Unpossible. The paths will cross. The joys of the boosted GM life. Corvettes suffer similarly, but have larger openings.

 

Gah.

Well, at the least I will be making a larger air dam. Just debating if I want to seal the air dam to radiator duct area.

 

I'm thinking feed intercooler from front, rad/AC from bottom, and direct intercooler discharge to rad/AC.

 

So don't try to isolate the air dam to radiator path? Allow the intercooler air to comingle?

 

For that you'd want to dump the ic air behind the dam, but the rad/AC air comes from in front of the dam. IMO what I suggested is going to be your best compromise.

 

So in case improved ducting does not show coolant temp drops, what other options are there?

Thoughts are perhaps a larger/thicker new core, but I think that will just take longer to reach temps and reach same peaks.
Pull existing EWP out, and either send back for rebuild, or throw money away on a new one. (prob 10 years old at this point)
Go crazy and run dual pumps, also throwing money away

 

Why do you want temps lower? 195-220 is perfect.

 

Colder motor gives me more forgiveness with knocking, still living the dream of running boost on pump 93 with no meth.

 

You can still do that, just not with any sort of timing.

 

Usually when you have higher temps at highway speed than at idle, you have a coolant flow issue (too slow). But being our cars are bottom breathers you can check to see if the air flow is an issue by commanding the fans to come on regardless of vehicle speed. By about 45mph the air flow through the radiator should exceed what the fans can do, so if turning the fans on at highway speed improves your coolant temps, you have an air flow issue and looking into improving the air dam will be effective. But, if the fans running make no difference (even a little difference would be noticed if the air flow is poor) then look into a coolant flow issue.

You've already said flushing the engine helped, but it looks like your ambient temps also dropped so that could be moot. It could be your thermostat or your water pump is going out. At 50°f your engine should be riding the thermostat (if a 160° thermostat then the temps should basically be no higher than 165° ish). One thing to remember is that, depending on your highway rpm, EWP tend to run hotter at highway speeds than lower speeds (due to their lower GPM vs a mechanical pump at more than about 2K rpm) while mechanical pumps run hotter at lower speeds and cooler on the highway for the same reason.

180° coolant temps isn't anything to worry about IMO, but if it were my car I'd want the coolant temps riding the thermostat at highway speeds if it's only 50°f ambient. For comparison, it was 109°f ambient here today and my coolant temps only got to about 185° with the AC on at 50 mph (no fans).

I would try the fans on at highway speeds and see if that helps, if not replace the thermostat, and if still no improvement replace the EWP. If the fans do help with temps, modify the air dam/shrouding.

 

Its a new thermostat (had hoped to have the cheapest option fix it) but I am concerned about a old EWP potentially losing its steam from brush wear etc.

 

After just installing a $130 3 core all aluminium Chinese radiator purchased off ebay, I can assure you the stock LT1 radiator is a POS and marginal at best for a healthy stroker (383) driven in heavy stop and go traffic in the south where it's regularly 90+ degrees and humid AF. Not to mention the plastic tanks get brittle with age and eventually crack on you and risk blowing out all your coolant and damaging your engine.

I've had this car since 1997 with stock radiator and it would always stark getting bad heat soak when you beat on it in the summer time especially; and then with 383 came a 160 stat, Meziere HD electric WP, fan tuning by PCM for less... which works well enough when it's below 70 degrees outside and you aren't stuck in traffic. Added bonus, it looks pretty and shiny under the hood, no unsightly, fugly plastic tanks, also the aluminum tanks hold a higher capacity of coolant, core is 2"+ thick, 3 cores vs 1. Now highest it will go (75% water/ 25% coolant + bottle of water wetter) is 185-190, that is with the low speed fans on after extended idling. Haven't yet heard the high speed ones engage because it's just too cool!

I was barely able to squeeze it in with the stock fan shroud; which needed some slight further modification with the dremel tool around where the long *** Meziere WP sticks out.

Downside; the low coolant sensor won't fit without leaks, even tried bigger O-rings; so just eliminated it with the plug; I check my temps regularly anyhow and the coolant level, I don't need the idiot light anymore which often comes on for no reason anyway. Not to mention I've had issues with that sensor leaking on my old LS1 car

Long story short; save your money on expensive waterpumps and just put in a ebay radiator. I got mine from Speed Daddy

Additional 3rd party source confirming there's major gains to be had by upgrading the weenie little LT1 radiator (without spending $679 for a USA made product) http://www.superchevy.com/how-to/070...vy-camaro-z28/

 

That's cool and all, but a proper shroud is night and day regardless of radiator.

 

That maybe so, but a "proper shroud" doesn't do **** when the plastic tank pops and coolant gets expelled everywhere at an intersection leaving you stranded. Nice hefty tow bill and blown heads gaskets as a result (still remember that vividly from 20+ years ago! haha) ; keep that POS plastic junk thank you! If you are keeping one of these cars "forever" invest in a real all metal radiator, not the made by Fisher-price plastic junk.

 

Got a link to that radiator you used?

I have always subscribed to the thought that a larger radiator just prolongs the time it takes to heat up, but won't lower that final temp.

 

So you're calling the plastic radiator junk, while advocating for a "real metal" Chinesium unit. Gotta love the logic train here.

 

That's true if the total cooling capacity is still less than needed to maintain the coolant temp desired. A larger radiator will always increase cooling capability. The best method for a larger radiator is a larger cross sectional area of air to coolant heat exchange (making the core wider or taller or both). But in our cars, that limit is reached at the stock size. Adding a 2nd core does still help though. Increasing the radiator size does two things, it increases system capacity and it slows the coolant down in the radiator without slowing it down in the engine.

Heat transfer is the fastest when the temperatures of the air and the coolant have the highest delta. The hotter the coolant and/or the cooler the air the faster the heat energy will transfer from the hot coolant to the cooler air. The hotter your engine gets, the faster the radiator can cool it back down. Making the radiator bigger means there's more coolant to heat up, but it's only in the block for the same amount of time, and more time for the temperature delta at the radiator to equalize. That means cooler coolant being returned to the engine from the radiator and the engine still having the exact same amount of time to heat that cooler coolant back up. If the cooling capacity of the radiator and fans is sufficient for the coolant temps your targeting then it will maintain those temperatures. But if it's not, it'll just take longer for the higher than desired temperature to happen.

I hope I explained this so that it makes sense.

 

*more time in radiator, not slower flow.

I will look at what the largest 2 or 3 pass radiator I can cram in my already over full cooling stack.

 

Yeah, that's more accurate.

 

As an update, dropped two degrees of timing out at cruise conditions, from 38* to 36*

Installed a thicker all aluminum core radiator.

Ambient temp was about a 100* today and ect climbed to 220

Hit F it and bought a new ewp