Still overheating - Chevelle Tech
Heating & Cooling Heating, cooling and air conditioning

 27Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 32 (permalink) Old Jul 4th, 20, 5:33 PM Thread Starter
Tech Team
 
Join Date: Nov 2016
Posts: 83
Still overheating

Need some help/recommendations please:

What I have and added so far:

1. 1970 Chevelle, rebuilt 454 big block stroked out to 496, about a year old. Isky racing cam, long tube headers, Holley 4 barrel carb (750 cfm), Edelbrock intake manifold, new temp sensors and gauges (and moved sensor location a couple times to ensure it's not on air bubble), no A/C or heater.

2. After starting car and driving, temp goes thru 190 to ~ 200 and then after a few moments, temp drops below 190 (guessing that it cools down because rad fans come on at 185). Then temp starts creeping up no matter if driving fast, slow or idling to 230 and if I allow it, past it to 235 and up.

3. Installed new Griffin aluminum radiator (Summit # GRI-6-00006) 2 row, dual 17" electric fans, 1734 cfm each, core width = 28". After installation, have drained it, refilled, scoped it out to see if any blockages, put dye in to try to detect whether head gasket blown (nothing detected). Large rad hoses have been replaced with new ones. New overflow container, correct rad cap.

4. Experimented with taking thermostat completely out and with different restrictor plates. Ended up with one restrictor plate.

5. 7 quart oil pan. Installed an oil cooler with electric fan on radiator part. Changed oil.

6. Upgraded alternator to 150 amp.

7. Tried several different timing settings but ended up with 55 degrees BTDC.

8. And some other stuff can't think of at the moment.

Any other suggestions? Am I doomed? Can this be fixed, I mean, is there a possibility that I will never get this thing to stay at a reasonable temperature?

Thanks for any response/help.

Baffled Ben.

1970 Chevelle SS (clone)
454 cid (496 stroker)
Holley 4 bbl 750 cfm
Muncie M21 (Hurst shifter)
Long tube headers
Tuxedo Black - black interior
chevyhawaii is offline  
Sponsored Links
Advertisement
 
post #2 of 32 (permalink) Old Jul 4th, 20, 10:31 PM
Lifetime Premium Member
leo
 
Join Date: Oct 2003
Location: Southwest Florida
Posts: 13,519
Re: Still overheating

Vacuum advance hooked up to manifold vacuum?, what is your base timing??
chevyhawaii likes this.

Leo Paugh
Maryland Chevelle Club #017
A.C.E.S.#3731
progress has little to do with speed, but lots to do with direction

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
LeoP is offline  
post #3 of 32 (permalink) Old Jul 4th, 20, 11:15 PM Thread Starter
Tech Team
 
Join Date: Nov 2016
Posts: 83
Re: Still overheating

Yes on vacuum. Base timing is 18.

1970 Chevelle SS (clone)
454 cid (496 stroker)
Holley 4 bbl 750 cfm
Muncie M21 (Hurst shifter)
Long tube headers
Tuxedo Black - black interior
chevyhawaii is offline  
 
post #4 of 32 (permalink) Old Jul 4th, 20, 11:22 PM
Lifetime Premium Member
 
Join Date: Oct 2005
Location: CT,USA
Posts: 13,430
Re: Still overheating

Three questions for you:

#1. What intake manifold are you using?

#2. And does your manifold have a weird divider plate casted into the thermostat port floor like the one I just removed from mine shown in the pics below?

#3. Are you using this small 3/4" or 5/8" diameter bypass hose like the factory BBC engines came with, also shown in the pics below?
Attached Thumbnails
Click image for larger version

Name:	1970-chevelle heater hoses II.jpg
Views:	18
Size:	143.0 KB
ID:	632058   Click image for larger version

Name:	Thermostat wall II.jpg
Views:	18
Size:	54.1 KB
ID:	632062   Click image for larger version

Name:	Thermostat wall VIII.jpg
Views:	14
Size:	57.3 KB
ID:	632064   Click image for larger version

Name:	100_4158.jpg
Views:	16
Size:	68.9 KB
ID:	632066  

Attached Images
 
chevyhawaii likes this.

70 Chevelle SS clone (632 CI powered).
BillyGman is offline  
post #5 of 32 (permalink) Old Jul 5th, 20, 4:06 AM
Lifetime Premium Member
Al
 
Join Date: Apr 2011
Location: SO CAL...Huntington Beach and Rancho Cucamonga
Posts: 5,745
Garage
Re: Still overheating

https://www.chevelles.com/forums/32-...erheating.html This is his thread where we went over this last year. Maybe some of you other guys can see something I missed.

