Update on the Wagon 454 (sorry, long.. but technical)

[curtis73]

Boy did I have a killer day today. I made the right phone calls, hooked up with the right people, and I found a good old fashioned tuner to help me out with my 454 dial-in. This guy used to work for Galpin Ford, but his wife died shortly after their son was born, so he opened a private shop at his home. He has a great collection of emissions testing equipment including an old oscilliscope, a Sun distributor tester, and a host of other goodies.

We started out at 8am. I wanted some help setting the valves while running since I had never done it, and I needed help tailoring the ignition curve. We set the valves first (boy my headers are a mess). Turns out I had them right, there are just some that leak down a little fast, so the cheap lifters are not on my list anymore. #1 huge lesson: how to set valves while running the engine. #2 huge lesson: Don't skimp on parts store lifters.

Then he started doing some ignition things. He kept advancing it until it wanted to kick back on startup. He pulled the distributor and wanted to do some tests with the advance locked out. Since it wasn't a normal Chevy HEI (its a mallory billet HEI) the normal lockouts don't work. Not being satisfied with just wiring it closed, he proceded to braze some holes closed, then got out the drills and taps. He then machined two #10 machine screws to thread into the rotor base and be a press fit into the advance head. Absolutely stunning work and it was fun. #3 huge lesson: how to braze tiny little areas. Then we put it back in locked at 38 total. To the amazement of both of us, the only ping we had was at very low RPMs and full throttle, like during flash stall. At no other time did we have any. So, back to the drawing board for the vacuum advance. I had swapped TBs on my Qjet to get a ported vacuum source, but I found out that it was actuall venturi vacuum. Great for EGR valves, but pathetic for ignition advance. So, the carb comes off the first time. He pulls the TB, we mark for a good spot and drill a .0555 orifice into the proper cavity for a ported source. It worked perfectly. #4 huge lesson: how to add ported vacuum to a TB that doesn't have it. So, now we hooked it all back up and ran it to test it with the advance. We adjusted the vacuum canister all the way in (and noticed quite a bit of detonation), then just backed it out by one-turn increments until it was gone, then gave it another 1/4 turn to be safe. Ignition curve = done. 36 initial, up to 8 vacuum at part load, 37 total. Odd? Yep, but not a touch of detonation. The only problem (and its not too bad) is that when its hot, the flame speed makes some pretty tough starts with that much initial, but I don't think its of great concern. If I want to, I can unlock the centrifugal advance and just limit it to about 7 degrees. That way I can set it to 30 initial and still get my 37 total. #5 huge lesson: how to properly alter centrifugal advance curves.

Then we hooked everything up to the gas analyzer. He set idle mixture, and then noticed that the cruise mixture was off and (despite an adjustable primary step up,) we couldn't change it. Off comes the carb again. Here's where we had some fun. The custom adjustable setup was poorly executed and the spring on the adjustment screw contacted the piston making any movement impossible; ergo a fixed primary metering. We promptly fixed that with a smaller diameter spring. While we were in there, we swapped to leaner primary jets. I also used this time to re-engineer a weak point of the electric choke. Namely, it fell apart, so I tapped it for little screws instead of the factory rivets and brads. Back in it went and we did some more gas analysis. He wasn't quite happy with it, so we did one more jet change and it was set. #6 huge lesson: gutting a Qjet and customizing it is more common sense than I previously thought.

He also readjusted my door strikers since I had a door misaligned, ordered out for lunch, took the time to illustrate every single aspect of our day, and was able to talk TO me and not DOWN to me. He recognized the value of my knowledge and built on it.

When I left his garage 8 hours later, I had just gained hands-on experience in the last mystery of engine building for me; the tune up, and learned more about the finer points of engine operating parameters than I could possibly fit in my head. Not to mention, he charged me less than half of what I expected for the day. I ended up insisting on paying more for his time and care.

The result is that my car runs like a dream. Unfortunately during the tune-up I discovered a leak in the radiator core, but better now than halfway across Utah.

So, needless to say, if you need any work done in this arena, PM me cause I got his number

Thank you all so much for your help on this project. Its almost done and I just want to make sure I say a huge THANK YOU for all of the help you've provided.

Now...off to the beer.

[MagicRat]

Absolutely and completely fascinating.
I had to re-read that post a couple of times.
Wow. I have spent weeks on project cars just trying to tune it the way that guy did in one day.
Boy do I need a distributor machine and exhaust gas analyser!!

Very very interesting post. Thank you for the follow up.

[RandomTask]

Awesome post curtis, I wish I new how to do that stuff . Hope she (your car ) treats ya right!

[v10_viper]

Glad to finally hear that you got 'er runnin right Curtis...too bad about the radiator but like ya said, better now then later. I love it when you get to do hands on stuff like that and alter parts to get them right. Have a great trip!

[curtis73]

Way back when I started modifying things, I never was happy just doing what everybody else did. Not to make light of anyone's project since they are all worthy, but anyone can read Car Craft, buy the same Edelbrock, Comp, and Hooker part numbers and make power, but I always wanted to know how those parts affected the power so I could understand it. I think most of us in this forum are the same. Even the noobs ask good questions here in the pursuit of that knowledge.

Thanks for the words of encouragement.