timing Vs fuel

hello all

if i bump up ther timing a bit do i need to ajust the fuel ie add more fuel , we a re looking at going from 30deg of timing to 32 deg of timing in a bloeing hemi making 30 pounds in a funnycar .
cheers

 

Yes, generally increasing timing will make more pressure and heat in the chamber these changes will cause the peak cylinder pressure to occur earlier ( degrees atdc ) by adding more fuel you will allow the peak cylinder pressure to occur at the same time ( degrees adtc ) and you will achieve more cylinder pressure for a longer period of crankshaft rotation.

Just my 2 cents,

Richard Gavle

 

as far as more or less fuel ,no 2deg.I would leave my fuel alone..think about a 6 shooter!!!!!! we change our timing 3 to 4 times during a pass..hope this might help you Dave
www.myspace.com/daveloweswr

 

my thinking on this is what do the plugs look like now and what kind of mag do you have i agree with what you guys are saying but if you are running 30* and the plugs are frosting all the way around (burning the catium off) bumping it to 32* i would be inclined to fatten it up just a little if the plugs are only burning 1/2 to 3/4 then no i would not add more fuel but bumping it up will burn more fuel and if its a 44amp mag be very careful its not as forgiving as the mag IV just my toughts

 

good call on the plug issue Jim....Dave
www.myspace.com/daveloweswr

 

hi guys , it is only just starting to burn the catium of the plugs ,not even half way round , the car only has a super mag 4 at 5.2 amps , we have a ken lowe fuel system and have got to the end of the settings he gave us as far a leaning it out go's . this is why we think we need to start to bump up the timming . the bearings look fine .

 

do you run a high speed, and are you running 1/8 are 1/4 mile on the mag IV i run 34*to 36* with my 44amp msd 30* to 32*

one other ouestion is it going down the track with out any problems like tire shake

there are several ways to hop the motor up just watch the plugs it will tell you what it likes a happy motor is a good motor a pissed off motor sounds good but the eat parts no fun

 

hi yes we have a high speed and we run the 1/4 mile , no tire shake at all , we did have the car wanting to bounce a bit ,but have taken the clutch weight down and that has fixed that problem as per a post that you all helped me with a little bit ago , we still need to take a bit more out of the clutch , its an 11" crower 3 disk pedal 6 stand with 48 grams at the moment . but i want to bring the motor up a bit more . we have only run a 7.3 at 190mph so far.still only just starting with this car .the high speed comes in at 110 psi and has a 90 pill in it .
cheers

 

i would like to know a little more about your motor size blower size cubic inch and over drive of the blower

 

hi jim

it is a 498 inch hemi iron block with dart96 fuel heads , 11.5 comp 1471 standard helix blower running 41% over making 30 pounds .we run a 990 pump making 15.4 gal with a pump sizer set at 28 pounds with a 85 pill ,high speed with a 90 pill at 110 pounds and the main pill at 100 with 6 pound popet , port popet at 12 pounds , i think the hat jets are around 52 and the ports around 32 at the front going to 36 at the back , 8 nozzels in the hat .

cheers

 

A couple years ago I had a motor in which I couldn't seem to put any heat on the plugs.
I went round and round trying to figure out why. It ran fine, seemed to make good power, I was competitive on the track (this one didn't go to the dyno), but not heat on the plugs.
I ran the fuel system on the flowbench and compared it to like motors I had, it was actually leaner
I re cc'd things thinking I accidently had less compression, rechecked ignition timing marks thinking I had less timing in it, changed and had mag checked and changed the cam(same grind) but I found no mistakes.
At that point the only thing I could think that was different, was how the coil was mounted. I than put an extra ground wire from the negative post of the coil straight to the cylinder head,,, and BINGO, lots of heat.
The coil was grounded and the motors are solid mounted, but... evidently not enough of a connection.

 

my advice would be when you bump the timing up put a new set of plugs in make an 1/8 mile pass if the plugs look good ( like starting to burn more catium off say half are less ) then make a 1/4 mile pass always read your plugs and only make one change at a time any tuning change put a new set of plugs in understand what the plugs are telling you you should be fine good luck

as long as the track is good more power is good

shitty track more power is bad

 

thanks guys , we race this weekend , i will let you know how it went .

cheers

 

we went up to 33 deg in the mag ,the car picked up well ,went 7.05 and i lifted well before the finish , very happy with the improvment and the plugs are starting to get a bit of colour , but it still looks like there is a lot more in it yet
cheers to all the people that gave there advice .