73 nova timing

[Mxpx182lit]

Hi all,
I have a 1973 Nova 350 custom that came with a 2 barrel carb. I recently pulled the stock parts in favor of an edelbrock performer RPM intake manifold and 4 barrel carb. When we pulled out the distributer we lost the timing and dont know what the timing is supposed to be, right now its at 12, but is running poorly so we think it might be wrong. Thanks in advance,
Justin

[ridge_runner]

what size cam do you have?

[68chevelle]

well the obveouse question is did you get the distributor in corectly? meaning, the rotor pointing to the number 1 spark plug on the cap, while the engine is at TDC on the compression stroke.

[Mxpx182lit]

yes we have it in correctly, and im not sure what size the cam is, but i do know that it is stock.

[68chevelle]

are you sure that its the timing thats your problem. what size carb did you put on it? and is it bran new or did you get it from someone. if the distributor is in corectly it should run fine at 12. atleast not poorly. its seems more likely to be your carb. does it run fine if you bring up the RPM's a little or rev it and then will it run fine for a few seconds after you let the rpm's go back down. and description you can give might help.

[Mxpx182lit]

well its not really running poorly, its slower then it was with the 2 barrel. Its very slow off the line and doesnt pick up untill about 2500rpm. Also, sometimes there are deadspots in the acceleration and sometimes it stalls out before shifting into 2nd. It is a brand new edelbrock 650cfm 4 barrel performer carb. I bougt it from checker auto. All the jetting is correct and if the timing is not wrong i dunno what else could be. Please help, my race is the 31st.

[406Elcamino]

That intake is a little on the big side for a stock camshaft. That intake doesn't start making power until 1500 rpm. And the shifting into second make sure the downshift cable is adjusted correctly.

[68chevelle]

That intake is a little on the big side for a stock camshaft. That intake doesn't start making power until 1500 rpm. And the shifting into second make sure the downshift cable is adjusted correctly.

i agree that the intake is a little big. the regualar performer would have been a better choice. just because the carb is bran new does not mean that the jets are correct. did you change them at all? what carb is it? brand and size, (CFM's)? as for what 406elcomino said, im asuming you are refering to the detent cable. that doesnt control his upshifts whitch is what he is talking about when it starts to die. all it controls is the downshift from third when you get on it all the way. but even if it is not adjusted corectly it wont matter. also what trans do you have? if you dont know is it a 2 or 3 speed? im really starting to think its your carb. when you let me know what size it is and stuff i should be able to tell you what the problems are and why there are dead spots, (well the dead spots are probably the idle mixture screws being to lean).

[Mxpx182lit]

It is a Edelbrock Performer 650cfm #1405 4bbl. We changed the jets and rods for our altitude. The mail jet is 1427 (.098) and the metering rod is 1457 (073 x 052). The secondary jet is 2 stages lean (8%) with a (.089) jet. I am in colorado so it is a pretty high altitude. I have a three speed automatic.

[68chevelle]

well im showing the #1405 as 600CFM's instead of 650. but aside from that you leaned it way out. you should probably try putting in either the original main jets or the orginal primary metering rods. like i said before did you adjust the idle misture screws. if the dead spot in the peddle is like when you first hit it from a stop then its the idle mixture screws thats causing that, but if its when your already going then its probably that you have it set way lean. what is that alitiude that your at? do you know. cuz you do have it leaned way out. try swaping either the jets or the rods back and that will probably solve some if not all your problems.

[Mxpx182lit]

well the altitude im at is about 5300 feet. With the original jets and rods it ran way worse and fouled all 8 of the spark plugs. The mixture screws are prett lean also, because otherwise it fouls the plugs. And yes, when i hit it from a stop it makes a wierd pop sound and dies, do you think thats the idle mixture screws? Do you think it would be best to have a shop adjust it for me? Im 16 and have little to zero money right now, so id really like to be able to fix it myself.

[68chevelle]

ok well it sounds like you do need to adjust the idle mixture screws. try like 2 turns out. meaning turn them all the way in and the 2 turns out. i would see what that does. then check your exhaust and see if it smells rich or if you can see it. if so then lean out the carb more, not the idle mixture screws but the jets. sence you said it was worse before then you might just need to put smaller jets in. 2 jet sizes isnt much so you might want to try 2 mroe and see what that does. its probably going to just be a trian and error kinda thing. otherwise find someone around your place that is running a stock engine with that carb and see what jets and rods they are running.

[406Elcamino]

On the edelbrock and carter carbs they always say to start with the metering rods first when making metering changes. Sounds like it is too lean. As for the idle mixture adjustment, do you have a vacuum gauge? Hook it up so it reads manifold vacuum and slowly turn the screws one at a time until you reach the maximum reading you can. Will start to go down again when you are too rich. Another quick test is to give it a tiny spray with carb clean down each carb barrel. Will speed up if the mix is lean and stumble if it is rich.

[nova73apred]

i also have a 1973 nova custom, i recently did the same upgrades, but not exactly. i did a 500cfm 4 barrel carb(edelbrock performer series) with a performer series intake manifold.it istn running correctly!it backfires through the carburetor, and like the other guy said it isnt quick off the line. i am fixing the backfiring, but not sure what it is. but i would liek to know where i should lead to with improving horsepower and quickness.what kindof upgrades should i do?im only 16 and am learning alot about cars now.thank you for anyone that can help me with this.

[PMDMAN1978]

I hate to be the barer of bad news but the reason it runs like molasses in January is because you have to small a cam for the intake and carb you are running. If I may I suggest that you try a cam from edelbrocks preformer line that should solve all you problems provided you don't pick to big a cam. Good luck.