461 stroker won't stay cool at idle

[Poncho461]

As the subject states, my 461 stroker won't stay cool at idle.  Brand new engine/radiator everything. I'm running Evans waterless coolant. The Engine was completely drained before added the new coolant. All hoses, heater core and radiator were brand new upon adding the coolant. Water pump is an aftermarket Flowkooler. I had a 180° thermostat in it and switched out in favor of a 160°. It didn't help. The engine has seen temps of 214° before shutting it down because it would just keep climbing. As soon as you hit the road the car will dive down to 170 to 180° no problem. This is just an idle issue. Any suggestions? Thanks!

[b_hill_86]

What kind of cooling fan/shroud setup  are you using? If it cools off when you start moving it sounds like lack of airflow across the radiator at idle.

Also, what’s your initial timing set at and are you running a vacuum advance can? If so, ported or manifold?

[81Blackbird]

What is the condition of the fan clutch? Could be something as simple as a replacement or up grading to a HD clutch.

[nUcLeArEnVoY]

Summer means overheating threads, lol.

First step - verify your temps. Are you really at 214? Infrared thermometer or mechanical temp gauge help confirm this.

If your temps are accurate, then solving idle overheating is usually pretty easy. If you cool down at speed, then you just have insufficient airflow at idle. Are you using an electric fan, or a factory shroud and clutch? If the former, then electric fans are iffy on these cars - the ONLY one I've heard nothing but good reviews about is the Flex-A-Lite #295 dual 13.5" fans. Outputs 4600 CFM at full blast, but puts a hell of a draw on the alternator so you'll need to upgrade your alternator. That is the only e-fan I've heard of that actually cycles on and off like a modern car and will reportedly suck an empty beer can out of your hand. It also happens to seal and fit *PERFECTLY* on a second-gen radiator.

But if you're still using a stock shroud and fan clutch, your fan clutch may just need replacing. Don't even bother "testing" it. Just replace it, maybe with a Hayden HD version (part #2747). And I certainly hope you are using a shroud. Shrouds exist for proper airflow at idle.

And then finally as mentioned, ignition timing. A 461 stroker, I'm guessing you have a fat camshaft... all the more reason to throw in a ton of timing at idle. This can be accomplished with a vacuum advance hooked to manifold vacuum, as b_hill mentioned, since obviously putting the initial really high will cause starter kickback. A factory '79 W72 had around 36-37 degrees of total timing at idle with vacuum advance hooked up, since the vac advance received metered manifold vacuum through a calibrated modulator valve. If you're not running vacuum advance, then your ignition timing is probably way too low for proper idle cooling. High timing = cool idle, and it's not a problem as far as detonation is concerned because there is no load on the engine during idle, and the moment the throttle plates open up wide, vacuum advance is gone, anyway.

Try those things and see how it works out for you.

[tajoe]

I think all bases have been covered. Investigate, decide, correct, and be rewarded.
(By the way. You didn't mention if this was a re-occurring problem, or just cropped up)

[Poncho461]

Current set up has a set of 12 inch electric fans on it. I think I may have a combination of problems which may lead to a couple more posts on here. The build has maybe 20 to 30 miles on it and has not ran very well the entire time. I've been chasing problems with a new holley sniper set up and I believe timing is playing a large part of why it's not cooling at idle. Only verification of coolant temps is what the sniper data logs showed me via touchscreen and laptop. Have not actually verified with a temp gun. Car makes 600hp and the is 242/248 duration at .050 with a 112 lsa and right around 609/619 lift with 1.65 rockers so my initial guess is timing. What does everyone recommend for timing at idle?

[Oldsschool79]

You mentioned the electric cooling fans, did you verify the proper direction of air flow? I have seen fans wired in reverse causing the fans to turn opposite direction.

[Poncho461]

Yes we verified the fans moving in the right direction. Fairly certain this is going to be a timing issue more than anything but haven't had time to work on it. Holley has a generic setting of 15° at idle. Which I'm sure is far less than I need.

[ryeguy2006a]

Can you please post a picture of your timing curve? Are you using the 2D or 3D tables for timing?

[nUcLeArEnVoY]

Yes we verified the fans moving in the right direction. Fairly certain this is going to be a timing issue more than anything but haven't had time to work on it. Holley has a generic setting of 15° at idle. Which I'm sure is far less than I need.

15 degrees may actually be good since you're probably making a lot more static compression. What's more important is that you hook up vacuum advance (or use the vacuum advance "simulation" function that a lot of the EFI systems incorporate) off of manifold vacuum, to give you extra timing at idle that won't interfere with cranking. If you bump your initial up too much, then you'll end up wrecking your starter.

