it came to my attention that my cr is higher than i anticipated. I wanted to get an idea of what octane and timing advance i should be running. here it is.

406 ci

srp forged pistons
11.6:1 compression
edelbrock performer rpm heads (64cc)
air gap intake
demon 750
full msd ignition
cold ngk plugs
crane 302 h06 cam

my hope is that this long duration cam will bleed off some pressure, the -5cc pistons and the shape of the combustion chambers will fight off detonation and let me run 93; do I have a chance in hell? if you can relate some similar combinations that would be great. thanks in advance

-Louis

 

How did you calculate your comp ratio? Aluminum heads like a little more compression than iron anyway so you might be ok... what is the dynamic ratio w/ that cam?

 

how do you figure 11:1 with a dished piston and a 64cc head?

 

That's way too high for a street car. You'll be mixing your own race gas.

Look at trading in the heads, or the pistons, your choice.

 

this is my rotating assembly

http://www.speedunleashed.com/Eagle_...A-p-18722.html

i dont know how to calculate dynamic compression. I dont really mind mixing in a gallon of 100 with a tank of 93 if thats gonna do it. the car will most likely end up being a weekend warrior anyways.

RsPower, do you have any experience running an 11.6 motor on 93?

thanks

 

5 cc is valve reliefs only. -5 cc is a domed piston.
----------
One word: "E85".

http://www.e85refueling.com/location...664adc6b6f720d

 

will my demon and factory fuel lines be ok on e85?

 

No worse off than my '57 for the fuel lines.

Demon - not sure what BG has done for E85, if anything. Mods are needed to the jetting, idle & PV restrictors, and emulsion bleeds (not the air bleeds).

 

Well, now I do know - http://www.barrygrant.com/news/artic...ghty%20E85.pdf

 

are there stations that actually sell E85 around in a lot of states now? I've been looking into it but have no idea where i'd be able to get any... does anyone know of any stations in NJ that actually have E85?

 

According to the site above, NJ is a "blue state" - meaning no known E85 stations in that state.

How's that for irony? A traditional Democrat state with no E85 available. . .

 

Install the cam "straight up" on 106 intake C/L.
It normally goes in slightly advanced (102 intake C/L)
retarding the cam slightly from cam card specs will tame the running cylinder pressure. (later intake valve closing)

"Lock out" the distributor mechanical advance and set the timing at 29 to 32deg at idle. Go real easy on the amount of vacuum advance (8 to 10deg)
use slightly cooler spark plugs Champion RC9YC or RC10YC
keep the jetting a little rich.

the cr will only be 11.6:1 if the piston comes right up level with the block deck@TDC. "0 deck" clearance

If the block has not been "decked' the piston will likely be .025" down the bore @TDC 10.93:1 cr with 64cc heads.

 

SO, I paid a visit to my engine builder today... and it turns out that he gave me the wrong part number! who would have thought, its actually a 10.4 compression. Sorry for all this but I didnt learn from this
thanks for everyones input