LS1/LS6 steam vents??

[paul_3rdgen]

I have an 01 LS1 that I modded to use the LS6 valley cover so I am using the LS6 steam tube configuration, front cross tube and the two rear ports are blocked.  After reading a few times that it is better to have all four connected I bought an LS1 steam tube setup(doesn't fit ) I also have the Kurt urban blocks  http://www.kurturbanperformance.com/water-line-adapters.html  so i could build my own steam line setup.   

After fooling around with this for a while I was wondering if it would be OK to just join the two rear ones together without looping them into the rest of the system?  I want to do things right but i just can't stand clutter under the hood so I want to keep it simple but effective....what are my options?

[zbrown]

Why not mod the intake to clear the 4 port setup?

Many have here,  not much work and I think it is a definite good thing

[southside427]

ive got two ls6 tubes im going to put on each end and tie in with a  "T" fitting,heard thats a good setup for removing all the air out of the systym

[largeorangefont]

Why not mod the intake to clear the 4 port setup?

Many have here,  not much work and I think it is a definite good thing

It is not only that, the Ls1 steam "spider" hits the PCV connection on the LS6 valley cover so you need to mod the spider as well as the intake.

I have the same problem and read that the Grand Am guys use the Ls6 front corssover and the blockoffs in the back so that is what I'm gonna do.

If anyone wants to sell their rear blockoffs and LS6 crossover tube let me know. I have an LS1 spider if anyone wants it.

[paul_3rdgen]

I tried to modify the intake so it would work...no deal.  LargeOrange is right the PCV connection from the valley cover is the bigger problem. 

[dp.drift]

Would either of these setups work? If you already have the ls6 couldn't you use one of these?



Hope that helps.

[dp.drift]

Another option would be to cut the ends off with about 1.5 inches of pipe. Getting the same diameter and some snake bite fitting you should be able to get it to work anyway you want it.

[Jordan Innovations]

Long story short ~ Pratt & Miller (http://prattmiller.com/) and Dr. Jamie Meyer (head of GM Performance) both say that the rear two should stay blocked off.

I used to advocate having fittings that went to -4an on all 4 steam vents feeding into a coolant swirl pot, which then drained back into the lower hose or return heater line... this is a setup that was used successfully by a few race teams, but it looks like this was a band-aid once I got 'real' information from REAL race teams.

The issue is not flow - the coolant passages flow plenty - it's pressure.  When driven hard, engines need coolant pressure to "scrape" the steam bubbles that form on hot spots in the head off the wall of the passage.  With all 4 ports open, there's not enough pressure locally (in the head) to promote proper heat transfer unless you run your overall coolant pressure extremely high (30psi or so).  Indy and F1 cars run MUCH higher than that, due to higher hp/liter (heat concentration).

The proper setup all my LSx racers are using is, assuming the top of your radiator is below the steam vent port:
*The rear vents blocked off, the front tee'd (LS6-style).
*Radiator cap replaced with "open" cap (free flow through radiator overflow port)
*Steam vent tee and radiator "overflow"/free flow feeding into coolant swirl pot (aka expansion tank)
*Swirl pot has pressurized radiator cap, bottom drains to non-thermostat-controlled water pump return

Conrad Grunewald's LS7, fully built by GM Performance/Brian Thompson (ignore Conrad's goofy smile, this was a 3am "we just got it running right" moment)


Matt Powers' LS7, same setup (just harder to see lol)

[paul_3rdgen]

What your describing is what I've been running for the last 4 years, if your right I will just leave it alone and I just wasted countless hours and $150...

[zbrown]

Long story short ~ Pratt & Miller (http://prattmiller.com/) and Dr. Jamie Meyer (head of GM Performance) both say that the rear two should stay blocked off.

I used to advocate having fittings that went to -4an on all 4 steam vents feeding into a coolant swirl pot, which then drained back into the lower hose or return heater line... this is a setup that was used successfully by a few race teams, but it looks like this was a band-aid once I got 'real' information from REAL race teams.

