It's Summer - Nuts must be overheating !!!!

[Don Jacks]

Nuts,I've had my best and least expensive results on a 78 MALIBU with a "WARM"355 by using 'factory"electric fans.The one I think would be best for you could possibly be from 94-96 full size Caprice.These things were enginered for cars with a/c,smog controls,ect.They're eaiser to get replacement parts for,and just seem to work better.I had 2 large aftermarket fans on it eariler and just took forever to cool back down between rounds,and ran hotter than I wanted.The factory fan set-up solved this.Another alternative might be an aux.electric water pump in the lower rad hose,wired in with the a/c for use at low speeds[and faster cool down between rounds for the times when you play "boy racer"]

 

[32witha409]

So the question for today is: "how to get the air flow of the electric fan at idle, without creating the air dam ?

Blow back panels is your answer. The corners of the shroud block ram air flow so add panels like I showed in the post above.

While idling the panels are drawn so the shroud by the electric fan and force the fan to draw only through the radiator. While on the highway the ram air flow is greater than the fan can draw so there is some ram air pressure that blows the thin rubber panels back releasing the blockage to ram air flow. If it works on hotrod it'll work on anything.

 

[JimKwiatkowski]

Bill, we have almost the same size radiators. There both Griffin, with two 1 1/4" tubes, the core is almost the same size, mine is a crossflow and yours is a downflow, both cool the same. Yesterday I drove the 57 20 miles, in stop and go driving at 25,35 & 45 mph speed zones. The temperature was 78 deg, the 57 ran no higher 160 deg. I'm not saying you will get these good results with a 5 1/4" pulley, but you should drop at least 10 deg, because the pulley increases fan speed and coolant flow is what you need. Maybe then you can add a small fan for idle.

 

[oldskydog]

In support of Jim's pulley size theory, GM used the same idea to solve idle cooling problems on 66 427 Corvettes.:


1966: Engineering Service Letter: Overheating at Idle
Subject: Overheating at Idle
Model and Year: 1966 Corvettes Equipped with 427 - 390 HP (RPO L36) with Factory Air Conditioning (RPO
C60)
Source: Service Update - Chevrolet Engineering Service Letter
Number: TNP #66-1
Date: November 16, 1965
Overheating at Idle - 1966 Corvette with L-36 and C-60
Overheating may be experienced in the field on early production 1966 Corvettes equipped with the L-36
engine and air conditioning. Complaints of this nature may be due to the use of a 5.90" diameter water pump
and fan pulley. Replace the 5.90 diameter pulledy with a 5.39 diameter water pump and fan pully, and then
change belts as necessary.
In addition to the pulley substitution, the top of the radiator support should be checked to determine if the
radiator support seal has been installed. Some early production Corvettes were built without this seal. If no
seal is present, one should be installed. The effective production date for both the pulley and seal will be
supplied when available.
© Copyright General Motors Corporation. All Rights Reserved

 

[jdk971]

look at photo in post 56. dewitt put rubber flaps at all four corners. these flaps will
open when driving at speed to keep a air damn from happening. best of luck jim

ps i would try the pulley and use a mechanical fan setup as mentioned above.

 

[Mr.1961]

Lots of good thoughts and thanks to all for taking the time to post them !!!!

The "Good News" I'm back to running the temp I was before the latest electric fan fiasco ! The "Bad News", I'm back to running the temps before the electric fan ! The problem is indeed, an air dam, blocking the ram air flow at all speeds. While the temp stayed "reasonable" (200*) even in traffic, with the A/C running, it never dropped below that either. At highway speeds, it was even worse (200-230) !!!

So I removed the fan and shroud to see if that was the problem or something else had changed ? I put the six blade flex fan and shoud back on. The temps dropped over 50 degrees on the highway and in general dropped 40 degrees around town in light traffic. Instead of running 200-210 degrees in general driving, she will cool down (170-180) as soon as I get moving down the road. The electric fan and shoud was blocking air not only at highway speeds, but also under city driving conditions.

