[Greg Reid]

It's a Heinz-57 hodge-podge of finishes and a mix of original and repop ingredients but I think I have a mechanically sound '65 tri-power here. Got some good parts and advice from the folks in this forum.
It's going on a '66 engine and a '66 body so it got '66 metallic blue.







Today's Questions-

1. What do you think of what some previous owner did to the choke tubes? I'm afraid to grind it off and drill the tubes for fear it's a crack repair (brazed).



Inside the runner, however, looks undamaged?




2. How far, percentage wise, do you all prefer the center carb opens before the secondaries are activated? I'm at about 50%..anything beyond that doesn't allow 100% opening on the end carbs.

[Tom Vaught]

Choke tubes look good. Choke tubes are swedged into the holes on the intake manifold cross-over.
Whoever welded the ends of the open tubes (they will not leak if the upper tubes are not connected) so dumb aze plugged holes that did not need to be plugged.

I would try to cut off the stubs /plugs they put inside your choke tubes. Then you can insert upper tubes and the heat stove will still work fine.

As far as the linkage goes, you can mill the slot a bit longer on the linkage and drill a second hole in the rear arm or buy a double hole arm from Dick B and get more control over the center carb vs rear carbs opening and WOT timing.

Tom V.

[Old Goat 67]

Not bad Greg!

Gary said he didn't do it, he can't weld!

[GT182]

Yeah ya beat me to it Charles. LOL It sure looks good Greg.

Greg, no I didn't do it. And Tom, I'm not the dumb aze that plugged the holes.

[Old Goat 67]

Greg, grind those gobble-de-goop welds down and carefully drill out the opening till you get to the right diameter for the outer tubes to fit, otherwise every time you open the hood it will slap you in the face.

[Greg Reid]

Alright.. I'll grind them. I just couldn't think of a good reason to weld them up unless something was broken.. Didn't consider the dumbaze angle.
Don't worry Gary.. I knew it wasn't you...lol
Tom, or anyone, you know how far the center typically opens before activating the ends? Might be ok as is.. I just don't know.

[Tom Vaught]

40 degrees of Primary opening before the secondaries open is pretty common. That is about 1/2 throttle.

Based on the typical throttle angle of the throttle blades being about 12 degrees.

So 90 degrees -12 degrees = 78 degrees of blade travel.

78 degrees of total blade travel divided by 2 = roughly 40 degrees of travel to be at the 1/2 open point. Secondaries start to open at that point on a lot of Holley and Rochester carbs.

Tom V.

I apologize for the dumbaze remark.

[Greg Reid]

Sounds like I'm pretty close on the angles. I won't modify anything until I know it's needed.
No apologies needed Tom. I really appreciate the coaching and I agree on the dumbaze remark if they did all that brazing just to close up the choke tube fittings.
By the way, thanks again for the choke pull-off piston.

[Old Goat 67]

Looking good Greg!

Takes grit on your part, John Wayne would be proud of you.

[Greg Reid]

Well, I'm a southern boy Charles...I DO like my grits.

[Tom Vaught]

For a IOWA bred youngster that moved to Hollywood in California, Marion Mitchell Morrison (John Wayne) did well in his life.
True Grit being a favorite of mine.

Tom V.

Glad to help on the part you needed Greg, and that it was the right one.

[Greg Reid]

Alright, I drilled it out but was unable to save the tube.. Ol' dumaze can really braze!...lol...
I see that Mike has them at pontiactripower.com or might check with Mr. Boneske first but the long and short of it is that I plan to run it using hot air, as designed.

[77 TRASHCAN]

Thought you were going electric choke???

[Greg Reid]

I was but it was mainly because I was too chicken to grind that braze off. Now that I've done it and see no cracks or anything, I'll go with the original setup. Everything else I need to complete this is now coming in the mail. Found an original bakelite cover (they're not being repopped) with the spring for $15 on ebay and the tubes are coming from pontiactripower.com
I still can't believe someone went through all that trouble just to stop the ends of the choke tube up.

[77 TRASHCAN]

Cool!!!
I converted my Q-Jet on my car to electric, works awesome! Probably more awesome because I re-built the carb with Cliff parts and perfromed necessary mods for it to perform much better.
Cliff said the hot air setup works fine, you just can't have any vacuum leaks where the pieces of tubing connect, or obviously have your exhaust crossover tube be leaking exhaust gas into the carb vacuum source...

[Greg Reid]

I've used one of the e-chokes before and yes it does work really well.
The 389 I'm putting this tripower on is an original '66 GTO 4spd engine that came out of a 65 GTO that had been sitting in a field for many years. I mean this car almost broke in half when they moved it.
Surprisingly, the engine started right up and the hot air choke worked great on it. Even the heat valve on the manifold still worked. It was unbelievable. I still have the 4bbl setup on a cart in my garage. Choke tube is perfect.