The issue is not flow - the coolant passages flow plenty - it's pressure.  When driven hard, engines need coolant pressure to "scrape" the steam bubbles that form on hot spots in the head off the wall of the passage.  With all 4 ports open, there's not enough pressure locally (in the head) to promote proper heat transfer unless you run your overall coolant pressure extremely high (30psi or so).  Indy and F1 cars run MUCH higher than that, due to higher hp/liter (heat concentration).

The proper setup all my LSx racers are using is, assuming the top of your radiator is below the steam vent port:
*The rear vents blocked off, the front tee'd (LS6-style).
*Radiator cap replaced with "open" cap (free flow through radiator overflow port)
*Steam vent tee and radiator "overflow"/free flow feeding into coolant swirl pot (aka expansion tank)
*Swirl pot has pressurized radiator cap, bottom drains to non-thermostat-controlled water pump return

Conrad Grunewald's LS7, fully built by GM Performance/Brian Thompson (ignore Conrad's goofy smile, this was a 3am "we just got it running right" moment)


Matt Powers' LS7, same setup (just harder to see lol)

Are you saying running a 4 port setup in that configuration degrades cooling?

Because if so I will take my chances

[Jordan Innovations]

Yes Zach, that's what GM Performance and the guys that have dominated Le Mans with the C5R and C6R have said.  Like I mentioned above, coolant pressure is what's required to effectively transfer heat from the heads to the coolant, and insufficient coolant pressure is a common reason for popped head gaskets (hot spots develop).

When I asked about the teams successfully racing with all 4 ports opened up, they asked what power levels they were at, and if they were N/A or boosted - at 400-500hp, it's not an issue, but Conrad's old setup was 700hp or so and supercharged - even at 11.5-12:1 AFR's, we popped the gaskets twice on cold days.  On street cars, they chuckled and mentioned 1500hp turbo cars with stock radiators, meaning anything can be reliable on the street for a short time.

[zbrown]

well i don't have any problems whatsoever

with the new radiator setup, surgetank, and crossover i cool like a champ, even with a the puny 35gpm pump you say won't cool anything

first vid is of the amount of coolant discharged from the crossover into the surge tank

second is to show coolant temp.... i had made atleast 5 back to back runs on the highway there since i was logging last weekend while increasing the boost more and more...... was going to make a vid, but it was to hard to keep track of stuff when it got into boost so it was a fail..... need a gopro camera


if it cools my car it is going to cool a head/cams street car no problem

[Jordan Innovations]

Data logging with the Iphone, love it. 

I think you're missing the point about coolant pressure.  The overall coolant temp is an average temp, but it's by no means a measurement of the hotter parts of the engine (even measured in the head, like LSx's).  The point that the real race guys were trying to get across to us was that when you don't have the pressure within the head to move the small bubblets around, that's when hot spots start occurring. 

Highway passes can certainly show the weaknesses in some systems, but comparing those pulls to road-racing (even autocross) would be apples/oranges. 

[southside427]

well theres some reason that alot of guys are now wanting the ls1 style crossovers and installing them on their ls6 manifolds and setups,whether it be misinformation or the latest fad i dont know,ive heard of problems with air pockets causing problems in some of the back cylinders,mainly #7 i believe,this is something i def. want to avoid

[zbrown]

Ha no I had the hpt running for logging..... I just grabbed the camera since I was so impressed with the power increase but as you can see I gave up on making a good one

Data logging with the Iphone, love it. 

I think you're missing the point about coolant pressure.  The overall coolant temp is an average temp, but it's by no means a measurement of the hotter parts of the engine (even measured in the head, like LSx's).  The point that the real race guys were trying to get across to us was that when you don't have the pressure within the head to move the small bubblets around, that's when hot spots start occurring. 

Highway passes can certainly show the weaknesses in some systems, but comparing those pulls to road-racing (even autocross) would be apples/oranges.