tri power

[Ray G.]

Hello folks, I have a 69 427-400 and I don't believe these carbs have ever been touched. I have gotten prices all over the place on refurbishing them. Can you tell me what exactly they would do to bring them up to good running condition?
Thanks,

[Dino L.]

Re: tri power

Pretty tough question to answer, I would take time and call, not email the top three carb rebuilders and ask them what they will do for you.

[Russ S.]

Re: tri power

With only 19000 miles I would say gaskets and cleaning only unless you want them re-colored.

[Rich G.]

Re: tri power

A couple of years ago I had all three from my 68 L71 done. It cost around $900. But I needed more than gaskets and cleaning. Can't recall all the parts, but there were several. This was from a local guy who specializes in Holley carbs here on Long Island.

Rich

[Michael F.]

Re: tri power

unless you want to re-color them for judging, take them apart and rebuild yourself, very easy and best kits are from holley...good luck.

[Duke W.]

Re: tri power

Can you tell me what exactly they would do to bring them up to good running condition?
Thanks,

What non-good running condition(s) are evident?

Duke

[Ray G.]

Re: tri power

I really don't know for sure. Just that it is 45 years old and leaks a little. I would guess it needs a going through to see if it holds vacuum, replace gaskets, whatever should be done. The car is a survivor with only 19k on it. Really untouched. My wrench adjusted the mixture so it would run well enough to drive it home. Living here in new England it will not be driven until the Spring so it is a good time to get these things done.

[Duke W.]

Re: tri power

...doesn't sound like there are any major issues, but time takes a toll on gaskets and various elastomeric parts over the decades even with low mileage

The overhaul and adjustment procedures are in the CSM and COM, and "zip kits" that have the normal replacement parts are available and Holley makes the best ones for Holley carbs.

Pay particular attention to torque specs. A typical Holley problem is warpage of the main body/metering plates/bowls due to overtightening the bowl screws.

Duke

[Stuart F.]

Re: tri power

I recently did a set for my son's 69 L-89. The kits were from CC, but had no instructions or adjustment data at all. It's been many years since I last touched a Holley (I hateum) so I had to dig deep in my memory banks and notes. The ends were a piece of cake (if you have clutch head screw drivers), but that middle one is not so simple cause that's where the adjustments come in. Holley uses a lot of "bending" of this lever and that rod to try and get the darn choke set right. I did not have it quite right on my first go round, and my son couldn't wait to test ride and open up those suckers. Well, he came back and said "it wanted to die at stop lights and it didn't want to shut off"! Oh, Oh, I hate it when they do that (darn high compression)! And he still hasn't afforded me enough time with it To tweak it right. This one's going to auction next month so, unless he wants to be embarrassed in front of a large TV audience, he best let me finish the job.

Stu Fox

[Duke W.]

Re: tri power

AFBs are the same. There are several bench adjustments that involve bending links and tangs to get specified measurements that you do before installing the carb.

Did you have proper Chevrolet service and overhaul literature for those Holleys!

Duke

[Ray G.]

Re: tri power

Thanks Duke and everybody. I am taking the Carbs to a well known rebuilder next week and let him do it. He has a good reputation so I hope all goes well

Ray

[Stuart F.]

Re: tri power

Ok Duke, i'll be a little bit more specific in my "tirade"; 1) AFB's at least adjust high idle with a screw on a cam, not bending a tab within a plastic cam like the Holley. 2) The choke linkage on the tri-power center carb is a divorced type with a link between the coil in the stove and the linkage arm on the carb. This link (rod) has two 90 degree bends in it which are not easy to bend in a manner to bring about an adjustment that can be maintained (IMO). 3) The tri-power linkage is, as we say in central Florida; pure "Mickey Mouse". To be more specific; the micro thin linkage that is supposed to provide a safety link between the end carbs to ensure their closure. The instructions tell you how to adjust the length of the linkage in the rear carb so that the bend in the link is slightly less than an amount to allow it to slip into the hole in the linkage arm (or words to that affect), but where does it tell you how to position the linkage in the curved slot of the center carb? Mis-adjustment of this small linkage can cause one or both of the end carbs to hang open slightly at idle. This is one thing I found that L-89's don't like much. I happened on my son standing by his car watching it "run on" after he thought he had shut it off (a very new experience for the young).

Stu Fox

[Duke W.]

Re: tri power

Ok Duke, i'll be a little bit more specific in my "tirade"; 1) AFB's at least adjust high idle with a screw on a cam, not bending a tab within a plastic cam like the Holley.
Stu Fox

Well, you might have to bend the link to get the fast idle cam index lined up with the fast idle screw with the choke valve fully closed, but I never had to mess with that adjustment. and I share your opinions of Holley carbs. I never understood why Chevrolet abandoned the AFB for Holleys.

The late Dale Pearman used to refer to them as a "packaged leak.".

Duke

[Patrick N.]

Re: tri power

A couple of years ago I had all three from my 68 L71 done. It cost around $900. But I needed more than gaskets and cleaning. Can't recall all the parts, but there were several. This was from a local guy who specializes in Holley carbs here on Long Island.

Rich

Same for me- I had my 68 L68 carbs rebuilt and replated, about $300 each. County Corvette in Westchester PA managed the rebuild- I think they use a guy in FL. Very good work, very nice results.