Vortec 4.3 v6 chevy intake mod,wood gas plentom under the carb.with spider injection intake manifold/untested

spider vortec v6 plentom/ how would i keep the carb from fast idleing with the floppy throtle plates from air and and gas control from wood gas plentom.or would it still work with throtle body type type throtle plates.It looks like one would need ball valves to control the air in, and have the other two ball valves closed from gasifier systom,in order to maintain the proper vacuem too the carb,not much in the book other than i did see one thing i will change is the carb bolts come up from bottom,instead of welding nuts to plentom,Thanks Chris Saenz,on the extra design ideas.PS the notch in the intake plenton was added to make room for the 80s distributor.I think i could have used an old points distributor,without haveing to weld the aluninum block to the intake, that would be the easyest way to use vortec spider intake.

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Replaced the nuts with studs,less app too corode,or rust any threads, got the slag all off and then painted with rustoium barbique paint, cooked in ovon at 350 f for 45 min, or so, allso put studs on all the bottom plentom bolts too make easyer for RR.THANKS

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Good morning Kevin .

I may be having a little trouble following the thread …

It looks like you plan to use a compartment below the carb to bring the wood gas to the motor. I can see how the carb will function but I don’t understand how you will throttle the wood gas .

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Wayne is right, you’ll need a single point of entry for the mixed air and gas. Your picture seems to show four…?

HI WAYNE,Thanks for responce. Just wounderd how bad the standard home made wood gas throtle plates would seal while trying too run on petro, I think i would move two of the lower plentom throtle plates, and open the the other two air valves on the bottom plentom for wood gas.I probbly missed something on the carb setups, but i am thinking the throtle plates on the plentom for air control, would work with less leaks while on petro,if they were some sort of ball valve,VS the throtle plates.

I dont understand the real differance between the above and below the carb problems, That might make a good thread in itself . In my case i had too make a plentom anyway,due too the spider intakes are like a standard intake with the top half of the intake cut off. That could be good when above the hood space is limited,for the carb setups. waiting for intake gaskets too get here, raining this morning

HI there chris saenz, i can see now i missed the boat on carb setups, i can use the other pipes for pop offs and block them if needed,in other words it wont work like it does when above the carb or when controling through the air cleaner above the carb, what would be the gain by useing the single port and pipeing the air in with the wood gas pre plentom, I did see your truck vidios on your pluming, wasent sure why it was plumed that way.Thanks

It seems if i bring the gas in the side of the intake,i am right on top of a dual port,too the point it would probbly get more gas in one side of the motor,maybe i should bring gas in above carb too get more even gas flow,due too the spider intake setup,whare as its not the same as when the plentom brought the gas in from the top of a standard intake.THANKS

Wayne’s standard setup brings in gas and air from four points, mixes them in the air cleaner housing, and feeds them through the original throttle. For this setup the gas / air must be mixed before the throttle. It’s possible to throttle them separately but this is far more complex…

If you plumb it in under the throttle body the way you have it now, as soon as the woodgas comes in the motor will run away (overspeeding), because it has a wide open supply of fuel and air and no throttle…

My setup had a single point of entry, single throttle body, which adds a second throttle pedal. The air and gas are mixed before this point. I recommend this setup exactly for you.

If it were up to me, I would cut off all four pipes and weld them shut, and instead weld on a 3" pipe leading to a 3" throttle body, and build out your air mixing beyond that.

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I gess i should have not put pipes in my half intake ,and built a plentom above the half intake. I can replate the pipes in the half intake,then what is the perpose of single port going too the plentom when it is in the proper location too the intake.Thanks/ PS good thing most of this build is the same as the fuel injection motors.

Thanks chris and wayne,I think i see the reason too the single port with carb set up,simplicity for throtle control,and a less linkage.and the air mixing befor the throtle plate.I am heading out too plate the pipes in my half intake,and build a plentom above the intake below the carb.And i am deleteing my plentom pictures to avoid confusion, untill the changes are made.Thanks.

I echo all Chris says .

Any control valve or throttle body feeding the gas to the compartment under the carb will have to be very air tight .

FUN FUN FUN AND STILL NO T BIRD / 4 days counting today,/plentoms and intakes/And odd ball motors,THANKS FOR THE HELP, I SEE THE SPARKS FLYING NOW.

MADE ANOTHER MOD /WENT TOO ONE INLET 3+ “/ the only thing i am going too add is a plate under the gas pipe too make the gas drop to the lower plentom ,in the center of the intake ,so that it gets fed from the center .like as if it was a carb sitting in the center of an intake.`

<img src=”/uploads/default/original/2X/6/6367fb3aede1dc88ae4e4c6d6e98f31bf41151b2.JPG" width="6

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I like it Kevin… Now you get to pick out a nice throttle body to go on the 3" pipe. Wayne gave me the one I had, I think it was off a Toyota truck. Anything that matches the 3" diameter. Of course this will need a second throttle cable and pedal in the cab.

If you’re really into linkages, you can make both throttles work on the same gas pedal. Max Gasman has described this in the past, and I attempted to demo it with a LEGO model.

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Thanks Chris on the how too’s ,I ben saveing a thotle body,its about that size and yes the linkage is a good little tric for dual fuel,neat idea, I am hopeing this motor is going too work out,found water in oil,hopeing head gasgets fix it,as they seemed baked bad around some of the water jacket areas,and the bearings look kinda scored,though the clearance so far seems too be about 2.5 thousans on the rods with plastigauge,not sure if that is an ok clearance,got too find the book for that year motor.motor bearings in the mail,hope they are stock size.

That is a pretty sweet design, is that going to be part of your vacuum project? Like have the diaphragm move the ratio linkage?

As an aside, you can 3d print lego pieces now. Their patent expired. :slight_smile: Which probably isn’t important… :slight_smile: But you could 3d print, then cast the body…

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Nope, only applies to under-carburetor setups. I will have a woodgas throttle linkage that moves in tandem with the MPFI throttle.

You could certainly do them together, but they are different projects and basically unrelated.

Got my spider intake about done for now,had too switch motors,the other motor has the cast iron quaderjet intake,from 91 astro van,V6 4.3. THe other intake is a later option,THANKS FOR THE HELP, now an under carb plentom for the quaderjet intake.This time only one 3" wood gas intrance.like it should have been the first time,Thanks

Wow Do you have a whole pocket full of 4.3 V6s. You just reach in and grab another one?? I have one spare but it is used up. It was the engine I did my original work on and gummed it up with tar and broke push rods a couple of times. It probably runs yet but I know I never got all that “guck” out of it. I watching your every move with interest.TomC

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HI tom C I pulled one out of two older asto vans, and the motor i just was going to buy just became a core motor,as when i drained the oil out of it ,it had whit stuff in oil so i pulled the pan and the head too check bearing,and the heads and gaskets for water leak areas.so the motor i was going too install,needs bearings.as they were scored bad from water in oil.and all new gaskets.bearings,not a ready too go motor as planed. so i got one of the old astro motors for spare,think it just needs lifter or rocker fell off.So i might go junk yard get another core older astro 4.3 motor for roller lifters and intakes for carberators.if i can find one not locked up.with extra good parts.