Install a bypass hose or hook up your heater.

Pull the heads and check what type of block and gaskets you are running. Parallel flow vs series flow.

Did you change out the water pump?

Do you have anything mounted in front of the radiator like a condenser or trans cooler? If so removing or relocating those would help your cooling. Electric fans are weak sauce when putting up against resistance through thick radiators, condensers, and trans coolers.

Somethings not right as that radiator and shroud set up should cool that engine with no issues.
Attached Thumbnails
Click image for larger version

Name:	engine passenger side view.jpg
Views:	25
Size:	111.0 KB
ID:	632072   Click image for larger version

Name:	Engine driver's side view.jpg
Views:	26
Size:	109.3 KB
ID:	632074  
chevyhawaii likes this.
DUTCH MAX HEADWORK is offline  
post #6 of 32 (permalink) Old Jul 5th, 20, 5:27 PM Thread Starter
Tech Team
 
Join Date: Nov 2016
Posts: 83
Re: Still overheating

Thanks for your response. It's an Edelbrok intake manifold. Haven't noticed that divider plate but will look closer next time. I have not done the bypass hose but I thought that it was more for helping with starting not necessarily for helping cooling once it got to operating temp.

1970 Chevelle SS (clone)
454 cid (496 stroker)
Holley 4 bbl 750 cfm
Muncie M21 (Hurst shifter)
Long tube headers
Tuxedo Black - black interior
chevyhawaii is offline  
post #7 of 32 (permalink) Old Jul 5th, 20, 5:43 PM Thread Starter
Tech Team
 
Join Date: Nov 2016
Posts: 83
Re: Still overheating

Yes, same thread, sorry for reposting, thought I'd try to put all the improvements in one place.

Understand about the bybass hose, but as I mentioned in earlier response, I thought that was more for helping with starting, I'll revisit the idea.

And, yes, pulling heads is next on the list, was hoping to find something before we got to that point.

I asked about rehooking up heater and response here was that it wouldn't help.

Put in new upgraded water pump, forgot to add that to the list of things we have done.

The only thing we've added to the front of the radiator is the radiator/fan for system to cool the oil. It covers a small area and I don't think that's it because it was overheating before we added it.

1970 Chevelle SS (clone)
454 cid (496 stroker)
Holley 4 bbl 750 cfm
Muncie M21 (Hurst shifter)
Long tube headers
Tuxedo Black - black interior
chevyhawaii is offline  
post #8 of 32 (permalink) Old Jul 5th, 20, 7:40 PM
Senior Tech Team
Greg.
 
Join Date: Apr 2011
Location: Ottawa, On, Canada
Posts: 5,513
Garage
Re: Still overheating

Quote:
Originally Posted by DUTCH MAX HEADWORK View Post
https://www.chevelles.com/forums/32-...erheating.html This is his thread where we went over this last year. Maybe some of you other guys can see something I missed.

Install a bypass hose or hook up your heater.

Pull the heads and check what type of block and gaskets you are running. Parallel flow vs series flow.

Did you change out the water pump?

Do you have anything mounted in front of the radiator like a condenser or trans cooler? If so removing or relocating those would help your cooling. Electric fans are weak sauce when putting up against resistance through thick radiators, condensers, and trans coolers.

Somethings not right as that radiator and shroud set up should cool that engine with no issues.

Did not see your Response to the above Question Max asked you

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirk's67SS is offline  
post #9 of 32 (permalink) Old Jul 5th, 20, 7:57 PM
Lifetime Premium Member
Al
 
Join Date: Apr 2011
Location: SO CAL...Huntington Beach and Rancho Cucamonga
Posts: 5,745
Garage
Re: Still overheating

Before you pull the heads, try to get a bypass hose or heater hooked up. The heater will act as a bypass as long as you don't install a shutoff valve. The downside to this is you'll bring heated coolant into the cabin which you probably don't need in Hawaii. It may raise your interior temps.

I've seen the lack of bypass hose cause problems for some guys with big blocks. I know of many that don't run one and have no issues. I can't explain it, but it happens. This is your next easiest, least invasive step.

That radiator and shroud should have no problems cooling that engine once you get over about 40mph even without the fans running.

Can you post a picture of what's going on in front of the radiator so I can clear this thought from my mind?

