I have a 68 olds 442 with a 400.
I just went to an HEI distributor and need help to set the timing.
All I found on the balance was a mark which I suppose it TDC and another little tab on the side. How would I go about to set the proper timing on it?

 

You need a timing light. Yes there should be one slot on the balancerand the timing tab with marks should be bolted to the left lower side of water pump backing plate or timing chain cover. This tab will have marks on it for 0 5 10. You will hook timing light up to battery and #1 spark plug wire and with engine running turn the distributer and watch timing move. You should prob start with 8 degrees at about 900 RPM and see how it runs.

 

Also, remember that since the HEI has a different timing curve than the original distributor, you should set the timing for something like 32° with the advance all in (exact number will depend on your car's behavior), and then modify again based on how your car behaves at low revs.

Since the HEI has less centrifugal advance built in, you will probably get the best results with around 20° BTDC at idle. Because that 20° may not give you the best low-RPM timing, it may be to your advantage to use an aftermarket kit to re-curve your distributor.

- Eric

 

I do have the timing light and have hooked it up. The only problem I am having is that my vacuum advance is hitting my firewall when I turn it all the way back. Would there be a problem if I just take out the distributor and turn it a tooth or two for more clearance?

 

That's what you need to do.

- Eric

 

so set it at 8 degrees and this would be with the vacuum disconnected correct? Im about to go try it out and will get back with you guys to see how it runs.

 

Just want to let you know that I finally lined her up to about 8 degrees and shes never ran better. Thanks for the good info guys

 

Wait and see what happens when you bump it more! Do you have a set back timing light? Just disconnect the vacuum advance and set your total timing to 34-36deg BTDC at 3500 rpm. Then note where your idle timing winds up and take it for a ride. If it pings. back it down 2 deg at a time, until it stops. Thats what the engine will really like.

 

I dont know how to set it at 34 degrees total timing since my balancer doesnt have the timing tape ... All I have on my 400 is a TDC mark and the Tab that has 0,5, 10 degrees.

All I have is the simple timing light

 

My advice it to not try to kiss her until the second date.

 

This may be the time to upgrade your instruments. Check your local buy-n-sell stores for a nice cheap used one.

Oh, and Fuel Octane Rating has a huge influence on how much timing you can run. I bought a '67 442 engine in CA years ago, retarded timing to satisfy the smog inspectors and crappy fuel were NOT good for the 10:1 flat top piston motor. Overheated when stuck in traffic. spark knock if you advance the timing. I finally tried 100 octane LL airplane fuel. WOW, what a difference. Bumped the timing up, felt like adding 2 more cylinders, and all the overheating problems went away.

If your '68 G400 is stock, it's probably around 10:1 compression and should be running about 100 octane.

When I brought my E400 to MI, I ran 5g 110 racing fuel per tank of 93 pump gas. Worked great. But racing gas was "very expensive" back then- almost $4 a gallon !!!!

 

How about those little octane boosters sold at the auto parts store? Are those any good?

My engine is fairly stock... its a 400 bored .30 over with the new hei distributor and running a holley 4150 double pumper. I just changed the carb from an edelbrock 1411 that I wasnt to impressed with. Any advice on how to get more power? How much more power could I get by advancing the timing a couple more degrees? Is it worth getting the new timing light?

 

You can scribe new lines on your balancer. Looking at the balancer from the front of the car, measure clockwise and scribe a new mark. Take a piece of masking tape and mark a line at 1.73 inches for 30 degrees, and 1.97 inches for 35 degrees.

Or, turn your engine to the 10 degree mark, scribe a line at the 0 degree mark. Then turn your engine so the new mark is at 10, and scribe another line at the 0 degree mark. Third time will be 30 BTDC, etc...

Do as MDmechanic said. plug your vacuum line, and hold the engine at 3500 rpm. Check your timing against your new marks. Start at about 32 degrees and see how it works. If you advance it this much, limit your vacuum advance to 10 degrees. The stock vacuum advance can be as high as 20 degrees. You can get adjustable vacuum cans from Accel, Moroso, Crane, etc. Higher octane gas will allow higher timing. Too low of timing can cause overheating. I think if you set your initial at 8 degrees with HEI, it is way too low.

Also, what cam and pistons do you have? Do you know your deck height and compression ratio?