I'm running a Holley 650 DP. Specs on motor in signature. When my car is warmed up, it puffs a very little bit of smoke out of the tail pipe and more when I rev it pretty high. It's idling a tad rich and can't get it to lean out either. Initial timing is at 22 degrees with 36 degrees in by 3,000 rpm. I run full manifold vacuum advance w/ the total timing at 45 degrees at idle with the vacuum advance. Any ideas on what this would be? The motor has 500 miles if that on it. Maybe this is normal with a camshaft this big? It's always done this and I've never really worried about it. Just thought I'd ask.

Thanks,

 

Any ideas guys? Is this somewhat normal with my cam / engine combination?

 

My first guess would be that it is running a little rich at WOT. However, I don't think that it would be just a "puff" of smoke. What rings are you running on the pistons? Perhaps the rings aren't fully seated yet. Are you getting much pressure in the crankcase?

 

Could be running to rich...

I have close to the same set up and had a 700 DP on it and it done that at idle If i reved it fast to like 4k rpm and let off it would stop(only done this at idle) Put a edelbrock on it and it stopped(I didnt leave it on) I put a new 800 dp on it yesterday and no smoke

 

Thanks for the reply. The motor only has maybe 400 miles on it. I don't really drive it at all. Do you think that's what's happening? The motor was built in 2007 and i don't have much run time on it at all. I have the carb set up pretty good in my opinion. The mixture screws are close to 2 turns out though. Thats the leanest it will idle...

 

It could be the problem. When it is just idling, do you notice and smoke pushing out of the breather on the valve covers? Are you running a PCV system? An O2 sensor would go a long way towards telling you if it is a carb issue. Once you start driving it more, you will have a better idea what the problem is. If it is burning oil...that should be noticeable on the plugs.

 

I run a pcv system and dont see any smoke coming from around that area. My plugs were black last time I changed them but that was from idling pretty rich.

 

A 215 is a lot of cylinder head for a 350. What is your compression? If the compression is less then 10.5:1, I would be shooting for an idle advance of 50-55*. I run that on my 10.8:1 350 with AFR heads no problem (using 93 octane).

If it were me, I would take the carb off, flip it over, and check the transfer slots to see how much they are exposed. They should be .020" max. It may turn out that one set is exposed a bunch and the other set not at all. You can adjust the secondary blades, but the screw is only visible from underneath the carb (unless somebody flipped it). If setting the T-slots, idle mixture screws and timing doesn't fix your rich idle...time to break out the drill bits!