new intake and carb...issues

[my66coupe]

Ok a buddy of mine recently aquired a 67 coupe 289 C-code. Decent looking, rebuilt engine and tranny. After finding the c code was healthy, we decided to add a performer intake and 600cfm carb this weekend. Well today we took it for a ride and the performance is noticeably worse. The timing was set at 12 degrees. the carb mixture screws were adjusted. We also did the petronix ignitor 2 and the flamethrower coil (.6ohms), new wires. cap and rotor. The symptoms are....it stalls when navigating slowly in reverse. On right or Left turns it stalls. It wont start unless you have the pedal mashed. Im starting to think the carb is a factory mess up. Its a manual choke which is open and not a variable. Everything else on the car is stock. The exhaust manifolds are the emission type that run a tube into the stock carb, we removed the tubes, and now he has 2 small holes in his manifold (passenger side) soo it leaks. We didnt hook up the C-4s vacumm to the carb, only a vacumm port off the intake...does that matter? I got a vacumm guage on the carb and it read around 15-20 lbs depending on the degree. with more advance came more vacumm. It seems if I changed the timing from 6 degrees to 12, it wouldnt change anything. I did remove the vac advance when doing the timing. Well thats all the description i can give. Thanks guys

Mike

Ps. Are the heads different on the emission equipped cars? This thing has small spark plug threads, (uses the 5/8 type plug) and just doesnt look right. I bet these heads are a major restrictor on the performance level...correct?

 

[D.Hearne]

Did you check the float level? Sounds like it could be way too low judging from the way it acts, any movement with a too low fuel level can uncover the jets. What brand carb is it? The vacuum source you choose for the C-4 is perfect. Also the heads are not the originals, the small plug heads appeared in the late 70's. If they're the D8OE's then , yes they can and will provide less performance than the heads that his car came with. They would have larger combustion chambers which lower the comp ratio.

 

[my66coupe]

its an edelbrock. I am familiar with a adjusting floats on a holley, but not with the edelbrock. I have the owners manual which probably describes it, but just to make sure....where are the floats located on the edelbrock? internally? On the holley 4160 the floats are right up front and in the rear (easy acess to the needle) but this carb looks nothing like the holley. Ya this car is definetetly a dog, A c-code with bigger combustion chambers.....talk about a low compression motor. so much for the edelbrock way of bolting on and running/setting and forgetting. .

Mike

 

[D.Hearne]

Can't help you on that E'brock carb, I've never fooled with one either.

 

[302 coupe]

you have to remove the top part of the carb, you'll plainly see the floats, very simple.

Also, if you bought the carb new, you need to refer to the instructions before you do anything else. If you bought it used, you have no reason to fault Edelbrocks "bolt on and go" reputation.

 

[my66coupe]

well went to adjust the floats, and found that one of the metering rods was bent, and the floats were out of wack. Fixed everything up, and it did improve slightly. how much timing should i have on this thing to run it properly?


Mike

ps It's a brand new carb.

 

[D.Hearne]

You were on the right track with 12 degrees initial. If it pings with that, either use better gas, or retard the timing.

 

[krash kendall]

You were on the right track with 12 degrees initial. If it pings with that, either use better gas, or retard the timing.

I agree completely. That is how I set mine up. I have a new edel. perf. man and edel. 600cfm elec. choke.

BTW D.Hearne, Ive been out of town all weekend and want'ed to apologize about that whole key/ignition thing. I thought they used the same dashboard ignition untill they switched to the later type.

P.S. I've been married for 7 years and have a 2 year old son, so I'm not some young punk! All the best to you and yours!

 

[D.Hearne]

BTW D.Hearne, Ive been out of town all weekend and want'ed to apologize about that whole key/ignition thing. I thought they used the same dashboard ignition untill they switched to the later type.

P.S. I've been married for 7 years and have a 2 year old son, so I'm not some young punk! All the best to you and yours!

Not a problem What key-ignition thing ?

 

[D.Hearne]

P.S. I've been married for 7 years and have a 2 year old son, so I'm not some young punk! All the best to you and yours!

I've been married now for 26 1/2 years and also have a kid, but mine's now 19 You ain't got to enjoy the best parts yet, either in the kid or your wife.

 

[krash kendall]

Time to get back to talking tech now!