I've had this car for over a year now it's rebuilt ground up. It's been about three years since completion. I bought it from a collector. It's in great shape over all and runs pretty good. I've been going over the tuning and found a few issues replaced Plug wires and plugs (it had two steps cooler heat range) adjusted air fuel on center carb with vac. I'm getting there. The carbs are in good shape no leaks fuel or vacuum. the problem that remains is when at WOT it pings a bit and needs the timing zeroed in correctly I believe. I have found no tune specs for this rebuilt 66 400 tri power. I have Chilton manuals for this era cars but the Olds 400 tune specs are only available for 4bbl at 71/2 btdc. Now if i look up specs for it's tri power GM brother 64-66 389 GTO ignition timing to 6 btdc. Ok close enough but I'm a few degrees more. Hate to just hunt around with the distributor so I ask has anybody seen official tune specs for the 66 Olds L69 tri power? Also it has a pertronix distributor and coil no points.

 

What fuel Octane rating do you use? With your vac advance disconnected and plugged, what is your timing reading at the RPM it stops advancing and at what RPM is that?

 

Read your plugs you may find that the primary carb is jetted too lean, I have the the same set up and center carb has 0.67 jets

 

Sounds like gas quality to me. Keep in mind your car when new required 102 octane leaded... No matter how you play with ratings variables. You are not getting anywhere close to that at the average gas station.

93 octane with a booster may help.

 

The Tri-Carb engine uses the same tune specs as the 4-barrel. However, in 1966, the 4-4-2 came with a gas cap that said premium fuel only. Today, as noted above, adjust timing so it doesn't ping. Also, there is/was a rubber stop bushing under the distributor weights to limit total timing, It could have degraded and fallen off by now.

 

thanks all for the info and ideas. All have merit and I plan to check all of it at least until the problem is squared away. Will start with fuel quality, using 91oct now. The timing is set right at idle 7btdc need chk max timing. Take a look at the advance weights and hope that the jets work out as is. Again appreciate it.

 

Go to an airport and try 100 low lead aviation fuel.😀

 

I hear ya! and I think it's on the right track but don't wanna be hanging around the flight line trying to fuel up the 44duece. I did just order a 10 pack of Lucas fuel booster I'll give that a chance along with some of the other ideas from the thread. Thanks all I'll be in touch.

 

slow going around here had some **** weather to contend with. Got a tank full of 91oct and 15oz of booster (bought a case of it and will keep the tank rich with it). should be moving through the carbs soon think it will take some time to replace what's in the outter carb bowls but as the weather clears and spring should be able to nail it more often. Seems to be cranking up quicker though. Got some more to do. Stoked. Do want to get a reading on the max advance.
In the mean time I hope to learn how to get some pics off my phone to the forum.

 

if you look closely, there is a little picture of a mountain scene next to the smiley face and paper clip, click on that, it will ask you if you want from device, take a photo, or my albums. if the picture is on your phone, choose my device, find your picture, select your picture, i will go through a percentage until it reaches 100%. once it does that, click the gray box in the top right corner that says upload. once your picture pops up, you can type your message below it, then click submit reply. good luck

 

 

I appreciate the help, I will figure this out. New I phone Android user New Windows 10, brain freeze, I'll get it eventually haha, thanks again

 

The pinging may be why it had such cold plugs when you got it. Was it pinging before you changed 'em?

 

I'm wondering what part of the world you are in. The 91 octane fuel makes me think it may be a higher elevation. Try for some 93 if it's available. Don't let the engine ping as a normal occurrence.

 

It moved through the first time that you drove it. If it is still pinging, stop driving it until it is fixed.

In order to buy AV gas, you will need a 5 gallon container. You will not be allowed to pump into your tank. Or, drive to a drag strip for a test tank where you can pump directly into your car.

Use a dial back timing light to set your total timing. Start at 32 degrees total advance. If it still pings stop driving it and report back here for the next step.