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<blockquote data-quote="99svtvert" data-source="post: 5505575" data-attributes="member: 22962"><p><a href="http://web.mac.com/steve40/Site/Performance_stock.html" target="_blank">http://web.mac.com/steve40/Site/Performance_stock.html</a></p><p></p><p>Excerpt from maker;</p><p></p><p>"Testing was completed on a ’99 Cobra engine that was rebuilt with ported heads and intake. Oliver rods and Ross pistons (8.9:1) designed for big boost. The factory .393-inch lift cams were replaced with hotter .486-inch lift cams that also have a bit more duration. Additionally, the engine is equipped with a Paxton blower, but the unit was left disconnected during testing so the results would be closer to what owners might see on a stock or mildly modified engine.</p><p> </p><p>To get the test going the engine was run on the Superflow 901 with the stock valvetrain. Moyer ran quite a few tests and most of the pulls were made between 4,000 and 7,000 rpm. The engine made just over 360 horsepower all through the 6,200-6,400 rpm range. Torque was in the 340 range between 4,400-5,100 rpm. The best numbers we observed were 366.8 hp at 6,300 rpm and 345.9 lb-ft of torque at 5,000 rpm.</p><p> </p><p> Moyer and Hunsberger then removed the cam covers and installed the roller rockers and solid lifters. Lash was set to .003-inch for the intake and the exhaust. Moyer used a feeler gauge and made the adjustment with the gauge between the cam lobe and roller, not between the valve tip and roller, as is conventionally done with a pushrod engine. The reason is because the rails on the roller spool (for the valve) are too narrow to fit a feeler gauge. Moyer says that .003-inch lash between the cam and roller actually equals .007-.008 at the valve tip.</p><p> </p><p>The Cobra engine was buttoned up and tested again, with almost unbelievable results. Power was immediately, jumping to the 390 range between 6,000-6,2000 rpm, and with the torque following suit with a bump up to the 370s between 4,800-5,100 rpm. Peak horsepower was now 392 at 6,200 rpm and peak torque was 375 at 5,100 rpm. At the highest point we observed a gain of 40 lb-ft of torque at 5,800 rpm.</p><p> </p><p>“I figured the engine would pick up about 10 hp and I would have been elated with that,” says Moyer, who was really just looking for more reliability. “But it picked up over 40 hp at the top of the range.”</p><p> </p><p>Like we said, the gains in power are almost too good to be true, but the before and after dyno testing proved otherwise. We learned that anything can happen when it comes to valvetrains, especially when you design and install something that is better than stock. To date, we’re unsure as to whether anyone else has attested an aftermarket valvetrain on a Modular engine, but it appears that there’s plenty of untapped performance and this makes us wonder what else there is to uncover with a little R&D".</p></blockquote><p></p>
[QUOTE="99svtvert, post: 5505575, member: 22962"] [url]http://web.mac.com/steve40/Site/Performance_stock.html[/url] Excerpt from maker; "Testing was completed on a ’99 Cobra engine that was rebuilt with ported heads and intake. Oliver rods and Ross pistons (8.9:1) designed for big boost. The factory .393-inch lift cams were replaced with hotter .486-inch lift cams that also have a bit more duration. Additionally, the engine is equipped with a Paxton blower, but the unit was left disconnected during testing so the results would be closer to what owners might see on a stock or mildly modified engine. To get the test going the engine was run on the Superflow 901 with the stock valvetrain. Moyer ran quite a few tests and most of the pulls were made between 4,000 and 7,000 rpm. The engine made just over 360 horsepower all through the 6,200-6,400 rpm range. Torque was in the 340 range between 4,400-5,100 rpm. The best numbers we observed were 366.8 hp at 6,300 rpm and 345.9 lb-ft of torque at 5,000 rpm. Moyer and Hunsberger then removed the cam covers and installed the roller rockers and solid lifters. Lash was set to .003-inch for the intake and the exhaust. Moyer used a feeler gauge and made the adjustment with the gauge between the cam lobe and roller, not between the valve tip and roller, as is conventionally done with a pushrod engine. The reason is because the rails on the roller spool (for the valve) are too narrow to fit a feeler gauge. Moyer says that .003-inch lash between the cam and roller actually equals .007-.008 at the valve tip. The Cobra engine was buttoned up and tested again, with almost unbelievable results. Power was immediately, jumping to the 390 range between 6,000-6,2000 rpm, and with the torque following suit with a bump up to the 370s between 4,800-5,100 rpm. Peak horsepower was now 392 at 6,200 rpm and peak torque was 375 at 5,100 rpm. At the highest point we observed a gain of 40 lb-ft of torque at 5,800 rpm. “I figured the engine would pick up about 10 hp and I would have been elated with that,” says Moyer, who was really just looking for more reliability. “But it picked up over 40 hp at the top of the range.” Like we said, the gains in power are almost too good to be true, but the before and after dyno testing proved otherwise. We learned that anything can happen when it comes to valvetrains, especially when you design and install something that is better than stock. To date, we’re unsure as to whether anyone else has attested an aftermarket valvetrain on a Modular engine, but it appears that there’s plenty of untapped performance and this makes us wonder what else there is to uncover with a little R&D". [/QUOTE]
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