Need Help w Overheating 327 '66 - Chevelle Tech
Heating & Cooling Heating, cooling and air conditioning Sponsored by:Cold-Case Aluminum Radiators

 12Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 66 (permalink) Old May 2nd, 18, 8:32 AM Thread Starter
Lifetime Premium Member
 
Join Date: Nov 2017
Location: Sioux Falls, SD
Posts: 159
Garage
Need Help w Overheating 327 '66

My recently rescued '66 that has been sitting in a barn for 20 years is coming along nicely. However, I'm having a problem with overheating. I can't run it for more than 10 minutes and it starts banging, clanging, and hoses will pulse. The coolant has been flushed several times after I pulled a lot of crap out of the motor, including a renegade lock washer. It currently has a bottle of Blue Devil coolant flush in it that will get drained tonight after a couple of days of running. I have no temperature gauge on the dash but my infrared shows normal readings everywhere. Except the top of the block, where after 10 minutes it starts getting hot.

I need your help.

What do I try next? Radiator? Water pump? Pull the engine apart?

1966 Malibu 327 200-4r
brockmub is offline  
Sponsored Links
Advertisement
 
post #2 of 66 (permalink) Old May 2nd, 18, 9:40 AM
Tech Team
Rick
 
Join Date: May 2017
Location: Bossier City, Louisiana
Posts: 802
Re: Need Help w Overheating 327 '66

Any recent work on the top of the engine? Gasket change?

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

1970 El Camino under Reconstruction - 5.3L LS VORTEC Engine and 4L60E Transmission
B52bombardier1 is online now  
post #3 of 66 (permalink) Old May 2nd, 18, 9:48 AM
Senior Tech Team
Ed
 
Join Date: Aug 2013
Location: Pittsburgh, PA
Posts: 4,269
Garage
Re: Need Help w Overheating 327 '66

First thing, is it circulating coolant through the rad? I'd pull the thermostat and run without a cap keeping the rad full as it warms up. If it is boiling in the block, and flowing through the rad, something must be blocked somewhere.
I looked back at your thread and that picture of the crud in the intake looks funky. Maybe flush/fill/clean many times.

1967 El Camino Malibu - Deepwater Blue
ZZ4 350, FiTech 600 complete!,Roadmaster tank, 700R4, Underdash A/C in progress, JGC Steering, 1990s truck serpentine.
Pioneer4x4 is offline  
 
post #4 of 66 (permalink) Old May 2nd, 18, 10:58 AM Thread Starter
Lifetime Premium Member
 
Join Date: Nov 2017
Location: Sioux Falls, SD
Posts: 159
Garage
Re: Need Help w Overheating 327 '66

Quote:
Originally Posted by B52bombardier1 View Post
Any recent work on the top of the engine? Gasket change?
I did not open up the engine other than to replace the valve cover, carb, and thermostat gaskets. Should also mention that I replaced the thermostat and radiator cap. Placed the overflow tube into a large plastic bottle so it stops puking all over my floor.

Yes the crud was horrible inside the intake initially. Now that I've run it a while it's perfectly clean, so I know that fluid is moving past that point.



Heater hoses get hot with the car and the heater in the car could fry an egg. So water is moving through there. Which points me back to a blocked passage in the block some where. I really don't want to pull the motor apart yet. I'll keep flushing with water and maybe some additional additives.

1966 Malibu 327 200-4r
brockmub is offline  
post #5 of 66 (permalink) Old May 2nd, 18, 11:30 AM
Senior Tech Team
jeff
 
Join Date: Jan 2008
Location: yukon ok.
Posts: 4,985
Re: Need Help w Overheating 327 '66

How old is the radiator?
I had a rebuilt radiator in my delta 88.. kept the 350 olds cool.
Stuck that radiator into my 78 Nova and my .060" over 350 ran hot 210 F..I tried all kinds of fans and thermostats and coolants and shrouds.
That rebuilt radiator began leaking on a tank top..I decided to get a NEW radiator they were 94 bucks.

