Thread: Locked out timing? Picture look right?

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Does this look right? What needs done to the vaccum advance besides leaving it unplugged?


http://inlinethumb48.webshots.com/44...600x600Q85.jpg

Nothing..just leave it unplugged

what's the application? Just wondering why you're not using it. On a race car it won't matter but street driven vehicles benfit from the vaccum advance. Part throttle driveability is way better with a properly adjusted vaccum advance. Fuel economy is better and I've found most engines run cooler with the added timing at part throttle.......hook it to ported vaccum and it will idle like it's not hooked up and it will have no affect on full throttle performance. I just made a believer out of some folks last week on a '67 mustang with a 428cj. Car has a msd distributor and the advance was plugged off. I hooked it up and driveability was night and day different. Felt like it was in a bind at cruise speed and built a lot of heat without it. You want the highest timing possible without detonation at cruise speed and an adjustable unit helps you get it just right. If it's a track car just unplug it.

The main use is in a pulling truck.

Originally Posted by GMC400

The main use is in a pulling truck.

Please be specific. "Pulling" as in pulling a sled in a stadium or "pulling" as in towing a heavy load on the highway???

Start at the beginning and outline EXACTLY how the motor would be used. You wouldn't go to the doctor and tell him you have a pain without being specific, so help us out here.

Pulling a transfer sled. The engine is 11:1 comp. 4" stroke, 4.155 bore. (434sbc) solid flat tapped cam: 264,264 duration 0.50" 0.548,0.548 lift isky cam. Dart iron eagle platinum heads: 230cc runners, runners smoothed, 2.08, 1.60 valve. Victor jr intake with built in 1" spacer. MSD 8.5 wires. Hei distributor. Edelbrock 750 cfm tuned to engine. Truck pulls in a street "legal" class. TH350 trans rebuilt for engine by local race shop. 203 transfer case w/2:1 low range. 1410 series rear u-joints. 3.5" diameter drive shaft w/0.083 wall thickness. 14 bolt rear end w/ 4.56:1 gear ratio 11.5" ring gear w/ posi. Redone front drive shaft w/ Dana 44 front axle w/4.56:1 gear ratio. It's also running 33x12.5x16 super swamper boggers or 33x12.5x16 bfgoodrich at's. 26" hitch height. Truck weighs 5200lbs before weight. Weight class is 6200lbs. Usually placed in the front of the bed or in a weiht box hanging off the front. Track is 300ft with a floating finish line, usually made of clay. Sorry if it doesn't make much sense, this was typed out on a phone.
Joe

you definately don't need vaccum advance for that....leaving it unplugged should be fine, but I'd try to lock it somehow if it were me, though it probably doesn't matter.

Geez Joe, too much information!!!

Originally Posted by techinspector1

Geez Joe, too much information!!!

Haha. I've been meaning to write the specs down for a while now anyway.

After the original question I had a link to a picture. The distributor on the left has a plate I made to lock it out. I was curious if that plate would be all I would need or not. I had assumed that with that set-up it wouldn't hurt to leave the vaccum advance off. I just wanted to make sure the plate had the right concept behind it.

On a side note, any estimates on flywheel and rwhp givin the specs. Also it has a 3800 TCI stall converter. Once again if it looks weird typing off the phone. Thanks again.

Joe

you can make up a tab to keep it from moving or pin the plate the a 10 32 long screw and some nut s is how we used to do it