1970z28camaro
05-31-2007, 12:04:09 PM
I want to know how can I have the most spark using a Mallory Hyfire box.
My distributor advance is 12 degrees with total timing of 34 degrees. I have 24mm vacuum and I am changing my Holley Avenger 770 jets two sizes down.
My plugs are still black. I am running 110 octane gas with a 11:1 compression.
Should I decrease the octane or can I adust my spark? I don't want to go too lean though.
Marv D
05-31-2007, 12:08:08 PM
That's only the tip of the iceburg,,, What plug are you running?
Marv D
05-31-2007, 12:39:30 PM
PM sent, get rid of those Bosch platinum plugs and I bet everything about this motor gets better.
hhott71
05-31-2007, 01:23:59 PM
11:1 works fine on 93 octane
Mwilson
05-31-2007, 01:28:56 PM
sounds like there is plenty of tuning needed what cam are you running with the 11:1 compression? 93 octane should run good.
1970z28camaro
05-31-2007, 01:43:03 PM
Competition hydraulic with roller rockers. 0.488 lift and 0.494 exhaust.
It is one of the high energy kits from COMP CAMS. I would have to do a little research to see what duration it is. I changed the cam profile slightly from the stock solid lifter 0.458/0.464 profile from stock.
Rat Race
05-31-2007, 11:25:17 PM
Dont want to jack thread, but im using splitfires. How are they Marv?
Doug Jaynes
06-01-2007, 08:24:35 AM
you can not accross the board say 93 octane is ok with an 11 to 1 motor , but many engines will be ok with it. mine is 11.3 and it like 94 sunoco. I use 110 when Im spraying for large bugs in the cylinders.....
110 is probably way more octane than you need for a na 11 to 1 motor though I doubt that has anything to do with your plug color
you dont mention what heads you run but you can maybe run a couple more degrees of timing if they are regular old school heads and your probably still way too rich. a wide band 02 meter would be handy right now for you
DJ
Marv D
06-01-2007, 02:05:12 PM
Dont want to jack thread, but im using splitfires. How are they Marv?
please tell me your kidding......
let me just quote something from a long long time ago....
From HP Books "how to hotrod small block Chevys" 1976 edition
In desperation, others have installed "guaranteed, life time, more horsepower, mileage and engine life" trick plugs. Don't bother. No one winning any races uses them - so why should you? Most of these plugs, easily identiied by the full page adds used to advertise them, appeal to the "something-for-nothing" owner who thinks that screwing in new plugs will give instant and enormous improvements in HP and mileage. We all know that this is impossible and so do you. But, Barnum was right, there IS a SUCKER born every minute. remember, 'I' didn't say that and don't take offense.
The best plugs on the market today ((IMO) for the street is:
1. ACDelco,
2. Autolite's or
3. NGK
For all the trick multiple ground, platinium, irrodium, unobtanium silly @$$ plugs,, please refer to what we knew way back in 1976. It's all just hype to empty your wallet.
The best race plug I've found is Champion race plugs or NGK, they both seem to hold up equally well. I've never used Autolites race plug so have no opinion on them.
