I have a 72 nova with a 496bbc 990 rectangle port heads, cam is 589,256in 612,265ex 110lobe sep. I know this isn't a good cam but I'm just getting this together and improving as I go. Turbo is a 101mm,godzila bov, newgen waste gate, csu 850 dual brpv, e85 jets are 88 93(the carb was a gas carb, bought metering blocks from csu for e85 and jetted it rich cause i didn't have a wide band hooked up yet....hmmm that reminds me I still need to get some vent extentions)

Ok I'm set at 5psi when I get in to it, it seems ok till it gets into higher rpm(any thing over 5500) then it just misses here and there(not just one hole) so I changed my plugs(ngk 9's) set the gap to .015 from the the previous .035.........ok so I figured that i had the problem beat. so I turned up the boost to 11psi(stupid) and it was still missing so I put it back down to 5psi and tried it on the trans brake. It gets to about 5500rpm and starts missing.

would my crappy ss blaster coil be to blame? or could it be a fuel issue? maybe timing issue?timing is 24*(i have a btm box, but no time yet to hook it up so the timing is set to 24 total.

If you need more info please tell me. I could take a vid

 

Can you make a video? My BBC is doing the exact same thing right now and I'm getting ready to change out the valve springs.

 

What valve springs do you have on it?

 

I can't remember which ones but the are 130 pounds on the seat. Do you think that at that low of boost it could be a issue?


Actually its not the springs.. Bbc float the intakes first,it would be popping badly in the intake if this was the case.

 

Is that a roller or flat tappet cam? How old are the wires? What do the plugs look like?

 

Put the WB in and take a look????
Plugs at .015 gap???

 

Check for spark jumping out of your wires. Hard to see under load unless you have a Dyno though

 

Check your grounds! I had a similar problem and had to run a ground wire (4 gauge) from the battery to the heads. I spent about $3,000 changing things with no luck. Grounding the heads solved the problem. Its a cheap fix that's worth a try before you start replacing things.

 

Flat tappet, plugs are new(probably dark by now but missed right after replacement).

015 plug gap yes. I will get the wideband in there asap.(would it miss if it was too rich on e85? its not shooting black).

I could get another set of wires. They were new last year.

I have the battery in the trunk with the ground attached to the cage pad, I have solid motor mounts. But putting more grounds can't hurt. I'll do that.


I was going to buy a msd hvc coil hoping that it would help out. the blaster ss that i'm running is a cheaper coil. Has anyone made any power out of one of these?

 

Are you plugs too cold?