Ask Away with Jeff Smith: Recurving Distributors and Nitrous Codes

In this edition of Ask Away, Jeff Smith shows you how to create a distributor advance curve without a machine, and then tells you what those codes on your nitrous bottle really mean.

How to Set Up an Advance Curve without a Distributor Machine
J.D. asks:
"I’m in the process of tuning up the HEI distributor in my 350 small-block Chevy. The engine has a mild cam. My understanding is that to recurve my distributor it needs to be tested on a distributor machine. Where I live this isn’t an option. What other options do I have other than guesswork?"

All you need to make a custom advance curve is a timing light, an accurate tachometer, a pen and paper, and perhaps a friend to help record the information, says Jeff.

 it’s also important to be able to clearly read timing marks on the harmonic balancer. If the balancer doesn't have degree markings, Summit Racing sells adhesive timing tape for balancers of various diameters. You can also make your own with a length of masking tape and a Sharpie. Jeff explains how to do this and what the proper procedure to recurve a distributor is. 

What Nitrous Bottle Codes Mean and Why They Matter
M.A.'s question is short and sweet:
"What does the date code on my nitrous bottle mean?"

That stamp is the date the nitrous bottle was certified, Jeff explains. Every nitrous bottle must be re-certified every five years. Legally, a nitrous refilling station shouldn’t refill any out-of-date nitrous bottles.

This recertification process applies to most pressurized containers, even a simple CO2 bottle for a MIG welder. Jeff goes on to explain the process, and also warns you to check the date code on any nitrous bottle you buy to make sure it be legal to refill.