Guess what.. she ran 140 F I had to remove the 2 electric pushers and stick on a shallow pitch fan to get it to 160.

I do not even mess with "rebuilt" radiators any more .

You must have some of the fan blades on the outside of the shroud..as you probably know.
That is if you run a shroud.

If it is sitting idle for 10 minutes this may also be the issue.. get it on the road.
Some cars need air pushing on the radiator.. maybe a fan in front of it.

In all honesty though my stuff can sit all day idling without getting past 195.
Knock on wood.
jeff swisher is offline  
post #6 of 66 (permalink) Old May 2nd, 18, 12:26 PM
Lifetime Premium Member
John
 
Join Date: Feb 2000
Location: MN, USA
Posts: 896
Re: Need Help w Overheating 327 '66

Drill an 1/8 hole in the thermostat. It will allow any air trapped under the thermostat to bleed out.

John

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Instructions...All I need is the exploded view.
Enganeer is offline  
post #7 of 66 (permalink) Old May 2nd, 18, 12:45 PM Thread Starter
Lifetime Premium Member
 
Join Date: Nov 2017
Location: Sioux Falls, SD
Posts: 159
Garage
Re: Need Help w Overheating 327 '66

Quote:
Originally Posted by Enganeer View Post
Drill an 1/8 hole in the thermostat. It will allow any air trapped under the thermostat to bleed out.
Thanks for the reminder about that tip. I had heard it before and then forgotten it. It's a good thing that the thermostat gaskets are a buck because I've gone through a ton of them.

Tonight I'll drain the water and Blue Devil, then drilling a little hole in the thermostat. Might also see what other additives are out there to hopefully find the blocked passage.

1966 Malibu 327 200-4r
brockmub is offline  
post #8 of 66 (permalink) Old May 2nd, 18, 1:35 PM
Lifetime Premium Member
Bill
 
Join Date: May 2016
Location: Near Kansas City, Missouri
Posts: 51
Re: Need Help w Overheating 327 '66

Remove the block drain plugs on each side of the block and flush with water. I tried attaching a photo of these plugs, but it would not upload.

Bill
Billrv7 is offline  
post #9 of 66 (permalink) Old May 2nd, 18, 1:40 PM
Lifetime Premium Member
Jeff
 
Join Date: Mar 2006
Location: Southwest
Posts: 1,290
Re: Need Help w Overheating 327 '66

Find an old bottle of DuPont radiator HD radiator cleaner that used caustic soda. Nasty stuff but will clean all that scum and scale. I would use the old radiator for the flush cycles and once all clean, drop in a new radiator, maybe even run a screen in the upper hose to catch debris before it would plug up a new radiator. I believe the DuPont had a small neutralizer agent that came as a separate compartment in the can.

Jeff

64 El Camino Pro street, 496, T-400, 9" 3.73


Video:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
fr8dog is offline  
post #10 of 66 (permalink) Old May 2nd, 18, 8:56 PM
Senior Tech Team
Jim
 
Join Date: Oct 1999
Location: Fresno
Posts: 1,862
Re: Need Help w Overheating 327 '66

Look at that picture...what do you suppose the inside of the cooling tubes in the radiator look like. As has been mentioned, don't waste your time with an old radiator. You cannot effectively "flush" a radiator at home. For a hundred bucks or so, you can have new one. Drill a hole in the thermostat? Is there something that the engine and thermostat designers and engineers don't know? No thermostat that I know of will make an airtight or watertight seal with the thermostat housing anyway.
JJ'65 is offline  
post #11 of 66 (permalink) Old May 2nd, 18, 11:41 PM
Senior Tech Team
Justin
 
Join Date: Dec 2016
Location: Huntington Beach
Posts: 1,213
Garage
Pop out the drain plugs on the side, remove the hose to the top of the radiator and plug your house into the bottom water pump Inlet. Fire up the engine and turn on the hose and flush that bad boy out. Water will gush out of that thing and clean it it out, might have to bring up the rpm to get it really flowing

