Author Topic: Running hot (Read 3912 times)

Stangman · « **on:** June 05, 2021, 05:49:16 PM »

Ok first off sorry not FE but helping a neighbor.
68 Camero 540 ci 9.0 to 1 compression (690) HP on motor.
F2 procharger with intercooler low in front of radiator.
Tranny cooler high in front of radiator but both are about 6 inches away.

He has had this set up for a while. He just freshened up motor and the only difference is an electric water pump. (Highest flow pump JEGS make) and he was told by Miezer and Ron Davis not to run a thermostat.

So now the problem is he can let it idle forever and never go over about 192-95 degrees.
If he goes on the parkway the temp creeps up slowly may take 5 miles or so but it goes to 220 then he can get off parkway and cruise around town and temp goes back down to 195. So I know some of the guys use an electric pump I was wondering do you use a thermostat. You would think cruising it would run cooler. A little help please so I can advise this Chevy guy.

475fetoploader · « **Reply #1 on:** June 05, 2021, 06:20:09 PM »

I ran a moroso electric water pump on a big block Chevrolet. I ran no thermostat. I custom tuned how fast the water circulated through the engine with some inexpensive moroso coolant restrictors that take the place of the thermostat. It’s possible to pump water through so fast that heat doesn’t scavenge properly. Both in the block, and the radiator. It sounds like his heat occurs more during driving. I’m curious about air/fuel ratio, and timing. Part load, cruising speed maybe something is unhappy that causes heat. Not enough timing, too much timing, a lean condition in an intermediate circuit etc. Also I have experienced an electric fan working good on a car not moving, that becomes a restriction at 50mph. Hopefully the fan turns the correct direction, I’ve also seen that before. Especially on refrigerated shipping containers, really causes problems when the evap fans go backwards.

Stangman · « **Reply #2 on:** June 05, 2021, 07:22:33 PM »

Thanks 475 all those things are good points and I asked him all those questions. He did have the car tuned by the same guy that normally tunes it. He’s running a Holley sniper system. I’m going to advise a restrictor. He showed me a few that he has. I really was interested in knowing about running a thermostat. All info welcomed

GerryP · « **Reply #3 on:** June 05, 2021, 08:32:49 PM »

Is he in a position to fit a mechanical pump and thermostat just to aid in trouble shooting? I really don't think his issue is the pump or coolant flow volume, but you'd want to rule that out in the simplest way possible.

I know the flow issue comes up but most of the time, the flow volume is too low and causes the overheat. If the flow is fast, it travels through the engine pretty fast and doesn't spend as much time dawdling around and getting really really hot and since it didn't get heat saturated, the radiator doesn't need to transfer as much heat. If the coolant runs too slow, then it can get pretty hot in the engine before the radiator extracts the heat to start over. You would need to run thermocouples around the engine and radiator to see what the deltas are.

1967 XR7 GT · « **Reply #4 on:** June 05, 2021, 08:41:12 PM »

Without a thermostat the coolant circulates to fast and doesn't stay in the radiator long enough to get cooled. Restrictions should work, it's trial and error to find the restrictor with the right size hole.

Another thing to think about is, 35mph and above, provide the air flow the radiator needs for cooling.

Dr Mabuse · « **Reply #5 on:** June 05, 2021, 09:16:22 PM »

Never, ever NEVER drive on the street without a thermostat. Never.

He has computer controlled fuel injection, and no 'stat!

Cyclone03 · « **Reply #6 on:** June 05, 2021, 10:58:29 PM »

What is he running for a fan ?

Stangman · « **Reply #7 on:** June 06, 2021, 09:21:33 AM »

He has a Ron Davis radiator and fan assembly duel pass made for his car and horsepower.

machoneman · « **Reply #8 on:** June 06, 2021, 12:38:08 PM »

We were frugal (cheap?) long ago in my drag race 427 Camaro, we simply gutted a thermostat of the spring and tower, ending up with essentially a flat plate with a hole in it. Worked fine btw but it was not a cruiser! Also, other BBC pals followed my lead in street cars but merely matched the hole size of a thermostat, with the center removed, in a flat aluminum plate. Worked for them too.