So the question for today is: "how to get the air flow of the electric fan at idle, without creating the air dam ?

The electric fan would hold temps at 200 while at idle, but if you were moving, it wouldn't allow the air flow to cool it down, even at low speeds. I can cool her down with the current set up, with one exception, "idle !" I don't have enough room for an electric fan addition in front of the mechanical.

May be the answer is an un-shrouded electric fan ? After this weekend's show-n-shines, I'll try that ? I still have a little money left, I think !!!! There is a big show next weekend, that includes a parade down town. I've never been able to complete the cruise, and I'd sure like to just once !!!!

Bill,

If you have no further use of the Black Magic Extreme puller fan, please let me know I'll will purchase it from you. I live by these fans.

 

[Nuts]

Sorry All - I was not ignoring you, but I've been off to the 40th Annual Porcupine race and show ! If you've never watched porcupine races, you have not lived your life to the fullest ! Admittedly, this was our first time also, what a hoot !!!! Anyway it was a 300 mile round trip and Ms Bella drove like a dream. On the way back it was in the 80’s and she stayed 170-175* with the A/C running,at two lane and freeway speeds.

Still need to fix the temps at idle, but I’ll be working on that today. I’m going to install the electric fan inside the current shroud, which should allow plenty of air flow, without creating an air dam. I know I could put flaps on the Black Magic set up, put that won’t help the fact that she ran hotter at slow speeds and the flaps won’t help there ? Not sure why the pulley from Summit has not come in, but I'll follow up on that tomorrow, still plan to change that out.

Well, off to work on the next chapter in this story. I’ll post and update when I get her done and checked out.

Bill,

If you have no further use of the Black Magic Extreme puller fan, please let me know I'll will purchase it from you. I live by these fans.

Seth - I'll keep that in mind, for now I've just added it to the stack of fans, shroud, clutches and other attempts at cooling.

Bill

 

[mike bell]

Nuts- I've been watching this thread, as you know I have the same problem. Saturday I went to a cruise about 15 miles from home-180-190 on the highway-200-210 in town and when I had to stop for traffic, I was almost afraid to look at the guage!!!!!!! I a new alum. radiatorfrom auto city classics(since my car is a '58 my choice of radiators is quite limited, unless I want to pay750 on up for a one off radiator from BE Cool.) I hope the w/p pully does the trick for you. Since you've been elected my "ginny pig" on this; I'm waiting to see the outcome before I spend the money!!! I guess I'm gettin' tight or I'm afraid to ask Diana for the check book!!! I guess an electric fan would help me but I tried to keep the stock look as much as I can! Hurry up, do some work and publish your results and if things look favorable, I'll come up with a story why I need the checkbook.
Tell Linda we both said "Hi" and we're looking foward to next time. Thanks Mike

 

[petepedlar]

as you know I have the same problem

Ggeeeeze.......... do all of us Old Fools have Hot 409's?????

I read and enjoyed the article that Cecil posted about the Corvette's........ Thanks Cecil. I have been busy with other things since I got back from Thompson, but I have a plan to follow tha suggestions in that article. The info about the fan clutch was interesting...... the new ones not doing anything until a higher temp is reached. I was told some time ago about the air going through the rad, getting hot and then circulating back over the top of the rad........ if you look at my engine compartment it's quite obvious that's happening.......... it's pretty tight in there & where is all that air coming through the rad supposed to go ????????
I found a NOS fan clutch on Ebay some time ago. It is the one without the temperature coil on the front. I bought some air dams for the front to stop the hot air circulating back over the rad........... With the big electric fan it's livable but I just don't like the sound....... the over all plan:
- back to the big 7 blade mechanical fan
- the NOS fan clutch...... hopefully it will start to work at a lower temp than the new one
- air dams
- Jim K's smaller pulley


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=350316125459&ssPageName=STRK:MEWNX:IT


I'll keep you informed.
Dave

 

[Clyde Waldo]

Hay Dave - as one of the oldest of the old fools I can say that I never had an over heating problem with my 1962 409/409 Impala that I drove from early 1962 til mid 1965. What I mean is that it never boiled over - who knows what the actual temperature was what with the silly green light/red light idiot light set up.

