I tried again... is this a better option?

 

Yeah, that'll work. I think factories try to tee into the lower rad hose or lower rad area instead of heater hose.

 

Great diagram at the top of this thread....very informative read!

 

Thanks for the input, guys. I think I have 3 options, now. I talked to Bill at Ron Davis, and he actually recommended circulating the water through the tank (the way the stock Corvette system does). That's represented as second option, below. I've also added a third option which I think Terry was recommending, with the bottom surge tank line run into the bottom rad hose.

Thoughts? Shall we vote?









My inclination is to go with the second option - having the water circulate through the tank to remove air. As always, comments and suggestions welcome!

Cheers,

Dean

 

I think what Ron Davis suggested is not likely the same as your #2 option where you're actually short circuiting some of your coolant flow via the heater inlet/outlet. For roadrace cars and what Ron suggests is an air separator where the coolant flows through the tank and has a void space where any trapped air can accumilate and continuing flow is from the bottom of said tank (very similar to a dry sump tank but smaller of course). Actually your third option is one I've seen work well too. The basic idea is to have a place where any air in the primary flow part of the system can accumilate and not be re-introduced.

Andy1

 

If you are going to run a pressurized surge tank, the hose that is te'ed to the steam line and runs to the radiator should be eliminated.

If you need a hose tee that goes from the pressurized surge tank to the lower radiator hose, JTR has the parts:
http://www.jagsthatrun.com/Pages/Par...rass-Tees.html

 

I've already got a Tee on order with JTR, Mike!

 

My setup will look very similar to pic # 2. Only difference is I will have a heater core and auxiliary water pump hooked to the LS1 water pump.

Here is the coolant reservoir I finally settled on. Its a 20 Psi cap which I think is close enough to the usual 18 psi caps used in F-bodies and vettes.

 

Okay, with so many different "options", I'm going to need some help as well.

I'm using an aluminum cross-flow Summitt radiator with a 16lb cap. I bought this before I knew anything about these "steam vents" and such on the LS1 engine.

Right underneath the cap, at the top of the water neck, is a NPT fitting.

I also plan to plumb up my heater core since I will be driving this car in cold weather.

Can anyone help me? What do I need to do so I don't build air pockets in my engine?

I never knew these LS1's could make everything so complicated!

 

X2 Johnathan. I am completely confused too.

Does the thermostat during heat up on an LS motor stop the cool water from coming IN to the pump from the bottom of the radiator? Normally thermostats stop the hot water from coming OUT of the pump and into the top of the radiator.

 

Sorry, Mark and Jonathan - I can't answer your questions, but I wanted to follow up with what I settled on for a design. My system is plumbed like #3 above but as Mike JTR suggested, I've removed the line from the steam line to the radiator. I am using a pressurized surge tank.

So far, the car runs nice and cool when idling (and being rev'd) for an extended period. It would climb up to 190 gradually at which point the electric fan would come on which would bring it right back down to below 180, then it would cycle again.

I'm going to run it under load on the track for the first time in 2 weeks. I'll report back then.

Good luck, guys.

BTW - everyone who has looked at my engine and plumbing who "knows LSx engines" has had a slightly different opinion. This IS complicated for some reason!

 

Quick update - I finally ran the car on the track. We did 5 session of between 20-25 minutes under load. The water temp never got above 180, so I'm *assuming* that this routing/plumbing is working reasonably well.

Cheers,

Dean

 

not to hijack this thread but i may have missed this in the previous posts. when refering to the "steam vents" are we talking about the steel outlet under the throttle body? im guessing so since the steam vents from the heads tee and a short hose connects these to the throttle body. then on the passenger underside of the throttle body this circuit comes out.

i have this "circuit" closed off with a cap on an ls1 converted fd rx7. it cools fine but im wondering if it would be beneficial to connect this to an unused outlet i have on the top tank of this cars radiator. or do i need to re think the cooling system and include a tank as what you guys are talking about here?

 

If I understand what you're saying, you still have the steam outlets from the heads come to a Tee, then that Tee connects to the throttle body, then you have the other side of the throttle body plugged. Correct?

I'm no expert, but I think the answer to your question is yes, there would be cooling benefit to rerouting the hose that goes from the Tee to the throttle body to the top of the radiator tank. As I understand it:

a) You only need to route the steam through the bottom of the throttle body to help warm the throttle body to meet some emission standards.

b) Having the steam vents routed back in to the cooling system will help get air out of the system and make the cooling system more efficient.

So, if you're having no cooling issues whatsoever with the system as it is, you're *probably* ok. Others may weigh in here and say that you're getting local hotspots that the temp gauge isn't picking up or something to that effect - I just don't know. However, if your cooling performance is just marginal, I bet rerouting those steam vents would help quite a bit.

Good luck,

Dean

 

Its been many years since I started this thread and I am finally done with my cooling system and I can report it works very well. I have the hoses routed similar to how they are routed in a C5/C6 corvette. the items I used include

BMW E30 reservoir tank
BMW E30 Coolant cap (1.4 bar or 20 psi cap)
C5 Z06 Radiator
F-Body Coolant fans.

 

Great thread, and thanks for following up with your post. I have been eyeballing the C5 Corvette radiator wondering if the F-body fans would fit on the back... I guess they do!

Is the E30 coolant tank the one you have pictured in your last post with pictures?

Also, what coolant tank is that in "pic 3" on your first post? It looks like the C5 tank only flatter, and with one T'd port.

 

You are welcome. Yes the F-body fans will fit right onto the C5 radiator.

Yes the tank pictured is one out of an E30. I believe 1989.

The tank in pic number 3 is one out of a C5 vette, number 2 is out of a C6, number 1 is out of a mercedes.

here is a pic of my current setup

 

Another "reporting back" comment, here. I originally had the steam vent plumbed back into my surge tank. That surge tank was plumbed in to a T in the lower (inlet) hose to the engine. This was allowing the water coming out of the steam line to pass back in to the engine without going through the radiator. I recently changed the routing so that the steam line routes to the top of the radiator, and the car seems to cool better.

Just an FYI.

Cheers,

Dean

 

thanks for the update.
Mine is going on strong as well. I have been very impressed with the cooling system at keep the LS1 nice a cool (even though its not much of a task with the winter here)

 

I'm confused. So, you only had two lines from the Expansion tank - one from the bottom of the tank going to the lower radiator hose and the other from below the cap going to the overflow tank?

Then the engine steam vent going to the radiator directly.

I'm just not tracking. Trying to install one myself and want to make sure I get it right.

Thx.