557 vs big cubic inches
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02-03-2013, 02:38 PM
#12
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Thread Starter
I had forgotten about this thread.... Thanks for bringing it back to the top
Thanks for the compliment coolerman, Parnell did a great job on it
My engines were originally 632's ci, I had always thought that the bigger ci was better for torque, and might still b true for a N/A engine. But the more I look into it there is more to it with the blown engines, and having a solid bottom end is essential when making big hp.
I've never been a big believer in revving engines into the 6-6500 rpm range for no better reason than maybe just not used to it --and more chance In my mind to fail.
Thanks for the compliment coolerman, Parnell did a great job on it
My engines were originally 632's ci, I had always thought that the bigger ci was better for torque, and might still b true for a N/A engine. But the more I look into it there is more to it with the blown engines, and having a solid bottom end is essential when making big hp.
I've never been a big believer in revving engines into the 6-6500 rpm range for no better reason than maybe just not used to it --and more chance In my mind to fail.
03-26-2013, 01:08 PM
#13
as stated, the 557 is the best combination for reliably its a combination of shorter stroke and longer rod that gives it the wiining edge, a rod ratio of 1.5 x stroke is desired minimum requirement when building one of these blower monsters!! (1100/1200 hp...) this is my professional opinion, others may say different, but I want my sh*t to live!!!
03-26-2013, 01:21 PM
#14
I've seen many engines built by various engine builders utilizing rod and stroke combinations that are "way out there" in thought... it's really simple when one thinks of what's actually going on inside the engine... the pin height should be comfortable, in other words not crammed up the pistons butt!! when the pin is way into the oil ring, it is subject to an extreme level of heat and limited cooling effect from oil spray, even with the use of bottom end oil spray rails, the piston,pin, and rod bushing life is severly diminished... the use of thermal barriers (coating) helps, but in no way eliminates this condition, the only way is the right way, keeping the pin at a comfortable distance away from the heat!!! again, IMPO
03-26-2013, 01:29 PM
#15
the "perfect" combination is 4.375" stroke with a 6.635 (.500") long rod.. coupled with a 4.500 bore will give you the "557" this recip assembly in a 10.200 block will allow for a compression height of 1.370 allowing sufficient room to square deck the block for blueprinting purposes...
