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2015+ S550 Mustangs
2015+ S550 Mustang Talk
What happened to a significantly smaller and lighter 2015 Mustang?
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<blockquote data-quote="thePill" data-source="post: 13861149" data-attributes="member: 119504"><p>Push-Rod engines are riddled with parasitic loss, thus, a larger displacement is required to contend with Over Head Cams. The reason pushrod engines cannot rev high is due to valve float and the inefficient action of the push rods themselves. Even the mighty LS7 has horrible valve float... OHV engines are basically forced to produce power at a lower RPM, they just lose power once the RPM's raise, friction from the push rods invite parasitic losses AND, the inefficient action of those rods translate to poor valve control and valve float...</p><p></p><p>Chevy needs to go DOHC... But they are stuck now after investing $820 million dollars into the LT1 program. They could have engineered a great 4.5-5.5 liter DOHC for the same cost... Even now, DOHC R&D cost have sunk below the OHV engines due to widespread, worldwide use.</p><p></p><p>The complexity of Variable Valve Timing in an OHV is also slightly greater than the TiVCT in a DOHC. This VCT technology is key to the survival of the V8.</p><p></p><p>Total valve area in a DOHC is twice the size of a 2 valve pushrod. Say a large 2.02 intake valve compared to the dual intake valves of a Coyote... The total area is almost 3 inches compared to the 2 of a heavy OHV. You have to shim some OHV heads because of this...</p><p></p><p>Engine weight: The Coyote 5.0 now weighs less than Chevy's new LT1. The Coyote is 429lbs wet, ready to run. The LT1 took on 30-40lbs over the LS3 (418lbs), about the same as the LS7 (450lbs). All advantages have been lost...</p></blockquote><p></p>
[QUOTE="thePill, post: 13861149, member: 119504"] Push-Rod engines are riddled with parasitic loss, thus, a larger displacement is required to contend with Over Head Cams. The reason pushrod engines cannot rev high is due to valve float and the inefficient action of the push rods themselves. Even the mighty LS7 has horrible valve float... OHV engines are basically forced to produce power at a lower RPM, they just lose power once the RPM's raise, friction from the push rods invite parasitic losses AND, the inefficient action of those rods translate to poor valve control and valve float... Chevy needs to go DOHC... But they are stuck now after investing $820 million dollars into the LT1 program. They could have engineered a great 4.5-5.5 liter DOHC for the same cost... Even now, DOHC R&D cost have sunk below the OHV engines due to widespread, worldwide use. The complexity of Variable Valve Timing in an OHV is also slightly greater than the TiVCT in a DOHC. This VCT technology is key to the survival of the V8. Total valve area in a DOHC is twice the size of a 2 valve pushrod. Say a large 2.02 intake valve compared to the dual intake valves of a Coyote... The total area is almost 3 inches compared to the 2 of a heavy OHV. You have to shim some OHV heads because of this... Engine weight: The Coyote 5.0 now weighs less than Chevy's new LT1. The Coyote is 429lbs wet, ready to run. The LT1 took on 30-40lbs over the LS3 (418lbs), about the same as the LS7 (450lbs). All advantages have been lost... [/QUOTE]
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What happened to a significantly smaller and lighter 2015 Mustang?
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