331 stroker with spark knock

[93stang burden]

OK i jsut put in a new 331 and I seem to have some spark knock at high rpm's. Pretty much anything over 4000 or so. Also it seems to want to idle a little rougher than i want . And if you clutch while driving sometimes it will die. I have an appointment to get it dyno tuned on the 27th of April put I wnat to put some miles on it before then. Here s a list of the mods.

331
AFR 185'S
70MM BBK TB
73MM C&L MASS AIR
PULLIES
BASSANI XPIPE WITH CATS/HEADERS
COBRA INTAKE
30LB INJECTORS
HOWARDS CAM 534/547 @.50 224/232
1.6 ROLLER ROCKERS
10.0/1 COMPRESSION


The builder says it should be about 400 at the flywheel does this sound about right???

 

[LarsD]

I wouldn't beat on it much until you get it tuned. A good tune will more then likely clear up most of your problems.

 

[Warbird19]

Are you running 92 octane? If not then youtun should be. What is your base timing? Your probably getting to much total timing to fast. Your tuner can fix that easy with a chip. For right now run 10-12 degrees base timing with the bung pulled. If its still pinging take more timing out. I dont think your pegging your mass air but its a possibility.

 

[93stang burden]

i run 93 octane and i have it set at 10-12 degree timing. what do you mean by pegging my mass air?

 

[Warbird19]

With a stroker motor thats making good power you could be pegging the maf. It says you have a 73mm maf which really isent that big. I mean pegging by the maf voltage is as high as it can go. Meaning you need a bigger maf. It works on a 5 volt reference, and voltage goes up the more air that passes by the sensor. If you get close to 5 volts then anything rpm above that the car cant adjust for the right fuel tables. Again your tuner can tap into the return wire on the maf and tell you if it to small or not. Whats your fuel pressure at vacume off? Do you know your total timing?

 

[korywiesner]

Get a quarterhorse!

How do you plan to tune the car? By what means are you going to tune the ECU? Unless you have a chip of some sort(Old technology) what is there really besides the base Idle to change? You may have an adjustable FPR or what have you.

If you want to actually see what your car is doing......get a quarterhorse. For less than 2 hours on the dyno and a chip you can have permanent datalogging capabilities. Every time you change or upgrade something you will need dyno time to fix your tune otherwise. The software for it is here. The site that the guys hang out at is eectuning.org. Then you can make changes yourself whenever you want. Plus it is seriously cool technology.

Really though it is a worthwhile investment.