Funny, but with old style (non-cross flow) radiators it was hard to tell how fast the coolant was moving w/o a stat. But, with any cross-flow, leave the stat out and watch that coolant zoom! Yes, too fast and it doesn't have enough time to absorb engine heat. A stat or holed plate is needed.

jayb · « **Reply #9 on:** June 06, 2021, 01:59:09 PM »

I always run a thermostat with an electric water pump. I don't believe in the "too slow" or "too fast" theories of water flow through an engine, unless they are really, REALLY slow.

I think he has a basic thermodynamics problem. At idle, the engine is putting out less heat, and his electric fans and radiator can keep the coolant cool. Running down the road, the engine is putting out more heat, and the radiator/fan package is not able to keep up, so the coolant temperature is rising. Plugged radiator? Too many things in front of the radiator, blocking it? If it was all new I'd say his radiator is not big enough or the intercooler and trans cooler are blocking too much air, but if he ran the package successfully before, then something has changed...

Stangman · « **Reply #10 on:** June 06, 2021, 07:41:57 PM »

Well previously he was using a regular pump and thermostat and it was fine. Now he is using a bigger procharger with more boost but just cruising I don’t think that should matter.

Today he put a 160 thermostat in it and it was a little better. But he has fans on all the time. I told him to put a 180 in and have fans come on at 195 and go off at 180. It was 90 plus degrees today and hot so I don’t see the benefit of a 160 thermostat it will never close after it opens especially with today’s temperature so it really is nothing more than a restrictor after it opens.
Oh today it was better on the parkway and a little worse around town with the 160 thermostat. I will keep you informed.
I’m glad you chimed in Jay I know you run an electric pump

jayb · « **Reply #11 on:** June 06, 2021, 10:03:43 PM »

For sure the extra boost DOES matter, and it matters a lot. If he is running more air volume or boost going down the road, that will add a great deal to the heat. He needs a bigger radiator.

FYI my 55 gpm CVR pump cools my NA 1000 HP SOHC just fine in traffic, on the freeway, and at the race track. It's not the pump, it's the upgraded supercharger adding the heat.

Stangman · « **Reply #12 on:** June 07, 2021, 02:58:52 PM »

Just curious Jay do you have a crossflow and did you notch the frame rails and if you do have a crossflow did you get a wide enough radiator to notch both rails.

fryedaddy · « **Reply #13 on:** June 07, 2021, 10:21:21 PM »

thats how my motor was acting.it would overheat under power,but you could slow way down or idle and it would cool.my problem was it was sucking the bottom rad hose flat.but with a electric pump i dont think that could be the problem,unless it pumps more the faster you go.

jayb · « **Reply #14 on:** June 08, 2021, 09:25:32 AM »

Quote from: Stangman on June 07, 2021, 02:58:52 PM

Just curious Jay do you have a crossflow and did you notch the frame rails and if you do have a crossflow did you get a wide enough radiator to notch both rails.

Yes and yes, 31X19 radiator, 1-1/4" tubes, dual core.

Falcon67 · « **Reply #15 on:** June 08, 2021, 10:36:16 AM »

>Today he put a 160 thermostat in it and it was a little better. But he has fans on all the time. I told him to put a 180 in and have fans come on at 195 and go off at 180.

Your advice is correct. 160 is too cold, might as well not even be in there. If the fan/radiator package does not have bleed off ports then he's also going to have air stacking up in front of the radiator at cruising speeds. I run a Meziere 35 GPH pump on the 351C with a 180 t-stat and big electric fans. Works good.

