Thread: Distributor Adjustments

Tweet

I have a 1970 nova with a 1983 305 v8 (converted back to points style ign) and i am about to install a new intake manifold.

Right now i have the timing set to the stock degree, but I have been told by 3 people that if I cap off the vacuum advance on the distributor, and then set the timing to 32 degrees , that it'll yeild the most power from the engine.

I just wanted to get some opinions on this and if anyone has had experience with this.

Good idea or bad idea?

Perks/Downsides?

Thanks
Dallas

Dallas, they are referring to the total timing with the vacuum and centrifugal advance all cranked in. You would check your total advance at about 2500 RPM. To do this you will either need a timing tape on your balancer, or a timining light with the dial advance on the back end of the light. Some of the chebbie guys should be along with advice on your initial timing, I'm sure.

in my opinion it is a bad idea because when u try to fire the engine it will have 32 deg. advance from the get. it may start ok when cold but as soon as it is at operating temp you will need a switch in place to shut off power to the positive side of coil so you can get the engine to spin then flip the switch on to fire it up. locking a distibutor on a street car is a bad idea.

wenpen

one more thing, why points HEI the only way to go.

wenpen

I went with points to keep the originality look under the hood. I have an HEI setup, but i want to get a new cap, rotor, coil pack, etc etc before i put it on. On the caprice it would start dying out about 3500rpm, the nova with points pulls all the way (without sputtering/misfiring) to about 5300rpm. I usually shift at about 4600rpm.

Anyone know the powerband on a stock 83 305? I know it's 150hp/240ftlbs, but where does it start and end? it feels to me as if it doesn't really get moving until about 2200rpm and then it starts dying off at 4500rpm.

We have the timing light with the adjust/advance on the light.
I can't remember what we have it set at right now, anyone know off the top of their heads the stock timing it should be at. I was told 12degrees and someone else said 4. I can't remember what it's at now, but it runs well.

So wenpen, if i did the overall timing to 32 degrees, id stil have the problem you stated?

Theres a guy who lives down the road from me..i don't know him but he's got an 8 second 79 camaro dragcar. It's beautiful! all tubbed, caged, blown 540 bbc, 4spd trans manual. He idles through the neighborhood in it at like 30mph without even touchin the gas lol. I might stop by, he's supposed to be a chevy guru, the guy that helps me with my car (ford guy) went to high school with him and said he always had the fastest cars, and they were all chevys. lol..Just hope i don't freak him out when i go knocking on his door. heh

Dallas

Oh one more thing, I'm looking to get my vacuum advance set and the distributor dialed-in if this 32 degree thing flops (lookin that way!) anyone know any good shops in florida (preferrably orlando area) that could set it up right, and also tune a qjet carb?

Dallas

Take off the vacuum advance line and plug it. Set initial timing to 8-12 degrees advanced at idle 600-800 r.p.m.'s . This is a good place to start . Total timing should be in at 25-2800 r.p.m.'s this should be around 28-32 degrees advanced . Every engine is different . these numbers should get you in the ballpark though.Use a quality light , one with an advance knob and get some timing tape for your size balancer.

if you want to keep the original distributor look but want to upgrade... go with a pertronix unit in there... they're inexpensive, lifetime warranty, and they really do work well, the ignitor 2 is rated to 10,000 RPMs without any spark lag, and i'm sure you wont be wanting to push it that high anyways

Well, i've seen a few books saying the timing for a 1983 305 should be 6degrees. at 500rpm. I'm going to try your suggestion first 327 Jet. Hopefully it'll work well! I'm getting really irritated with this thing. All of a sudden after swapping the intake manifold (performer EPS) it is just all screwed up and runs smooth for 15 seconds, then backfires through the carb. UGH!

I wish i knew someone who was good with chevy engines/carbs!