[will slow gto]

Zero to Hero! Great job Dennis!

[SD455DJ]

Thanks Will! It was a lucky find (via post-toastie's thread), fun car to work on and learn about (the 350 HO). If it wasn't a local car, I would have passed on it, not to mention the local history and back story made it special for me.

Dennis

[KSZR]

Neat project, the story is too.

[HWYSTR455]

Subscribing! Still have to catch up though!


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[SD455DJ]

Last year we discovered the current 7029268 Q-jet on the 350HO has some major issues with full throttle transition. We tested it on the 455HO in the '70 Formula and it stumbles and almost dies from lack of fuel. So, it needs a lot more attention and research to see what's up with it. In the meantime, I found a 7029262 Q-jet ('69 YH 428 application) at Norwalk that was in decent original shape, and we are rebuilding it to install and try tomorrow on the 350HO. It has its original 72 primary jets/45 metering rods, BE secondary rods in an 'M' hanger. We're keeping our fingers crossed that this carb will work properly.

Dennis

[north]

I’ve often used the 262 as alternate on engines that were built with 268’s and never had any issue with performance or drivability. The only real difference is that hot idle vent thingy on the back. The 262 was also used on one other engine, the mid year 400-340 4bbl option on Catalina’s and executives. That engine and the 428-360 were the only 4 bbl’s that year that used the 400-290 2bbl small valve high compression heads. So that must be why they needed a different carb. They also used 066 cans but so did the GP 400-350 and 428-370 and those engines ran 268 carbs.

[SD455DJ]

North, that's what we thought as well...not much difference between the 2, other than the hot air compensator valve on the rear that can be bypassed/eliminated. The factory jetting is close enough to start with and we'll tune with more miles under its belt. I forgot about the B-body 400 4-bbl option with the small valves and high compression.

We'll check all the passages to make sure there aren't any blockages and install a new float as well along with a fresh rebuild kit with accelerator pump and gaskets.

Dennis

[north]

I’ve had good luck in recent years with accelerator pumps from quadrapower (I think that’s the right name). They seem to be holding up on several cars for several years now and in Southern Maine there is no ethanol free gas on offer. Most stock engines seem to like the factory sized jets and rods but occasionally I’ve had stock engines that just seem to need richer carb settings, don’t know why, some are just that way. Maybe dirt in the carb or something off spec in the engine innards??

I just bought a Custom S 2 door hardtop yesterday btw. Unfortunately just a 350-265. Typical options (auto, AC, p.s., manual brakes, clock etc. It’s a real survivor though, 32k miles, mostly original paint. Zero rust and super minty interior. As per my pattern it is brown (all the survivor cars seem to be green, brown or gold ;-)

[SD455DJ]

Looking forward to seeing your new Custom S! You know how to find them, or they know how to find you.

Here's a picture of the original owner of my Custom S with a '69 Tempest post coupe that I like to think is another 350HO... could be?

Dennis

[north]

Super dry car. The marks in the carpet are just light reflection. It has the Custom S non-perforated headliner and it has the non retracting wipers. No decor group evidenced by the lack of drip moldings, wheel opening moldings and pedal trim. However it does have the wood grain dash which I find odd since I don’t believe that that was a stand alone option?

It has a lot of original documentation but I’ll get a PHS to see what were the factory options. It does have tinted glass all around and deluxe wheel covers, remote mirror and four factory mats.

I noticed it has a different looking brake pedal pad with a horizontal space. Unlikely it was replaced, perhaps related to manual brakes or lack of pedal trim option? Car is rather late production in Arlington. It has the correct dark grills of late build cars.

The white letter tires have got to go!

[north]

Rear package shelf looks like the jute variety so must have had a factory ordered rear speaker for the AM radio. Virgin speckle in the trunk.

[Shiny]

!!!!!!

[KSZR]

Neat cars!

For those of us that aren't great with a carb, where do some of you recommend sending a Q jet for rebuild?

[north]

Honestly I do it myself mostly. The factory shop manual offers a great step by step process to go through all the components. If I start with a carb that runs decently I just do a disassembly and clean every with a can or two of carb cleaner and then reassemble carefully. This should correct most minor leaks and poor operation. If the carb looks really cruddy inside I give it to a friend who’s got one of those sonic vibration cleaners first. Quadrajetpower sells good quality kits but the hygrade kits at the local auto parts work well also. The one thing you really should buy from quadrajetpower is their accelerator pumps, they are bulletproof.

The key to success is careful attention to the cleanliness of all the little bits and the exact adjustment of things like the float, accel pump, choke linkage etc as per shop manual. I bench set the idle screws at 4 to five turns and then tweak them (while keeping track of turns so both sides are roughly equal) with a warmed up engine to achieve maximum vacuum signal.

Every now and then you just run across a carb that can’t run right. I just move on. As for Qjet morning sickness there is no long term solution but a light coat of epoxy over the bottom side of the bone stress cracks helps for a year or two.

[SD455DJ]

Very nice Custom S hardtop coupe North! That brake pedal pad sure looks correct...definitely familiar looking. My '70 Tempest with power drum brakes (decor group not ordered) looks to have the same pad design.

Dennis

[SD455DJ]

Originally Posted by KSZR

Neat cars!

For those of us that aren't great with a carb, where do some of you recommend sending a Q jet for rebuild?

Like North, we rebuild our own Q-jets...they are fairly easy to do, just take your time and follow the directions. You should purchase Cliff Ruggles excellent book on rebuilding and modifying the Quadrajet carb "How to Rebuild and Modify Rochester Quadrajet Carburators" (CarTech Books - SA Design Publisher).

I just rebuilt a recently purchased '69 7029262 Q-jet for my 350HO Custom S this morning and test drove it this afternoon. It's a very straight forward design requiring a little care and patience. Take pictures before and during disassembly to aid in reassembly. There really aren't a lot of parts to deal with. We also have a carb cleaner bucket (5-Gal. bucket that you can get at any auto parts store) that we use to soak the carb parts in for a good week before working on them. It's very satisfying to get the carb running well again. Fortunately, it didn't need anything extreme (like new throttle shaft bushings or leaky bottom plugs) or have any damage.

Dennis

[SD455DJ]

Speaking of rebuilt Q-jets, we can report that the new 7029262 is working flawlessly after the soaking and rebuild. The secondaries open without a bog and the engine runs clean up to the 5400-ish rpm automatic shift points (don't worry, the aftermarket in-dash tach reads 500-600 rpm high). The shifts were surprisingly crisp and firm and we're running 93 E10 fuel with a slow advance curve in the distributor (36 degrees by 4500 rpm with the factory heavy springs). Not a hint of pinging or detonation and it can burn rubber now! We will play with the advance to bring it in a bit sooner, but it runs great as is for now.

I have a video, but don't know how to modify/attach it (MP4 from Samsung 9 phone).

Dennis

[Verdoro 68]

I had no idea those 350s could wind that high. Maybe I'm just used to maxing at 5k on my stroker.

[SD455DJ]

Originally Posted by Verdoro 68

I had no idea those 350s could wind that high. Maybe I'm just used to maxing at 5k on my stroker.

Ken, That repro tach reads proportionally high, so as the rpm goes up, so does the error. At the 6000 rpm indicated, it's actually 5300-5400 rpm...shifting automatically. It does sound good revving and doesn't seem to be running out of steam with the 067 cam at shift point. It seems to be a good cam in a high compression 350.

Dennis

[Verdoro 68]

Ah, I missed your comment about the tach reading high and did a double take on the pic of the tach. 5400 is still a bit higher than your typical 400. Stout little engine!