[arcticcatmatt]

Hi all,

I am about to give up here.. well I have given up and now I am online. If anyone is in Central NY ( I live between Ithaca and Binghamton) knows timing and would like to give me a hand I am willing to pay you some money.

Specs - 350 SBC with B&M 144 blower, brand new holley 700 cfm blower carb, mallory ignition.

I put the distributor back in just how it came out I thought but apparently that is not the case. I cannot keep the car running unless I feather the gas and it just doesn't sound like its running right.

I took it out and tried again.. still same exact problem. I contacted holley and asked them.. he said
“Blown motors like initial timing not total. Settings for your motor should be 14-16 initial and 28-34 total. Set idle around 1,000 rpm. Set timing while RPM’s are 2,500-2,800”

My tach doesn't work. Its an aftermarket electronic and it bounces all over the place.. useless

I have never timed a motor but watched videos online. The timing thing by my harmonic balancer goes up to 16 on top and down to 8. I have a timing light but not 100% sure how to use it as it has a dial on the end of it.

I am getting married in 3-4 weeks and I really need this car to be ready and reliable by then.

Can anybody help this rookie?

I loosened the dist. and tried to rotate it either direction and it ran worse, and it was a real pain to do alone.. trying to keep a car running, turning a dist.. and running a timing light, its almost impossible. I need a hand

[68NovaSS]

You sure your not one tower off on your distributor cap? With your timing light, set the dial on the rear at say 16 or 18, aim it at the timing tab and at idle, turn your dist either way until the mark on the balancer lines up with the tab pointer on the block. If you're running vac adv, disconnect and plug the manifold side.

I don't know what the tech was telling you, or if you didn't understand. You want all of your timing in, (not advancing any more), say 34 degrees, by about 2500 rpms. That could mean changing advance springs, an advance limiting stop in the dist. Set your initial at idle, say 750 or 800, if you need that much to keep it running.

I'm not sure what carb setup you have, or why you need to jazz it to keep it running. Can't you raise your idle set screw? And double check your wires and firing order. If it starts and runs, you should be able to pull in in line.

What ignition you using? What's your fuel pressure and float level?

[68NovaSS]

Was it running OK before the blower install? Did you do anything to the valves, new cam?

[F-BIRD'88]

Mark your balancer for 10th and 1/12th the circumference from TDC.

This is 36 deg BTDC and 30 deg BTDC respectively. The total timing at rpm will be 28 to 32 BTDC.

To get the right amount of initial timing at idle, combined with the right amount at high rpm for your blown motor requires modifying the distributor advance curve.
You want to shorten the advance travel to allow increased initial idle timing but limited max spark advance under boost/rpm.

You want a short 10deg advance curve. This will allow 18 to 22 at idle and
28 to 32 at max advance.
The stock out of the box distributor will not allow this, without specific modification.

To get this short advance curve requires modifyingthe distributor beyond what can be done with weight and springs and stop bushings.

Make sure TDC is actually TDC using a piston stop.
Any, all intake manifold /carb base/blower gasket leaks will cause poor running etc.

Exactly whcih mallory distributor do you have?

[arcticcatmatt]

It runs! Found a leak on the corner of the lower blower gasket using carb cleaner spray while it was running. I am going to use the information here in this thread you all were kind enough to reply with to check the timing next time i have a friend over help turn the distrubuter.

Pictures and maybe a video coming soon! posts are worthless without pics

[arcticcatmatt]

I am running a Mallory Unilite and MSD boost timing master. Thanks very much for the posts! I will be using that information this week

as promised! Drove it 60 miles with no problems today (besides my almost dead battery and 4:11 gears sucking 1/2 a tank of premium)




Video - http://www.youtube.com/watch?v=yAmOpZvzivg
Video - http://www.youtube.com/watch?v=YGLwOCukX8s
Idle video - http://www.youtube.com/watch?v=_KhVVC82TbM

[bubbahotep]

F Birds advice is always all you need.

Many tachs get screwed up with the multi spark systems. They do sell tachs specifically for these applications though

I do recommend a good digital timing light. Most, around $100, will display your real time rpm without jumping and they also have digital dial back features for timing if you dont have timing marks. I use the Equus 3568. It'll show the rpm on its screen and you just aim and shoot the rest.

The dials should have numbers which are how much advance you are "looking for". So if you set the dial to 16, and run your car at idle, ideally you should see the timing mark at zero (assuming you car idles at 16' timing).....meaning your actual timing is 16. If you were to turn the dial more as the car idles, lets say to 36, you'd see the timing mark move way off which means you are NOT at 36' timing at the moment. If you bring the car rpm to 3000, you might see the timing mark move back to zero on the balancer.....meaning you are now at 36' total timing at 3000 rpm. Hope that makes sense. The dials were useful when there was ONLY a zero mark on the balancer. If you have an 8 and 16' mark, you can use the dial to confirm that the marks are correct.

Timing lights, dials, and buttons, have no actual affect on your timing, they just show you what you're looking for.

Hope it makes sense

[Custom10]

I get ya bubba and you are spot on with how she works. If I could add a point here. Although the dial back is OK I have seen allot of posts that make me think that the OP (not in tis case) does not even know if what he is seeing is TDC or 0. Taking the time to verify that TDC is TDC by using the stop and making a tape cause the balancer does not go high enough is better than grabbing a dial back light, the dial back is almost too easy.

[F-BIRD'88]

The timing curve I outlined would be for a blown motor on 92 pump gas that does not use a Boost timing master to retard the timing as boost comes up.

That would want a different timing curve to integrate the BTM.

But all said and done the timing under boost still wants to be 28-32deg.

And blower motors as a rule like a healthy amount of base idle timing.

The BTM allows you to create a more optimum curve. (when they work right)