Author Topic: Need some help and parts for my 17058213 Build for my Big10 Truck from 1978  (Read 38 times)

Offline Kent

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I have a nice core here and I would like to build a perfect carb for long trips with my BIG10 1978 with camper top. So gas mileage and also torque are most important if I haul a trailer with a car etc.


I bought Cliff´s Book but I didnt had time to start to read it and I will be in the US in 3 weeks so I would like to order some parts to my address there.

What would be the perfect setup for such a carb. I miss the divorced choke also. Otherwise my engine was overhauled and recieved a RV Cam and Headers. It has good torque.

So I would need to buy a kit that will allow me to work on my carb when I´m back from the USA and I hope I dont need more parts then.

What kind of tweaks are ok and necessary? Here is a list of some stuff a guy on Ebay is doing. Is that all good?


...throttle shaft bushings replaced with 5/8” wide Oillite bronze equivalent..permanently eliminate vacuum leaks past shaft ...stainless steel screws and Locktite on reassembly...throttle blades indexed to factory positioning in both bores...very smooth throttle movement.
...all primary and secondary fuel well plugs sealed with 2k epoxy…oven cured.
...base plate sealed APT plug and screw have been carefully removed and replaced with a external screw. This allows exterior adjustment to the part throttle air/fuel ratio. Nice tuner mod to take advantage of the “B” primary rods taper up or down sizes in their jets…very nice mod.
...idle mixture holes enlarged to allow full range of idle air/fuel mixtures., just like the earlier versions.
...slightly modified idle tubes and idle channel restrictions.
...accelerator shooter holes slightly enlarged and tested to spray two fast solid streams...accelerator pump duration shot linkage added to allow fast changes.
…main and idle bleeds reworked.
...secondary air flaps "notched" to allow instant spray under full throttle...secondary Pull over enrichment holes enlarged for a richer initial shot of fuel...secondary fuel well restrictor holes enlarged for faster refill after a full throttle RIP...secondary emulsion tubes and channels slightly enlarged to eliminate the “dog-leg” restriction...primary to secondary linkage adjusted for fastest response…CFM limiter tab carefully removed and modified for a adjustable set screw...set it mild to wild just by turning a screw for maximum 750 plus CFM flow…these mods will eliminate any lag/bog under full throttle.
...70 primary jet …45 B primary rod.
...secondary rod CP (.057”)..hanger I.
« Last Edit: Today at 04:08:15 AM by Kent »

Offline novadude

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My $0.02.



...all primary and secondary fuel well plugs sealed with 2k epoxy…oven cured.

Not necessary in most cases.  If the plugs are leaking, epoxy is not the best way to fix.

Quote
...accelerator shooter holes slightly enlarged and tested to spray two fast solid streams...accelerator pump duration shot linkage added to allow fast changes.

Don't touch the accelerator pump nozzles if this is a mild engine and economy is the goal


Quote
secondary emulsion tubes and channels slightly enlarged to eliminate the “dog-leg” restriction...

Not sure what he is talking about here with regards to enlarging channels.  If he is talking about the angled channels that lead to the main secondary wells, You'd need to pull the bottom plugs to enlarge these.  Not necessary in your application (maybe not necessary in any application).

Quote
CFM limiter tab carefully removed and modified for a adjustable set screw...

Also not really necessary.  Just file the tab on the air door linkage a bit if the door opening is too limited.  The air door opening dimensions in Cliff's book are a good guideline for this.

Just my opinion...