1974 chevelle with 73 laguna nose sbc 357 Brodix IK180 heads Comp Cams XE274H Edelbrock RPM airgap 650 AED double pumper, M20 muncie, Truetrac with 3.73s
JF74chevelle is offline  
post #12 of 66 (permalink) Old May 3rd, 18, 9:23 AM
Super Mod
Rich
 
Join Date: Oct 1999
Location: Waverly, NE USA
Posts: 15,685
Garage
Re: Need Help w Overheating 327 '66

Quote:
Originally Posted by brockmub View Post
I can't run it for more than 10 minutes and it starts banging, clanging, and hoses will pulse.
Quote:
Originally Posted by brockmub View Post


These are all the evidence you need to signify you need to pull the engine apart. You have probably already damaged it. Put in a new radiator before you run it again.

NCOA member #220
ACES member #1670
Team Chevelle #998

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Rich Cummings
Rich-L79 is offline  
post #13 of 66 (permalink) Old May 3rd, 18, 12:28 PM Thread Starter
Lifetime Premium Member
 
Join Date: Nov 2017
Location: Sioux Falls, SD
Posts: 159
Garage
Re: Need Help w Overheating 327 '66

If I didn't trust a 50 year old gas tank, why would I trust a 50 year old radiator? That is a legitimate concern. It is a little bit lower on the priority list but a definite possibility to the eventual solution. I actually thought that I was going to need to replace the radiator because the brass drain plug on the bottom was all messed up. It severely mangled and being brass it was easy to make even worse. So I gave up trying to make it drain and just pulled it.



The new brass drain plug will go in tonight and the Chevelle will go up on the ramps to see if I can get access to the rear drain plugs. I'll try another round of water and flush additive.

The thermostat is going to come out before I drill a hole. Two mechanic friends gave conflicting advice about drilling. Though they both agreed that the symptoms the car is having do not seem like air is trapped but more like it could be a blockage.

1966 Malibu 327 200-4r
brockmub is offline  
post #14 of 66 (permalink) Old May 8th, 18, 11:36 PM Thread Starter
Lifetime Premium Member
 
Join Date: Nov 2017
Location: Sioux Falls, SD
Posts: 159
Garage
Re: Need Help w Overheating 327 '66

Replaced the brass plug for easier draining, actually popping the bottom hose into a bucket is pretty easy and quick. Flushed two more times, but it's still overheating after about 6 minutes of idle time. When it drains, I analyze the bottom of the bucket as I pour it into a container for transport. There are some flecks of corrosion but nothing big or like I've pictured previously. The past two flushes have been with water, Blue Devil, and no thermostat. I've opened the cap while its still cold and observed the water flowing past the opening and no obvious bubbling like maybe a bad head gasket would show.

Called Champion today and purchased a AE289 2 Row - 1" tube aluminum radiator. It was cheaper directly from them instead of Eckler's or Jeg's. I've heard a mixed bag of reviews on them but thought it was the next least invasive step to getting the car on the road. Saturday we should have it and hopefully it fits as well as takes care of the problem.

AE289

Once I know the radiator fits and is functioning, I'm debating if I should cut up the old original to see if there are in fact blockages. Any thoughts if I should cut up the old radiator?

1966 Malibu 327 200-4r
brockmub is offline  
post #15 of 66 (permalink) Old May 9th, 18, 12:33 AM
Senior Tech Team
 
Join Date: Dec 2004
Location: tucson az
Posts: 14,097
Send a message via AIM to Jim Mac
Re: Need Help w Overheating 327 '66

don't forget to buy a anode for your new aluminum radiator and add a ground wire from the rad to the core support. I know the water is a ground etc, but some of these rats come with a wire in the box and it only takes a minute. jim

Jim

70 chevelle, SS clone 454 4 speed
71 camaro. (owned since 1978!) 6-71 blown small block 400
66 chevelle 350 4 speed 3.55 12 bolt
66 el camino 350 th350 parts hauler
Jim Mac is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Old Thread Warning
This Thread is more than 614 days old. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
If you still feel it is necessary to make a new reply, you can still do so though.

Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome