GMPP 12496820 Carb to TBI
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GMPP 12496820 Carb to TBI
Well, after reading THIS thread and watching the linked video, it got me thinking about my latest intake purchase. Based on some of the discussion of what the intake may or may not have, and to help me understand what will need to be done to make this work on my L03 with L30 Vortec heads, I thought this image might help. Please feel free to tell me if I have something labeled incorrectly, or if you can fill in the ??? items. I skipped labeling the 8 intake bolts, and the carb flange.
#4
Re: GMPP 12496820 Carb to TBI
What you have labeled "??? Linkage Bracket ???": Front hole is for brace to alternator on my K1500. Rear hole I don't know. Potentially the two threaded bosses could be used for an A/C compressor bracket or somesuch.
"Temp sensor / TVS??? Forward Facing" is for the Vortec coolant bypass to the Vortec water pump.
"??? A/C Compressor or belt tensioner" I haven't seen used on pickups. My stock TBI manifold has the boss, but it's not drilled and tapped. I think it's used on vans; and perhaps cars.
"??? To or From Heater Core ???" is the outlet TO the heater core, it cannot be "from" the heater core. The heater core return hose would connect to the radiator "cool" tank, or to the water pump. Be sure to use a restricted fitting in that port, so the heater core does not get full water pump pressure. Makes a difference at higher RPM.
You've got no place to mount the EST module, EGR solenoid, or MAP sensor, which are all on one bracket on my K1500, just ahead of the EGR valve.
"Temp sensor / TVS??? Forward Facing" is for the Vortec coolant bypass to the Vortec water pump.
"??? A/C Compressor or belt tensioner" I haven't seen used on pickups. My stock TBI manifold has the boss, but it's not drilled and tapped. I think it's used on vans; and perhaps cars.
"??? To or From Heater Core ???" is the outlet TO the heater core, it cannot be "from" the heater core. The heater core return hose would connect to the radiator "cool" tank, or to the water pump. Be sure to use a restricted fitting in that port, so the heater core does not get full water pump pressure. Makes a difference at higher RPM.
You've got no place to mount the EST module, EGR solenoid, or MAP sensor, which are all on one bracket on my K1500, just ahead of the EGR valve.
#5
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Car: 1988 Trans Am
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Re: GMPP 12496820 Carb to TBI
Thanks guys. While I've owned this car for many years, I have had to do nothing under the hood except clean. I really don't know my way around under there as well as I should.
Got it. Very hard to see anything under the hood with everything in place. But I can see a few anchor points for the coil in these photos, one shared with the cable bracket. Looks like I should be able to modify the cable bracket to work with the corner bolts on the Vortec intake.
Looks like those are unused on the factory TBI intake. I love the extra loose nut laying in the intake...had not seen that before. Looks just like the one on the stud in the foreground. I'm guessing they dropped one while driving the one on to the stud.
Good to know. As sold to me, it has a sensor in it, so mine was just a guess, hence the ???. Now, with Vortec heads, do I need to use that as the factory did on a Vortec engine, or can I just cap it off? There's nothing like that on the current TBI intake or pump.
Looks to be the same on my TBI intake as well.
Out of the engine TO the heater core. Got it. Thank you. Looking under the hood, I can see the Rube Goldberg-like heater hoses running here and there to the control valve. What a mess....something I already planned to attack. The only one I can't trace is the one coming out of the core, and it turns straight down. I'm assuming it's attached to the water pump somewhere/somehow, but I sure can't see it with everything in place.
Heater hose restriction...did not know about that. Thanks for sharing that info. In the "auction" picture of the intake posted above (the one with the intake sunning itself by the pool), you can see a fitting for that heater core hose. The fitting is smaller in diameter inside by far than the hole in the intake. Is that the sort of restriction you are speaking of? Let me go get a picture of that.
Yes, that was mentioned in the video, and I think you mentioned it above. Too congested back there for me to SEE what you are talking about at the moment, but I'll take your word for it. Something will have to be fabricated for sure.
I can also see how the TBI EGR is mounted now. Never paid much attention to it before. But I can clearly see that will have a new home (location) on the new intake. And I can see how that adapter might help. We'll see.
It also appears that the GMPP intake does not have a provision for the stud/nut that anchor the end of that alternator pencil brace. (Yes, mine came with a cross-threaded nut muscled into the now non-useable stud, leaving a gap to the pencil brace. Thank you Mr. Goodwrench.)
Got it. Very hard to see anything under the hood with everything in place. But I can see a few anchor points for the coil in these photos, one shared with the cable bracket. Looks like I should be able to modify the cable bracket to work with the corner bolts on the Vortec intake.
"??? To or From Heater Core ???" is the outlet TO the heater core, it cannot be "from" the heater core. The heater core return hose would connect to the radiator "cool" tank, or to the water pump. Be sure to use a restricted fitting in that port, so the heater core does not get full water pump pressure. Makes a difference at higher RPM.
Heater hose restriction...did not know about that. Thanks for sharing that info. In the "auction" picture of the intake posted above (the one with the intake sunning itself by the pool), you can see a fitting for that heater core hose. The fitting is smaller in diameter inside by far than the hole in the intake. Is that the sort of restriction you are speaking of? Let me go get a picture of that.
I can also see how the TBI EGR is mounted now. Never paid much attention to it before. But I can clearly see that will have a new home (location) on the new intake. And I can see how that adapter might help. We'll see.
It also appears that the GMPP intake does not have a provision for the stud/nut that anchor the end of that alternator pencil brace. (Yes, mine came with a cross-threaded nut muscled into the now non-useable stud, leaving a gap to the pencil brace. Thank you Mr. Goodwrench.)
Last edited by DynoDave43; 04-21-2022 at 05:03 PM.
#6
Re: GMPP 12496820 Carb to TBI
Out of the engine TO the heater core...
...Heater hose restriction...did not know about that. Thanks for sharing that info. In the "auction" picture of the intake posted above (the one with the intake sunning itself by the pool), you can see a fitting for that heater core hose. The fitting is smaller in diameter inside by far than the hole in the intake. Is that the sort of restriction you are speaking of? Let me go get a picture of that.
...Heater hose restriction...did not know about that. Thanks for sharing that info. In the "auction" picture of the intake posted above (the one with the intake sunning itself by the pool), you can see a fitting for that heater core hose. The fitting is smaller in diameter inside by far than the hole in the intake. Is that the sort of restriction you are speaking of? Let me go get a picture of that.
Photo of the quick-coupler, note how the coolant passage is restricted to about 1/4 inch, with a plastic divider cutting flow even more.
(Lower left corner of photo.)
It also appears that the GMPP intake does not have a provision for the stud/nut that anchor the end of that alternator pencil brace. (Yes, mine came with a cross-threaded nut muscled into the now non-useable stud, leaving a gap to the pencil brace. Thank you Mr. Goodwrench.)
However, since the angle the bolt goes into the manifold/cylinder head is different on the Vortec than the TBI, your "pencil brace" will need modification or you'll have to fabricate a different one.
Last edited by Schurkey; 04-21-2022 at 05:34 PM.
#7
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Re: GMPP 12496820 Carb to TBI
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