[scarebird]

Very lean mixture will heat up fast too.

[BBATCAR]

Current set up has a set of 12 inch electric fans on it. I think I may have a combination of problems which may lead to a couple more posts on here. The build has maybe 20 to 30 miles on it and has not ran very well the entire time. I've been chasing problems with a new holley sniper set up and I believe timing is playing a large part of why it's not cooling at idle. Only verification of coolant temps is what the sniper data logs showed me via touchscreen and laptop. Have not actually verified with a temp gun. Car makes 600hp and the is 242/248 duration at .050 with a 112 lsa and right around 609/619 lift with 1.65 rockers so my initial guess is timing. What does everyone recommend for timing at idle?

Just for reference, I have a similar set up - 462 Stroker, roller cam and rockers, KRE heads, Griffin Radiator with dual fans about 500HP. I also have an Edlebrock high flow water pump which I like better than a standard pump. I was having heat problems with my Holley EFI. I took the EFI off and put on a carb back on, that was the only change (along with timing). My car now runs about 190* or less.  If I run it HARD, it will only get to 205*/210* then it will cool down to 190*once I stop jumping on it.

It feels to me to be something with the EFI running lean or fans not kicking on. My fans are hooked up to my Dakota Digital dash and both my fans are on HIGH once it hits 180* and pretty much run all the time. That will make a big difference if your Holly EFI is not set up that way. Without my fans, my car will heat up fast but with the fans on full, my car runs a cool 180*-190* range consistently. Just something to check.

[djustice]

Current set up has a set of 12 inch electric fans on it. I think I may have a combination of problems which may lead to a couple more posts on here. The build has maybe 20 to 30 miles on it and has not ran very well the entire time. I've been chasing problems with a new holley sniper set up and I believe timing is playing a large part of why it's not cooling at idle. Only verification of coolant temps is what the sniper data logs showed me via touchscreen and laptop. Have not actually verified with a temp gun. Car makes 600hp and the is 242/248 duration at .050 with a 112 lsa and right around 609/619 lift with 1.65 rockers so my initial guess is timing. What does everyone recommend for timing at idle?

First thing i would do is confirm correct temprature, i have had a sniper on my car since 2019, and the temp sensor that came with the sniper was bad out of the box (pretty common) , mine was a few degrees of when cold, but deviated more as the temprature increased.

A good thing to check on the handheld is IAT and CTS temp, when cold this should be about the same with maybe a 1-2 degrees difference, a dead giveaway is when these 2 temp readings do not match up when the car is cold , (been parked for more than 12 hours).

A common "upgrade" is standard motorproducts TX3 CTS sensor, that is what i got and it is very accurate.

[Poncho461]

Went through everything and I what I came up with is the 12 inch dual fans are not flowing enough air for my combination. Time to upgrade to some nice spal fans! Thanks to everyone that gave me suggestions!

[nUcLeArEnVoY]

Went through everything and I what I came up with is the 12 inch dual fans are not flowing enough air for my combination. Time to upgrade to some nice spal fans! Thanks to everyone that gave me suggestions!

Even better than the SPAL fans are the ones I recommended, the Flex-A-Lite #295. They're 13.5" dual e-fans that output 4600 CFM, have conical shrouds for each fan, and the entire assembly happens to fit perfectly over most 2nd-gen radiators, though they're meant for trucks. You need a strong alt and a controller to run them at full tilt, but most people that have used them say they will suck a beer can out of your hand when they turn on, and that they're the only e-fans that Poncho 400 owners have ever used that actually cycle on and off. Like SPAL fans, they incorporate flaps into the shroud assembly that are forced open by ram air at highway speeds to further aid in heat dissipation.

[djustice]

I just did the same thing last year, i had 2x 12" no-name chinese fans rated 80 watts, in a shroud on a champion 2 row alu radiator.
It almost was enough, but on hot days (For Norway), temp above 70 F  it really struggeld to keep temps in check.
I got 2x 12" Spal fans. And man what a difference. i bench tested my old fans vs the new spal fans, the old one would blow pretty good, but when i hooked up the spal fan it took off and flew straigth into the wall lol!
And there was a size difference even though they where both rated 12" i had to clerance the shroud more with tin snips , not pretty but hidden by the fans.

had to up my Fuse size 15Amps mostly for inrush current on start up. Fan NR.2 has never even kicked in yet.