DIY: How to adjust timing - 350 Chevy small-block


In this Hagerty DIY, Kyle Smith walks you through the process of adjusting timing on a Chevy small-block engine.

This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2017/10/25/adjust-timing-on-chevy-small-block


It is a lot easier to use a 9/16" distributor wrench made for loosening the distributor hold down then using a combination wrench. The distributor wrench allows you to loosen and tighten the hold down bolt from above the distributor. Ford & Chrysler products use a 1/2" headed bolt for the distributor hold down. There are also 1/2" distributor wrenches as well. I also recommend using chalk or white out to mark the timing mark on the harmonic balancer and on the scale to easily make the marks visible. Otherwise, you did a very good and through job of explaining how to set the timing on a distributor equipped engine.


excellent job with the timing demo. How about on on adjusting quick fuel 4 barrel carb? I could use a straight forward class


Agreed, excellent job on explaining the timing demo in laymens terms. Would also love to see how to set up 4 barrel carb. Having hard time getting a new rebuild dialed in. Major hesitation when lay into it for first few seconds in any gear.


Hey @oldsmobile15 -

Thanks for the comment, glad you like the video.

You are correct, there is dedicated wrenches for timing adjustments. Two reasons I didn’t use one- I don’t have one currently, and it isn’t necessary to complete the job. I have used one in the past and depending on the type, they can work really well or just okay. In building up my toolkit, I am still focused on multi-job tools and don’t have the budget just yet for a lot of the fun specialty tools.

Though I will admit, I hope my significant other gets me one for the holidays!


@steves70mach1 - Thanks for the comment! Initial setup for a new carburetor can be tricky. This is definitely something we will look into doing for a future video.


When you connected the lead to the #1 cylinder spark plug wire you didn’t indicate the direction of electrical flow. The timing light I use has an arrow on the lead to ensure you connect it properly. Does this not really matter or does your light not have this?


@jkphoto58 - The timing light I used was not marked in that way. With a dial back light (similar to what I used) I believe it would be important for the pickup to be oriented correctly.
If it was looking for signal in one direction and got it in another I doubt the dial back function would work properly.


Many engines will experience overheating if the ignition timing is retarded (not advanced enough). Often “unexplained” overheating can be traced to the timing. In older fashion mechanical-only advance distributors this problem would sometimes show up due to stiff old advance springs where base timing appeared OK, but on the road at higher (than idle) RPM the engine was running without enough advance. Timing caused overheating can happen to vacuum advance setups or mechanical-only advance distributors.


@morelists - That’s a good point and is something that is often overlooked in diagnosis of a misbehaving engine. Most get stuck in the thought that if the car is not missing, accelerates and idles correctly, then the problem cannot be timing. An experienced wrench remembers to check all the vital systems!