NemesisC5

Yep covers the hole seen in picture and you could use whatever round piece works to attach and block the bypass. The water going to heater core exits the nipple behind the block off (closet to block) then returns through nipple closest to thermostat flange re-entering and mixing with the cooled water from radiator so there is still some mixing with heated water but much less. Your car will run cooler but take longer for heater to to be hot. If you don't care to use your heater you can tap and plug heater nipples. If you loop the lines the heated water will just bypass heater core and mix with cooled water thus not cooling at maximum potential but nonetheless much better than before blocking the bypass.

c5racr1

So if you block off the two coolant pipes on the water pump, how do you fill the system? Cause I put a loop in the system and the line coming from the over flow tank goes to the line on the water pump.

db2xpert

Thanks for those pics. Copied the smaller ones to a landscape Word doc and blew it up.

I will give this a shot. I have zero welding skills. Should cutting a small/thin piece of aluminum sheet with a tight fit and pressing it in work, or might there be a problem if it shifted and interfered with the thermostat?

Thermostat - Not concerned with street driving for heater, but bringing oil temp up before going onto the track.

Modded LS7, Currently running a 160 T-stat, cruising street temp is generally around 180, and 225 at the end of track TT session. Dewitt radiator. It's the 225 that I would like to drop about 30 degrees.

NemesisC5

You always fill the system at overflow tank. The coolant pipes from heater core merely eliminate flow to heater core.

NemesisC5

LG says they allow their race car to idle to get up to temps. I would leave out t-stat.

c5racr1

The hose coming from the over flow tank goes into the front pipe fitting you are eliminating. Look a a hose diagram for the c6.

NemesisC5

Any location in a pressurized system will allow the overflow/fill function to work. It expands with heat and contracts as it cools. Pressurized system raise the boiling point so as not to create vapor bubbles which will not scrub heat from cooling passages. You can connect the hose from tank at any point in system that is reachable and convenient.

c5racr1

c5racr1

Look a the hose attached to the coolant over flow tank. It goes from the bottom of the over flow tank across the top of the radiator. From there it goes to the front pipe on the side of the radiator and to the heater core. The smaller hose coming from the top of the expansion tank to the radiator is for the coolant to be put back in the tank in the event of over pressure or coolant expansion. If you remove the larger hose, which is used to fill the system, and block off the ports, how will the coolant system be filled?

I'm asking because I did this mod and could not find a way to fill the system. Corvette system does not have a radiator cap, and pitting coolant in the tank will not go through the small expansion hose on the top of the tank.

c5racr1

c5racr1

Doesn't that replace the thermostat and block the rear bypass opening?

NemesisC5

Certainly looks like it might. I've not seen one for the LS t-stat housing before. Who makes it?

NemesisC5

I kept my heater in use, however you can put a fill cap inline on your top radiator hose and/or plumb it to another accessible location.

c5racr1

Katech makes the above restrictor

fatbillybob

Race cars are gutted with no insulation and they are hot. The last thing they need is a heater core + it is just one more failure point, junk in the engine bay, and weight holding water high in the chassis. So there is a big and small outlets on the bottom of the overflow bottle that join into 1. There is a big and small outlet on the waterpump. So you could get all the racer benefits by removing heater core and plumbing. Keep the big hose from WP to big outlet on overflow. Keep the small hose on the small WP outlet and cut the hose and attach it to the overflow small outlet. Put in a Katech restrictor. I guess what will then happen is the motor will think the heater is on and then wp will bleed off coolant directly to the overflow tank because there is no heater core in the loop just as before. The big hose will then do what the big hose always did. There will be some kind of circulation from WP big and small hoses to the overflow which is just a waste of energy.

I guess you could waste less energy or WP bleed off by plugging the small hose or capping the small overflow outlet and plugging the small WP outlet. That would act like the heater core was off/closed I guess not calling for heat.

I think you need the big hose to overflow bottle unless you changed the overflow's design so you can fill and so the system can equalize and air find the highest point in the system. The smallest hose on top of the overflow looks to be just a air bleed line.

fatbillybob

So I think the small end covers the hole between the 2 steel pipes. The big end looks to be exactly the size of a Tstat with holes in it to display fully open. I think I can make that from delrin rod stock I have in my garage faster than I could source one from katech who does not show it on their website.

NemesisC5

It's on there for $49.99/each

http://store.katechengines.com/therm...ctor-p369.aspx

fatbillybob

Thanks! This thread has developed nicely. I learned a lot from many posters

NemesisC5

Looking forward to hear your results from the track.

Joshboody

I'm thinking to try this Katech restrictor/bypass block off... so supposedly should increase cool water flow decreasing temps. I take it the tstat doesn't block the bypass as well even when fully open?

I do street drive the car, but in AZ... and could always replace with tstat in winter if needed. Basically stock ls1 and I can see 235ish ECT on the track with 160 tstat.