AWD 99 2 Door Tahoe Build

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0xDEADBEEF

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Could reducing inlet at the manifold help me out? I don’t see how it could as the outlet would determine flow rate but I’m willing to give it a shot if there’s a chance it’d reduce the pressure on that upper

I think you meant outlet ... reducing the outlet diameter will reduce the flow. I don't think it should ever be bigger than the inlet or you will lose pressure in the block.

Do you have the stock outlet and pump? I would try putting those on.

You could also experiment with the pulleys. You could put a larger pulley on the water pump or a smaller one on the crank to slow the pump down.

It's hard to diagnose and fix over the internet, for example you could have a head gasket leaking exhaust into the coolant.
 

Jnunez74

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I think you meant outlet ... reducing the outlet diameter will reduce the flow. I don't think it should ever be bigger than the inlet or you will lose pressure in the block.

Do you have the stock outlet and pump? I would try putting those on.

You could also experiment with the pulleys. You could put a larger pulley on the water pump or a smaller one on the crank to slow the pump down.

It's hard to diagnose and fix over the internet, for example you could have a head gasket leaking exhaust into the coolant.
I unfortunately built engine from the block so I don’t have any of the stock components… was kinda just piecing it together and hoping that I got it right the first time to be honest. But everything is brand new, I assume the head gaskets aren’t causing any blockages but if reducing doesn’t work I might pull it apart and see if a different set of gaskets does better
 

Jnunez74

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I unfortunately built engine from the block so I don’t have any of the stock components… was kinda just piecing it together and hoping that I got it right the first time to be honest. But everything is brand new, I assume the head gaskets aren’t causing any blockages but if reducing doesn’t work I might pull it apart and see if a different set of gaskets does better
For reference there’s the sizes
 

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Jnunez74

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I see now.

I would try a 1.25 manifold outlet so the hose would be the same on both ends or get a radiator with a 1.5 inlet.

The flow is going to be restricted going into the radiator and you are making the hose contain the backup of water.
Will do, I’ll get one ordered and let you know what happens with it. I appreciate the insight
 

0xDEADBEEF

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Will do, I’ll get one ordered and let you know what happens with it. I appreciate the insight

Hopefully it's as simple as the fix on my C5. It looks like it could be the same problem, the flow out of the block was just way more than the flow into the radiator inlet and the hose kept blowing off.
 

Jnunez74

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This weekend had some progress made. Had a bad miss that was alleviated by changing to a 90 degree boot going to the spark plug. It was nice to be consistently hitting on all 8. Had to do some mild tinkering with the timing as well, still trying to get used to the pro-flow system. Had to put some beefier throttle return springs on bc it would not register 0% throttle which had ecu bugging out. Finally managed to get the alternator to do alternator things, that was an oops on my behalf (assumed red would be field but boy was I wrong). Still waiting on a smaller water neck, hoping that will assist it in staying cooler but ima go ahead and get a non high flow water pump ordered bc somehow that is cheaper than buying a new, larger pulley from March performance.

As for the cooling issue, it has no issue at idle but as soon as it’s cruising for 15 minutes it creeps up over 220. As soon as I am not moving she cools right off so I definitely think it’s moving water too fast for the radiator to be effective.

It made its first trip to the gas station and boy do I not miss filling this 30 gallon tank… initially was told but my engine builder she would thrive on 87 but I’m getting spark knock so gonna have to siphon that off into the Camry and retry it with 93 next time I’m home.

On a side note I learned this weekend that the neighborhood I’ve lived in my whole life isn’t a race track… also was informed that my truck doesn’t have a tag (doesn’t have bumpers, lights or mirrors either). Gotta love when concerned citizens follow you and try to pick a fight.

On an unrelated note, is there anyone out here who could walk me through wiring my A/C without and stock harness being present. I’m sure I could figure my was though it but if anyone has insight it’d be greatly appreciated.

At this point I think it’s about to get slow, trying to scrape quarters together to pay my painter and window guy as those seem to be the next big step. Fingers crossed that I can have those dollars scraped together by late March early April so I can finally get that ball rolling. Can’t really put the interior together until he’s done spraying. Mechanically, 20 miles later she seems sound enough to press forward without having to make any further modifications.

I will be snapping some pictures of what’s going on to post when I’m home next. I have a terrible habit of not documenting what I have going on, so I have 0 pictures of the rig from the past month.

Next steps beyond the aesthetic portion of the build are getting a full bleed on the brakes, getting more than 3 lugs on each wheel, continued adjusting of serpentine system, ensure all lighting is still functional, cut out rear glass (planning on making a video on that), make a dash setting for an iPad mini and installing Tcase shifter
 

pdubya

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Holy cow, awesome job, the time and work involved? I have my old stock 94' at the shop now, getting some paint work done , and would love to just drop a 5.3 in there, but being a farm cruiser and toy, I'll have to keep the 5.7 a while. Good luck on yours!
 

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