting the valve stems to a smaller diameter to lighten them and running the crower H5 springs, they conrol the valve train with less seat open pressure, thus saving horsepower. So really a lot of it is how much you can modify the parts, and what the scutineers allow. And of coarse you have to tear the motor down for them too, so they can do a quick trackside check if you are constantly out front. Then a lot of it is how you set up your car and it's suspension and what the rules allow there. I have not mentioned mechaical cam grinds because is the track short or long oval track ? one other trick is to have an on off toggle switch on the exciter wire to your alternator, when racing, after the flag goes up turn off the power to the alternator, this gives you a bit more power to the rear wheels. turn it back on when the caution light is on and when driving back into the pit area, so this should keep you busy in the office.