TB coolant crossover,any disadvantages?

[efnfast]

Hey Jeff, wanna come up and watch, learn, help when I do this? I'm guessing multi days.
I've got a spare bedroom (good if anybody brings the wife) and two hide a beds. Anybody that comes is welcome to stay.

[Hog]

Originally Posted by scottfab

It does indeed uncluttered the look. For me where I live winter is
mid 40s most of the time and a bit high on humidity. Perfect storm for icing. Bypassing the TB is not for everyone and it is important to be clear about that to all. There are those that would propose that it is the cure for everyone. That's just like the "snake oil" salesman approach.

I have had a t-body coolant bypass stick at WOT before. Rev limiter til I turned the key off. Was a bad experience, almost caused an accident.
I dont do this mod anymore, at least where I live.

[efnfast]

I don't understand. How does removing the coolant from the plenum or IH cause the throttle to stick?

[scottfab]

Originally Posted by efnfast

I don't understand. How does removing the coolant from the plenum or IH cause the throttle to stick?

Who knows? Ice in there? Getting hot coolant up there to keep the grease around the butter-fly blades in the TB soft? Those guys that designed the LT5 are probably pretty smart. There's any number of systems that could be ripped out because how/what they do is not apparent. But just like bypassing the clutch switch, you may get lucky and never find out why it's there.
When in doubt spray some "AmZoil" on it or RIP IT OUT.

[rkreigh]

factory engineers are smarter than us. the bean counters, no so much. take for example the c4 radiator. plastic end tanks. so instead of designing a proper rad, the bean counters had lotus do the "bypass" cooling system.

think that's a smart way to go?? probably not.

as for the throttle blades icing, yes, driving it below freezing it can happen. but I've NEVER seen it. you can also drive into standing water and hydraulic a piston (that I've SEEN happen)

GM has to "idiot" proof their cars and design for ALL conditions.

but when you try and "out engineer" what GM does, it's best to understand what you are doing.

bypassing the coolant doesn't hurt anything when driving above freezing.

but it doesn't add horsepower, or save weight either. it's a "cosmetic" mod.

I tried all kinds of mods on my turbo buick to "cool the intake charge" wrapped tubin with a cooling supply around the intercooler, and intake tube, lots of rube goldberg stuff. it added weight and nothing else.

the intake charge is moving pretty fast and doesn't have much time to pick up heat. even the heat soaked intake doesn't hurt too bad, but it's certainly more of a source for intake heat that a couple inches of throttle body. ponder that one if you will.

GM mostly went to the nylon intakes on the LS motors to save weight. it worked. the intakes are smooth, flow a ton, and don't transfer engine heat to the intake charge. the high flow and smooth transitions in the intake really work.

look at the S shape of the LT5 intake. air doesn't like changing directions and turbulent flow. if we straighten out the path, we can pick up laminar flow and velocity into the port. love to have the $$$ to build a nice CF intake. hopefully I can get there soon.

[Dynomite]

Originally Posted by rkreigh

as for the throttle blades icing, yes, driving it below freezing it can happen. but I've NEVER seen it. you can also drive into standing water and hydraulic a piston (that I've SEEN happen)

bypassing the coolant doesn't hurt anything when driving above freezing.

but it doesn't add horsepower, or save weight either. it's a "cosmetic" mod.

Let me discuss this if I may

1. I concur with rkreigh and Hog that a freezing air flow at WOT can change the geometry of the TB as well as freeze any moisture in that area. Either could cause the TB blades to stick in any position. I am not sure if TB coolant flow heating could even keep up with WOT air flow cooling. I guess it all depends on how cold ambient temperatures actually are (are we talking 20 deg F or -20 deg F).

a. It would have been informative if Hog had just let the engine rest for a bit after turning it off to see if heat migrating upward from engine actually released the stuck TB blades.

b. Marc tested the TB function at idle at an air temperature of 20 deg F (90% Humidity) and found that the TB maintained 50 deg F temperature. This experiment is on his web site. As discussed in......Throttle Body Heat Bypass Line

c. Hog's situation is at WOT which is a completely different issue in terms of air flow and TB blade rotation.

