I have a 290hp 350 crate engine and the timing is supposed to be set at 34 degrees BTDC total timing. How do I set total timing??

 

There's a sticky at the top of the forum.

http://forums.corvetteforum.com/show....php?t=1430339

 

A dial-back timing light is well worth the money.

 

What will a dial back light give me? I've got an old simple one.

 

With a dial-back light, you don't have to re-mark your harmomic balancer or use a timing tape.

You can drop me an e-mail request for my timing paper. It has instructions for setting total timing with a dial-back light or with a standard timing light like yours:
V8FastCars@msn.com
Lars

 

Most balancers don't have enough markings that will allow you to see the top end of the timing curve. An adjustable light has a **** (and timing scale) that you keeping moving (at some constant RPM) until the light's strobe is showing on the 0* mark on the balancer. You can then read the true engine RPM by looking at the light's timing scale. For example, if the balancer's scale only goes to 30* then there is no way with a simple light to get a reading once the engine's timing increasing beyond 30*. Therefore the use of a simple timing light limits you to only setting timing at close to idle speeds and you can't determine your true advance curve and max. advance.

 

Can anyone tell me why in like a Chilton it has base timing listed for all sorts of engines and The 290hp crate engine I have says 34 degree total timing. Why not a base like all the other engines I've seen??

 

I'll venture a guess why:
Chilton's and other similar manuals are probably assuming that the distributor is stock and not modified and has the correct factory curve still in it. If that is the case than by setting base or initial timing than the total riming will also be correct to factory settings.

Realistically, cars with distributors have some years on them now and greater chance than not someone has been inside the distributor before, changing things, modifiying it, etc and more chance than not the factory set curve is no longer there and it's been changed to some degree or another. Even if no one has been insode the distributor the curve may be different because of items wearing out: a good example is the stop bushing - they tend to get broken and fall off and that will very much change the amount of mechanical advance you get therefore changing the timing curve.
If you set the timing now based only on initail or base timing your total timing may be way off from optimum.

By setting for total timing you are sure you are in a more optimum timing setting, not only for performance, but also for safety so that your timing setting is not too high causing you to run into detonation issues.

If you are new at setting timing, read the sticky at the top that someone already included the link for and also read the tech papers referenced in that thread. It will take you from start to finish and when you are done you will know your distributor is set up correctly.

 

Chilton's gives you specs to set up to the manufacturer's specs. The manufacturers are not concerned with performance - they are concerned with emissions. If you want to tune for emissions due to your concern for the planet, set it up with initial timing as shown in the published specs. If you want to have fun with your car and set it up for performance, you do a performance tune on it, and that means setting up total timing. Initial timing means nothing: the engine does not run at initial timing at elevated rpm.
Total timing does not keep your local Greenpeace activitsts happy.

 

If I wanted to keep THEM happy, I'd slap catalytic converters on my '71 and only drive '55'.
Thanks again, LARS and everyone else! I gotta get a dial light....

 

I have a question. I plug the vac hose from the carb that runs to the dist. Now if I check base timing lets say it's 12 degrees and then I hook the vac line back up and check it again it should jump up to 12 degrees plus whatever my vac adv adds. correct? I am just trying to understand all of this.

 

Thats a pretty long read. But it will be well worth it , you"ll understand your dist. and all about timeing, you"ll also know more about timeing than 95% of most people including most mechanics. It can be a little confusing at times but there"s some extremly paitent guys that are kinda smart on this forum that will bend over backwards to help you understand. There"s only one catch, when you start asking questions it gets reel obsious if you"ve read it or not lol!
I"m no timing expert but i did read everything i could about 10 times and i still had a couple questions. I"ll try and answer your first question because others want you to read the artical before they start giving answers.
unhook that vacume line and plug it, now find out how many rpm"s it takes before the timing mark quits moving, shining your timing light gently rev your engine till the mark quits moving thats called total advance come back and tell us how many rpm"s and with your new dial back timing light turn the dial on the light till the timing mark lines up with the pointer. Your answers will be it"s all in by _____ rpm"s and it reads _____ degrees on the dial on the timing light.

 

You can also go to this page scroll down you will see the papers on timing, note the authors names he"s a forum member and he"s pretty sharp on this stuff !!!!!!!!

http://lbfun.com/Corvette/Tech/vettetech.html

 

Thanks for the info. I did read the article on it. i just want to make sure I am doing it right. The specs for my engine say 34 dregees BTDC. I hear 36 degrees is the recomendation for most engines. Which one do I go with? Anyway I just set the dial back to 34 and then run the engine up to the speed where the timing mark quits moving. If it stops moving at the zero mark then the engine is at 34 degrees. right? It should fall in the 2500 to 2800 rpm range correct?

 

34 is your total timing not your idle timing.
If you are hooking up a vacuum line and the timing goes up, then thats not the right vacuum port.
You want a port that doesn't pull vacuum at idle but pull when you give it gas.
You are running at full advance all the time,that is useless.

I would set your idle timing to the top of the timing tab or 12 for now and don't hook up a vacuum line until you get a dial back light.
Timing is so simple but directions make it very un-understandable!!!!!!

 

If it stops moving at the zero mark then the engine is at 34 degrees. right?
That"s right
It should fall in the 2500 to 2800 rpm range correct?
That"s also correct

Try setting it at 36 and see if your hesitation goes away, You"ll also need to listen for spark knock, (detonation) if you hear spark knock you"ll have to go back to 34, (or) get gas with more octaine ! Do not let your new engine spark knock

 

Do you know what Mr. gasket distributor spring kit # I will need? It is set at 8 degrees BTDC initial timing. I drove the car last night and it did ping a little. I am picking up my dial back tonight. whats a good baseline to set the initial timing to to get to total timing. 12 BTDC ??

 

Go for the 928 kit. Lars will tell you, its meant for older systems but the kit for the newer dizzys has alot of extra crap that isnt required. The springs should be all you need.

http://store.summitracing.com/partde...G&autoview=sku

 

928 is meant for points type dist. It will still work with Hei??