Thread: need help on timing '81 vette 350

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I've got an edlebock intake, holley 650 4 bar. settin' on top of stock 350/350 auto., changed distr. to a vacuum advanced and i can't seem to get the timing straight. I can get her to idle pretty good but it doesn't pick up when i stomp it. It studders bad and backfires in carb when stomped doin' 60. Can someone please walk me through startin' w/ initial timing and finishing w/ vacuum so I can double check myself? I'm about to pull my hair out. Thanks to all.

can anyone out there please lend a hand???

Where do you have the vacuum line attached? Above or below the butterflies? I believe your distributor requires ported vacuum (aboave the throttle plates) not manifold vacuum (below the plates.) Is my memory still working?

First, thanks a lot to everyone that puts in their thoughts. I'm new and really enjoy everyone's input no matter wheather it's big or small. I've always wanted to hear everyone who has an opinion, I find if I take them all into consideration I end up conquering my problems. This vette I've got, is my first big hotrod project and sha has turned into my BABY(a.k.a. major money drain). I know it's not nearly old enough for most of ya senior members out there but I'm only 25 and I love the big wavy hood and fenders. I've always wanted one between 56-82, so when I found her running good, with a new tranny, paint, and brake job for $4800(which is really cheap here 'round Dallas), I jumped. It WAS all stock and running ok, inside was shreads so I dumped a fortune into the interior. Now, I'm trying to get a few more miles and some more horses out of her before putting a new 350 in. Factory, she was barely pushin' 190 and that's just not right in a vette(can I get an AMEN???). Got the holley, intake, and dizzy for a hundred a piece. Rebuild the holley( runnin' 74s in the front and 83s in rear, not sure if that's good or not, any input would be appriciated, don't know what the power valves are), also don't know much 'bout the dizzy, it's suppose to be hi-per., has a red cap and roder. I've donaway with all the BS smog stuff, wiring, and hoses. I've tried to eliminate the computer from any control under the hood. Should have pictures pretty soon.

Now to the problem at hand, I'm in the dark 'bout how the vacuum all works, I never had any problems relating to this with my first truck, an '83 S-10, and I've bought and owned three new trucks since I started workin' at 18. I've come to understand that you turn the dizzy 'til ya get the highest vacuum pull at a 1000 rpms, with the advance unplugged and all vacuum leaks plugged, then plug the advance in which causes more rpms and ya have to idle down, what I don't get is if when you push it up to 3000 rpms is the vacuum suppose to go down and the dizzy retard a bit or what???. I've always thought the inner weights and vacuum-can was suppose to advance the dizzy as the rpms got higher, am I right or wrong or what???

Next, I'm really confused on what vacuum source to use. I've read everyone's opinion on intake vs ported and don't have a clue. If ported, what port do I use??? On my holley there's a small port on the lip that the air filter sets on(doesn't have much vacuum of course), there's two large ports at the base, in the center, just above the intake, one in front and rear. I've got the brake booster on the rear one, assuming that's correct??? There's two small ports on the pass. side, up front, at the base next to the large one. One of them is plugged to the choke. The only other port comes out of the slab that the front jets screw into on the pass. side, it doesn't seem to have any vacuum 'til the rpms get high. I would really appriciate any help anyone is willin' to throw in, Thanks again.


Oh yea, hey Henry Rifle, I'm sure fond of my Remington Rolling Block #1. She's chambered in .45-70 with a 2" thick, 26" long octo. barrell. She's sure got a lot of history to her, wish she could talk.

Start the car. With the engine running on idle, put your finger over the two vaccum hose bibbs. The one with zero (or almost zero) vacuum will be above the throttle plates (ported). The one that tries to put a hickey on your finger is manifold vacuum.

Or, you could use a vacuum gauge.

Take a look at these links:

http://lists.twistedpair.ca/pipermai...il/029574.html

http://www.chevyhiperformance.com/howto/97438/

- my great, great grandfather carried a Henry with the 7th Illinois Infantry in the WTBS, therefore, the handle.