maroonls1z

I am trying to finish up my 434 ls7 but ive come to an inpass with my DCR vs quench.
I have a zero decked ERL 434
4.155 bore
-3.0cc dished pistons
factory volume heads (70.0cc)
and a katech torquer 116 cam

ideally for quench i need to run a 0.041 head gasket but that brings my SCR to 11.82:1. I am not exactly sure what that will bring my DCR to with this cam because im not sure how to calculate it but i believe its close to boarder line for running 91 octane pump fuel. Can anyone help me calculate the actual number and then I can determine what to do. Currently i have a set of 0.051 head gaskets with 4.16 bore making my SCR a little under 11.6:1 but that leaves my quench high. Is 0.051 too high?

KCS

iTrader: (20)

There should be several online calculators available to help you out, but you are going to need to know the cam specs.

1989GTA

Exactly, you need to know the specifications of your camshaft in order to calculate your DCR. With my setup I have been running a DCR of 8.5 and 91 octane gasoline. My SCR is 11.2:1. With 93 octane you could go a little higher. There are other things to consider such as a cold air intake and how hot your motor runs.

maroonls1z

yah i understand i need to know the closer degree of the intake valve but i dont have the cam card in front of me. was kind of hoping someone knew it. I have seen a thread about the DCR of the 110 LSA version and it gives a 9.1 DCR with the factory compression of 11.0:1 and 9.7 with 12.0:1. is 0.051 quench too high?

maroonls1z

Calculated the DCR at 9.15 with the 0.051 gasket, what's the highest people are running on pump gas?

maroonls1z

this seems high, any one want to help me confirm
269/2 = 134.5-(116+4 advance so 112?)=22.5+180=202.5...269-202.5=66.5 IVC

that give it a 8.7 on factory SCR of 11.0:1 AND 9.15 on mine of 11.58:1

KCS

iTrader: (20)

I would run it. If you're that worried, maybe you could retard the cam a couple degrees, delay that IVC and probably make a little better power up top with minimal loss in the low end.

maroonls1z

That was kind of what i was thinking, katech says if u retard the cam the 4* thats built in you trade about 5hp for 5tq, id then be running 0.041 quench which seems a more universally accepted number and my dynamic comes out at 9.0:1. I have 93 octane here and will probably run E85 on it when i can but i never know where i will end up and want to be able to run 91 octane if i have to