LQ4 + 408 + 317 compression ratio?
04-03-2014, 09:42 AM
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LQ4 + 408 + 317 compression ratio? Im going to be running an LQ4 with a 408 rotating assembly in a 47 Dodge street rod. The car will be mainly a street car, so I need relative reliability and be able to run on pump gas.
Looking at heads, it seems that if I stay with the stock 317s i'm going to be around 11.5:1 compression. Is that right? Will it be okay on the street or will I need to get thicker head gaskets to reduce the compression? Is there any reason for me to try and find 243's? Won't they increase the compression ratio even more?
Looking at heads, it seems that if I stay with the stock 317s i'm going to be around 11.5:1 compression. Is that right? Will it be okay on the street or will I need to get thicker head gaskets to reduce the compression? Is there any reason for me to try and find 243's? Won't they increase the compression ratio even more?
04-03-2014, 10:20 AM
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Ill probably go with something like this assembly
http://www.calspeedperformance.com/p...mbly%20ls2.htm
With the "Wiseco 4.030 bore, 6.125" rod,4.00" stroke, -3cc dish, 11.8:1 CR w/65cc heads" which says its 11.8:1. So since my 317's are 70cc, what will my ratio be....around 11.5?
Also, since these are dished pistons, wouldnt flat top pistons increase the compression ratio even more than that?
http://www.calspeedperformance.com/p...mbly%20ls2.htm
With the "Wiseco 4.030 bore, 6.125" rod,4.00" stroke, -3cc dish, 11.8:1 CR w/65cc heads" which says its 11.8:1. So since my 317's are 70cc, what will my ratio be....around 11.5?
Also, since these are dished pistons, wouldnt flat top pistons increase the compression ratio even more than that?