When I put that engine in the 1955 T-Bird I used the stock T-Bird radiator (factory issue for the Ford 292 cu in) and used the stock T-Bird fan shroud with the stock 409 thermal fan set up. Back then I participated in the St Louis St Pats day parade for several years & would do fast idle in neutral sometime while sitting & waiting for parade to move forward.

The 409 truck engine now in the T-Bird made it to Thompson & back home to Missouri with out boiling over (my definition of not over heating ). The T-Bird temperature gauge is operating on 12 volts (1955 Fords were 6 volt positive ground) so indicates high but still better than idiot lights. I am using stock 409 pulleys, a 180 degree thermostat, and run the radiator cap not all the way tight to go easy on the hoses & 55 year old radiator. I may not have an ideal setup but seems to work for me.

Clyde

 

[JimKwiatkowski]

Dave, I would let Bill try the pulley first, before you buy one. Club member Chevytaylor from Australia, says an Australian GM Holden car, uses a 5" pulley that will work, but I can't find any place in US that sells Holden parts

 

[oldskydog]

Guys,
I'm no expert and I know this has pretty much been covered in all the discussions of overheating, but here is a general guide in checklist form which may be useful for those who are, or will be, experiencing these problems.

1. Instrumentation.
Check your hose and neck temps with an IR gun to confirm you guage/sender is correct. The sending units today are notoriously inaccurate.

2. Timing.
Make sure it's not retarded and the curve is correct.
Check your vacuum advance to make sure it is correct for your engine vacuum at idle and is functioning correctly.
Make sure you are connected to full manifold vacuum for advance, not ported. Ported vacuum advance is a later emisiions systems feature and is wrong for our older engines.

3. Airflow.
Check for complete shroud. Make sure the fan is half in-half out of shroud.
Check to make sure all air must flow through the radiator. Foam pipe insulation works great to fill the gaps on the sides of the radiator.

4. Mechanical
Check your fan clutch. You shouldn't be able to spin it more than a couple revolutions when shut down hot. Thermostatic type fan clutches are best and can be adjusted by repositioning the spring.
Make sure you have the correct pressure radiator cap. A 15 psi cap raises the boiling point of water to 265 deg.
Make sure you have the correct size waterpump pulley. A smaller size pulley turns the pump faster and may help.
Be sure you have a spring in the lower radiator hose. Many aftermarket hoses don't include the spring.

5. Fluid
Make sure you are using the minimum amount of antifreeze vs water for your climate. More antifreeze=reduced cooling.

6. Fuel
Make sure you're not running lean. Lean mixture can cause detonation resulting blown head gasket as well as piston/bearing damage. Blown head gasket adds combustion gasses into the cooling system. Coolant can be tested for presence of combustion gasses.

There are probably more things to consider, but this is a start.

:

 

[JimKwiatkowski]

5 inch pulley

Here's more proof that the 5 inch pulley works.

Jim. I couldn't find a number on the pulley. They are pretty thin on the ground over here, now only found in wreaking yards etc. They are 5 1/4" in diameter and either shallow or deep offset. To the best of my knowledge the shallow offset pulleys were on Holden red six cyl engines from 1963-1980. The deep offset (longer water pump bearing) were on Holden blue six cyl engines from 80-84. I run a single groove deep offset in the photo. Searching through my mates wreaking yard last week, I found BB1960 a 5 1/4" deep offset tripple groove and a 7 blade clutch fan.
I don't have any overheating issues. Will idle between 170-185 and highway cruise between 175-195 depending on outside air temps. Have seen 200 a couple of times but only in extremely hot weather conditions.