2. The TB coolant is always flowing when the water pump impeller is rotating (except it TB coolant ports are blocked for any reason). That TB coolant flows to the "T" and to the radiator when the engine has reached operating temperatures. That TB coolant flows both ways (to radiator and coolant purge tank) when the engine is in the process of reaching operating temperatures. From this one can say........

a. TB coolant flow interferes with radiator air purging during the time the engine is in the process of reaching operating temperature.

3. Many guys and gals flush their radiators to increase radiator coolant flow. The debree/corrosion that decreased radiator coolant flow can also decrease/stop TB coolant flow (the TB coolant ports are very small).....

a. I wonder how many flush their TB coolant flow paths when they flush their radiators?

4. The additional issue that rkreigh did not mention (cosmetic mod was mentioned) is the advantages of TB blocking (actually Injector Housing Coolant Port blocked just below Plenum) for Plenum Removal......

a. With TB/Injector Housing coolant blocked you can install gaskets dry without having to concern yourself with being exposed to coolant flow. This means as in my situation I do not have to add permatex on the Plenum gasket and I do not have to torque my SS Allen Head Plenum Bolts all the way down to 19 ft-lbs.

b. This means I do not have to measure to determine when proper amount of coolant is drained to avoid potential Air Pockets (Air Locked Water Pump) when refilling with coolant.

c. What also cleans the clutter (cosmetic mod) of the LT5 is adding an Oil Catch Can (the Red Canister just in front of the Brake Fluids Reservoirs). This eliminates ALL the Plenum side rail clutter on both sides of the Plenum





There.....I said it....maybe should not have said anything

[efnfast]

Thanks for the input, but too late, I drilled and tapped the holes last night.

[Dynomite]

Originally Posted by efnfast

Thanks for the input, but too late, I drilled and tapped the holes last night.

Oh...chit

[efnfast]

It's all over but the cryin' now. So far the only bad thing I've heard is the TB sticking open, and we don't know why. That's my story and I'm stickin' to it.

[scottfab]

Originally Posted by efnfast

It's all over but the cryin' now. So far the only bad thing I've heard is the TB sticking open, and we don't know why. That's my story and I'm stickin' to it.

I'm sure all will be fine. And if it's not you'll not likely make any connection to bypassing the TB. And for sure you'd not likely share any side effect. I probably wouldn't either.

Let me add some mostly totally irrelevant side notes and bulky text to support my position.

1. The plenum gaskets would not stick even with the coolant going to the TB if you use 100% rubber gaskets.

2. If you know how to flush the coolant you wouldn't have any problems with clearing the TB of the MASSIVE debris that occurs there. (there is a hatch for this)

3. Coolant filling will now be an iffy job of lifting, tilting the car and shaking it so as to get air out that would have gone out as designed had you not bypassed the TB.

4. The next owner of the car will hopefully study and understand the lift and tilt routine.

5. Now you'll have some nice capped holes that look way better than stock (to some).

6. You can add some nice red paint to the plugs for extra bling It'll look so cool for a year or two then... not so much.

7. You now have empty passages in the plenum that can clog with dust and debris because they are not in the coolant path.

8. You'll save $ on not having to buy replacement rubber hoses for the TB but that is irrelevant.

9. Did you know that many move the air temp sensor down to the intake filter area to avoid the heat at the metal of the plenum? Must be because during a heat soak condition the plenum gets too hot and effects the air temp reading? Imagine how much hotter it will get now with bypassing the TB.

10. The lowering of weight by losing the TB line hardware is a bit offset by adding plugs.

11. Did you know there is a plate at the top of the TB that can be used for cleaning the passages?

12. Actually bypassing the TB is not that big a deal on the overall. But making up a bunch of lines of text for bulk is fun. =D>


Here is an image of a stock LT5 completely intact and working.
This will become a key factor in resale value now that the car is 24yrs old (on some). Mine was built in Sept 1989 !!
It's her birthday this month.