Open Element question

[someotherguy]

I don't think so, I'll have to go look at my parts. I just guessed, since the plastic duct sticks out proud of the fender liner, it was what help the hose in place.

99% sure that while it pokes out, it just does so to enter into that hard plastic piece that snaps into the engine bay side of the fender. That long hose you see in the pic, I swiped off a '92, by the way - which would also have the inner fender ductwork as your truck does.

Looked it up as a '92 C1500 5.7, and yeah, it's the adapter piece #6 https://www.gmpartsdirect.com/v-1992-chevrolet-c1500--silverado--5-7l-v8-gas/engine--air-intake, where #7 is the air inlet piece you're removing. The adapter still attaches to the fender afterwards.

Richard

 

[PlayingWithTBI]

Looked it up as a '92 C1500 5.7, and yeah, it's the adapter piece #6

Thanks, I'll have to take a look at my parts. They'll probably work OK. I'm still wondering if it'll have enough flow with a 383 (well, only 377 with std bore), turning ~5600 RPM (Peak HP with its cam).

 

[df2x4]

At this point I want to see a test of every possible stock intake combination almost more than I want to see them vs an open element. I'm curious where the most restriction in the stock TBI setup is. I'm guessing it's that long fender duct.

My (likely incorrect) hypothesis:

Open element has least restriction but worst intake air temps, stock intake with fender duct removed and V6 non-resonator tube has second least restriction while maintaining cooler intake air temps, and the difference in restriction between the two with your setup is minimal.

 

[99xcss4]

Eh? In the several trucks where I've removed that inner fender ductwork, there's no need to make anything to hook the hose (or resonator) back up. There's a plastic collar that snaps into the fender and joins the resonator to the hose (or non-resonator style long hose like pictured.) Does your truck not have this piece?

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Richard

other then a junk yard where can I get one also I seen a ld 2500 (6lug) for sale at an online dealer site with a 305 that had one of them the truck looked like it was un-mesed with do not know if it came that way tough it was a 88

 

[someotherguy]

Thanks, I'll have to take a look at my parts. They'll probably work OK. I'm still wondering if it'll have enough flow with a 383 (well, only 377 with std bore), turning ~5600 RPM (Peak HP with its cam).

GM decided the full setup minus the fender ductwork was OK even with a 7.4 so I suspect you'll be OK once you pull that piece. They continued with the duct that sits in the core support that routes air into the fender, and then the rest of the setup. Again I'm no engineer but the smallest opening on that setup seems to be the inlet portion of that fender ductwork; at eyeball range it looks smaller than the bores on the TBI unit so that hollers "choke point" at me. Some actual measuring might tell a different story, but I also will side with "GM omitted it after a couple years, so we can too" mentality..

other then a junk yard where can I get one also I seen a ld 2500 (6lug) for sale at an online dealer site with a 305 that had one of them the truck looked like it was un-mesed with do not know if it came that way tough it was a 88

Which part? The long hose w/o resonator in my pic came from a '92 base model V6 truck (and I mean base model - rubber floor, vinyl seat, etc.) It was also sold as an aftermarket part for a while; you could get one off Summit's site for like $20, don't think it's offered anymore.

Another potential choke point is the flap in the air cleaner housing but that's only due to failure of the wax pellet portion that opens the flap once the engine is warmed up. I pulled an air cleaner housing off a '95 2500 that had no provision for the flap. You can also delete the flap but it takes some patching of the air cleaner housing to eliminate "hot" air leak points.

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Richard

 

[99xcss4]

yes the straight ducting/long hose my base is like the one you pulled from a 2500 it never had a flap

 

[someotherguy]

yes the straight ducting/long hose my base is like the one you pulled from a 2500 it never had a flap

Came off this very truck. '92 C1500 RCLB 4.3/4L60, base base model. You can even see the hose in this "new inventory arriving" pic since the hood was already long gone.

Fun fact: this is the only truck I can recall that came in with a good running 4.3 V6. I had no end of people calling for them, and this is the only one I had.

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Richard

 

[99xcss4]

That is interesting. I never put much thought into how the air in the fender got there. I just pulled up some parts diagrams and it looks like that duct you drew the arrow to was used in both the TBI and Vortec trucks. From what I can tell it's just a short little piece that directs air into the fender cavity. But... It appears the TBI trucks got some extra ducting inside the fender that the Vortec trucks did not.

TBI 350 diagram:
https://nemigaparts.com/cat_spares/epc/chevrolet/53c-c/03/tc03-015/

Vortec 350 Diagram:
https://nemigaparts.com/cat_spares/epc/chevrolet/54c-c/03/tc03-035/

was the 6.5 TD the same as the tbi ducting or was the fender wide open with just ducting in the core support like the vortec

 

[someotherguy]

was the 6.5 TD the same as the tbi ducting or was the fender wide open with just ducting in the core support like the vortec

Maybe someone else knows; the oldest 6.5td truck I had was a '93 3500HD which wouldn't have had the inside fender duct simply based on year. That truck gave up its fenders (among other stuff) to build my '94 3500HD.

Richard

 

[fancyTBI]

Came off this very truck. '92 C1500 RCLB 4.3/4L60, base base model. You can even see the hose in this "new inventory arriving" pic since the hood was already long gone.

Fun fact: this is the only truck I can recall that came in with a good running 4.3 V6. I had no end of people calling for them, and this is the only one I had.

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Richard

Are the mirrors some old “street scene” product, or just some cheap knock off?