Author Topic: remanufactured.... well shoot.  (Read 927 times)

Offline rambojoe

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remanufactured.... well shoot.
« on: July 29, 2019, 07:58:03 PM »
hello all, since it was a rather long day I need to skip the normal intro and jump straight into the issue.

1977 g10 350 with the 4 barrel- 430,000 miles and the crank gave way. when it failed the gauge shot up to 300f, just south of catching on fire (I know, 2 hard to swallow statements...) original 350th rebuilt and new crate installed. the temperature warped the heck out of the air horn and I have no doubt it would crumble if it was straightened, and the warping is proud of 3/16" so decking it wasn't too worth it to me. of course after I found this sight ive since heard of the problems with remans, and this one is NO exception! tmrw I will go into the bad things ive found but for now the main issue is the apt.

my original apt is at a skinny 3 turns out from all in. the new one is not threaded and at the same reveal as my original when screwed all the way in. so my options are-


-well scratch this option because at least the air horn on the reman are older numbers (circa 1974) and ive already transferred my secondary pulloff cam and needles...(as well as my primary things)....

-use the original middle horn (throttle body horn) which isnt too crooked... i mostly bought the reman for throttle shafts that didnt leak.... not that the reman has re- bushed shafts :( but ill get into that crap later.

-shim a .089/.09 on top of old smokey, but it would need an epoxy to keep it form tilting on the apt and changing the setting...


minus a couple of reduced circuits which are easy to fix, i can make it work either way. im just curious for input and everyones experience. of course this is my work truck and its been 2 weeks of find this, cant find that, god i hope this crate motor is a 1/32nd as good as my old mill- fellahs, i got to get back to work and pay for it all! but, my whole life things have been done right (so far) and this van is always out in the hottest boonies of arizona...


thanks for reading folks...

Offline rambojoe

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Re: remanufactured.... well shoot.
« Reply #1 on: July 29, 2019, 08:17:38 PM »
oops... my bad. 750 cfm M4MC... :) original numbers are in the neighborhood of 1705ish- ill report all the juicy stuff tmrw.

last curious bit is the black top hat looking thing adjacent to the apt next to the float bowl. the reman didn't have one but ill be putting it in tmrw- what exactly does it do? is it a high altitude thing? California thing? or something that assists in readily available fuel for transistioning?

Offline Cliff Ruggles

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Re: remanufactured.... well shoot.
« Reply #2 on: July 30, 2019, 02:12:02 AM »
I try to do everything in my power to avoid anything commercially "remanufactured".

It is far better to source out an unmolested crusty old core and completely/correctly rebuild it your self than to waste time and funds on hacked-up over the counter junk.  There are still plenty of them on Ebay, and many still dirt cheap.

I tell folks this all the time.  They do things to those carbs that is difficult, if not near impossible to correct.  The acid bath is the first death sentence for them, it softens up the material.  They ALWAYS leak at the bottom plugs right through whatever sort of monkey-chit they dabbed over the plugs.  Then they start drilling away on the air bleeds, and driving in lead plugs for the bypass air.

The power piston hanger arms will be bent up, down or both.  Cheap ars parts used, and not even the correct parts.  About half of them will have the threads for the fuel inlet seat drilled out and some goofy POS double "O" ring deal pressed in there. 

My time is way to valuable to spend it polishing turds, so I don't work on them here when I can turn out 2-3 original units with the same amount of effort with perfect results in all areas.

I just had a customer send me a "reman", he didn't mention that fact when we talked over the phone.  I took it apart, complete pile of bovine excrement in every respect, so I tossed it aside and fetched a virgin core from the core pile instead.

That's how I typically deal with those problems here, I hope you have better luck with yours......Cliff

Offline rambojoe

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Re: remanufactured.... well shoot.
« Reply #3 on: July 30, 2019, 04:16:11 AM »
well I wish I knew it would be a waste of $370... and why we can only get "hot rod crap" instead of a oem spec carb you don't have to tune... the ol van has been such a torquey work horse for so long.

any idea what the plastic top hat looking volume displacer next to the float bowl is? ill assume its needed in the new one?

sorry people are sending you junk... I have to make it work for now though. should I use the original middle horn to retain some sort of adjustable apt? thanks folks

Offline Cliff Ruggles

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Re: remanufactured.... well shoot.
« Reply #4 on: July 30, 2019, 04:32:17 AM »
The plastic cup just fills the aneroid area to help prevent fuel "slosh".  I have a later carb on my engine and the car runs over 120mph in the 1/4 mile so it leaves hard enough to give you a nose bleed and I've done some pretty HARD braking on top end and it's never grumbled once and I'm not using that part in the carb.

I've had some folks tell me that if the cup is left out they have experienced minor flooding issues on hard braking, so it may be best to leave it in there, and certainly at your power level a little less fuel bowl volume isn't going to be missed.

One of the biggest problems with the remanufactured stuff is that I can't help you get it running correctly.  They are so "butchered" up and far from the standard calibration it's usually a lesson in humility to try to effectively tune one.

Sorry to put a big black cloud over the project, it's no big secret that I hate those units and it's typically a lottery ticket if you get one that works at all, let alone works like it's suppose to!  I mean come on now, every single one I've ever pulled apart has the living chit bent out of the hanger arms.  They are NEVER level or even, and those carbs use tapered metering rods so to effectively feed equal amounts of fuel to all 8 cylinders they MUST be exactly even.

So we straighten out the hanger arms and make them even, then notice that the PP spring looks like it came from a ball point pen, and replace that POS.  Then we notice lead plugs driven into the bypass air holes, then they drill out the lower IAB's to some HUGE size, then install huge idle tubes, then a tiny little N/S assembly, then pound in brass restrictions into the MAB locations, then "generic" jets and metering rods usually not even stamped with the size on them, crappy pump that's usually just an old rusted one with a new seal on it and old springs, then.....well, you get the point.....JUNK in every respect.....IMHO......Cliff

Offline rambojoe

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Re: remanufactured.... well shoot.
« Reply #5 on: July 30, 2019, 06:42:58 AM »
thank you cliff- yeah, I don't feel like its a black cloud or anything, it is what it is. ill use my old middle horn just to be able to utilize the adjustable apt. the top horn doesn't seem too bad- its easy to see whats been reduced or restricted because its brass.... ill make a list later but a few ridiculous thins have been;
air horn screws not tightened
no float needle retaining wire
the filter housing torqued to about 250lb...(not really)
the secondary holes in the carbs are horribly egged out...

just a few things.

all of my jets and needles are getting transferred over. the van always did great on towing power and could easily get on the freeway (towing or loaded with racebikes) on just the primarys, the secondarys were always just for fun and embarrassing folks who ruin their vehicles with dumb add-ons :)

just to be a resource for 1970's G10 owners ill spec out the original specs AND specs from the pos reman...ive been roadracing and building Japanese racebikes for a long time so rest assured, ill get it to work- reliably of course which is paramount!

I cant wait to get my hands on your manual- I feed on stuff like that!

thanks again Cliff and co, back to work....