 

[mike bell]

Dave Years ago when I started this project and said that I wanted to build a"HOT 409", this isn't exactly what I meant!!!!!! I'll let my ginny pig (NUTS) do all the work and hopefully I can reap the benifits. If he keeps pluging away, maybe we'll get this all figured out! I hope to work on the car this weekend and maybe I can find something that I missed.Mike

 

[Nuts]

Here's more proof that the 5 inch pulley works.

hey are 5 1/4" in diameter and either shallow or deep offset.

Jim, the current pulley I have is 5 1/4 in. OD. Is that the same size as the one you are recommending ???

I'll let my ginny pig (NUTS) do all the work and hopefully I can reap the benifits. Mike

Mike,

I can pig with the best of them, but I'm not sure I'm the guy I'd recommend to run alot of tests !!! As you know I've been "ginny piggen" on this problem for 5 years now and haven't made ANY progress !!!! :eek:

Bill

 

[JimKwiatkowski]

Bill, yes I'm running a 5 1/4" OD.

Bill here's a Quote you wrote 4 years ago.

Jim,

I measured the pump pulley again this morning and she is 6" outside and a little smaller where the belt runs. I didn't think to measure the crank pulley so I'll have the check that this evening. Memory tells me it's a little bigger than the pump but the tape will tell.
__________________

 

[Nuts]

Bill, yes I'm running a 5 1/4" OD.

Bill here's a Quote you wrote 4 years ago.

Jim,

I measured the pump pulley again this morning and she is 6" outside and a little smaller where the belt runs. I didn't think to measure the crank pulley so I'll have the check that this evening. Memory tells me it's a little bigger than the pump but the tape will tell.
__________________

Jim,

You are correct, I wrote that. But if you remember, when I was going to pull the 409 out and put the 327 back in and your said: "Before you do all that, take 5 min and change the pulley ???" Well I put on the stock pulley off the 327 and removed the aluminum one. That got me about 30 degrees cooler on the average and running 170-180 on the highway.

Only complaint I've had since is at idle.

Thanks for staying with me on this for 4 years plus. Most, would have given up and told me to go straight to "$!@@".

Bill

 

[petepedlar]

Thanks for staying with me on this for 4 years plus. Most, would have given up and told me to go straight to "$!@@".

....... wouldn't help Bill........ it's hot there as well.


Dave

 

[Nuts]

So the latest update !! I installed the other electric fan, without the shroud, so there would be no air flow issues. DID NOT WORK !!! She still got hotter than with the mechanical Flex fan ????

So the short story is, she doesn't like electric fan ? I'll put her back to standard and drive her and put up with the heat at idle until something else comes along. Shoot, there is still money to be spent on cross flow radiators, water pumps, pullies and dual fans. Butt for now I'm putting this to rest.

I can still put the 327 back in !!!!!

Bill

 

[Mr.1961]

So the latest update !! I installed the other electric fan, without the shroud, so there would be no air flow issues. DID NOT WORK !!! She still got hotter than with the mechanical Flex fan ????

So the short story is, she doesn't like electric fan ? I'll put her back to standard and drive her and put up with the heat at idle until something else comes along. Shoot, there is still money to be spent on cross flow radiators, water pumps, pullies and dual fans. Butt for now I'm putting this to rest.

I can still put the 327 back in !!!!!

Bill

Bill, is the model you're using happen to be the #185 Extreme Puller 3,300 CFM?

I'll take it off your hands, if you're ready. I'm thinking of trashing my new flex-a-lite water pump driven fan for another Black Magic Extreme. As said before, I live by these fans. I'll have to purchase a new US radiator 4 row desert cooler as well. I want to cool down Old Gold she's running a bit hot, and she's puked twice when I've parked. I think that is me to blame on the coolant mix though.