Bleed off ports on a factory e-fan setup

Thumperbird · « **Reply #16 on:** June 08, 2021, 10:51:20 AM »

I don't believe in the "too slow" or "too fast" theories of water flow through an engine, unless they are really, REALLY slow.
x2

I suppose there could be some super rare and strange situations where the coolant carrying all the heat is at the center of the flow and therefore not benefiting from the temp. differential to the heat sink.

Keith Stevens · « **Reply #17 on:** June 08, 2021, 03:54:58 PM »

I doubt this will be helpful but to elaborate on the situation. I am running a stock ford 24" core in the Mustang. I decided to add air conditioning. I haven't charged the unit yet. This is factory AC. I didn't have an issue cooling, as a matter of fact the 180 EMP T-stat kept the temperature just above the first line on the temperature gauge. After the condenser was installed it changed the running temperature at least 10-15 degrees. The inboard headlamps were known for causing the engines to run at higher temperatures, especially in any stop and go traffic. I have a sneaky feeling the ACP Max Cool radiator I have here will end up on the car.

Faron · « **Reply #18 on:** June 08, 2021, 07:43:58 PM »

A Good Read https://www.stewartcomponents.com/index.php?route=information/information&information_id=11

winr1 · « **Reply #19 on:** June 08, 2021, 08:02:41 PM »

That is indeed a good read

Ricky.

Keith Stevens · « **Reply #20 on:** June 08, 2021, 08:02:56 PM »

I love the EMP-Stewart Thermostat. However, here is a free warning. If you have any oil in your coolant it will cause the seals to swell in the EMP Thermostat. It will stick partially open or fully open.

Falcon67 · « **Reply #21 on:** June 09, 2021, 08:55:01 AM »

>I don't believe in the "too slow" or "too fast" theories of water flow through an engine, unless they are really, REALLY slow.

A Griffin engineer told me to remember "Hot water = cool motor" - the working fluid needs to pick up the heat to carry it out. Also, aluminum radiators work way better with 180 up water in them. The higher the delta between the working fluid and ambient - to a point - the better the heat exchange works.

Also, 180+ engine temps significantly reduce wear and help keep the oil clean. I even stage my methanol fueled dragster at 180.

driveamerican · « **Reply #22 on:** June 10, 2021, 02:02:06 AM »

Did he verify gauge is correct. Did he burp the the system maybe air pocket?

Stangman · « **Reply #23 on:** June 11, 2021, 05:43:31 PM »

So just an update i had him put in a 180 thermostat and had him turn fans on at 195 and shut off at 180. Although he had them turning off at 185 he did the same ride and it didnt go over 204 and the temperature was 89 and extremely humid. So I think hes going in the right direction. im gonna make him have the fans go off at 180. On a non humid day I think he will be good.

blykins · « **Reply #24 on:** June 12, 2021, 07:07:04 AM »

As long as the radiator cap is sufficiently rated, 204° is not hot.

Stangman · « **Reply #25 on:** June 12, 2021, 08:52:38 AM »

So I just talked to him this morning and he told me when he put the thermostat in he drilled 4 small holes in it . I know some guys drill a hole but at some point 4 holes is a little excessive. Almost stopping the rat ate from working properly.

jayb · « **Reply #26 on:** June 12, 2021, 08:55:19 AM »

I drill four 1/8" holes in mine, when I'm using an electric pump with no provisions for a bypass. Always regulates the temperature just fine that way.

wowens · « **Reply #27 on:** June 12, 2021, 09:21:13 AM »

Quote from: jayb on June 12, 2021, 08:55:19 AM

I drill four 1/8" holes in mine, when I'm using an electric pump with no provisions for a bypass. Always regulates the temperature just fine that way.

I do the same with factory pumps. I don't like the bypass hose look. Never had a issue.

Stangman · « **Reply #28 on:** June 12, 2021, 10:57:20 AM »

Wow ok good to know

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Author Topic: Running hot (Read 3912 times)

winr1