If you post a picture or info of the casting code and date code, I might be able to tell you if that block has the potential for having a cooling problem related to parallel or series flow cooling. Of course, a picture of the block surface and gasket used would be better. If the wrong gaskets were used, there's no cure you can throw at it without correcting the gasket.
Kirk's67SS likes this.
DUTCH MAX HEADWORK is offline  
post #10 of 32 (permalink) Old Jul 5th, 20, 7:58 PM
Senior Tech Team
Greg.
 
Join Date: Apr 2011
Location: Ottawa, On, Canada
Posts: 5,513
Garage
Re: Still overheating

First I am not a Fan of Metal Shrouds as I stated in the other Thread you had
as they Tend to Heat up & Hold in the Heat at the Rad

You have a 70 Chevelle which means that it's Size of Rad Core is almost Double of the little Rad in mine
that keeps my car at 180* with SPAL Dual 11" Efans / plastic/fibre Shroud
and I only have a small Trans Cooler down Low away from the Front of the Rad core







And like Max said Efans will not Pull Air easily thru multiple layers of Cores of A/C Condenser/Rad Core etc.

It looks like you might have Room for a Mech Fan and Stock Type plastic/fibre Shroud
which would be better for pulling Air thru those multi cores of A/C Condenser & Rad Core

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirk's67SS is offline  
post #11 of 32 (permalink) Old Jul 6th, 20, 12:43 AM Thread Starter
Tech Team
 
Join Date: Nov 2016
Posts: 83
Re: Still overheating

Here's pic of newly installed oil cooler. It's to the right (facing car) of the hood latch. I realize that it is blocking the rad somewhat but it was overheating before this was installed. I could relocate it of course, just don't think it will help.
Attached Thumbnails
Click image for larger version

Name:	oil cooler.jpg
Views:	55
Size:	110.6 KB
ID:	632162  

1970 Chevelle SS (clone)
454 cid (496 stroker)
Holley 4 bbl 750 cfm
Muncie M21 (Hurst shifter)
Long tube headers
Tuxedo Black - black interior
chevyhawaii is offline  
post #12 of 32 (permalink) Old Jul 6th, 20, 5:03 AM
Lifetime Premium Member
 
Join Date: May 2004
Posts: 2,159
Garage
Re: Still overheating

First thing I would try is add the bypass hose, intake to water pump, as seen in BillyGman post. I see you do not have one. It is cheap to try...


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.
Life is not a journey to the grave with the intention of arriving safely in a pretty and well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out and loudly proclaiming: "WOW! WHAT A RIDE!!"
Redmanf1 is offline  
post #13 of 32 (permalink) Old Jul 6th, 20, 1:45 PM
Senior Tech Team
Greg.
 
Join Date: Apr 2011
Location: Ottawa, On, Canada
Posts: 5,513
Garage
Re: Still overheating

Quote:
Originally Posted by chevyhawaii View Post
Here's pic of newly installed oil cooler. It's to the right (facing car) of the hood latch. I realize that it is blocking the rad somewhat but it was overheating before this was installed. I could relocate it of course, just don't think it will help.

So the Engine was Over Heating before the Oil Cooler was installed


You put more Air Flow Restriction for the Efans and it did not Lower the Engines Running Temp


Do not know why you would put a Oil Cooler on a Street/Strip Car
they are usually used by Cars running around in Circles an a Paved Track
when the Engine is Running at High RPMs for Long Periods/Hours of Time

What else do you have in Front of the Rad Core ?

Please get so more Pics of the Front of the Rad Core
and some more of the Engine Side

Does the Shroud cover all of the Rad Core ??

I see you have a 4 Bolt Top Plate so that Rad with a 28" Wide Rad Core
should keep that Engine running at 180* to 195* IMHO


Unless the Timing is not Right or there are Water Cooling Passages partially Blocked

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirk's67SS is offline  
post #14 of 32 (permalink) Old Jul 6th, 20, 8:44 PM Thread Starter
Tech Team
 
Join Date: Nov 2016
Posts: 83
Re: Still overheating

Oil cooler one was one of our last ditch attempts to try and cool it down. We're kinding of trying anything at this point. After install, discovered that it didn't make a difference...but I have slightly cooler oil now, for whatever that's worth.

We're desperate.

1970 Chevelle SS (clone)
454 cid (496 stroker)
Holley 4 bbl 750 cfm
Muncie M21 (Hurst shifter)
Long tube headers
Tuxedo Black - black interior
chevyhawaii is offline  
post #15 of 32 (permalink) Old Jul 6th, 20, 9:09 PM
Senior Tech Team
Greg.
 
Join Date: Apr 2011
Location: Ottawa, On, Canada
Posts: 5,513
Garage
Re: Still overheating

So Cooler Oil means it is Thicker than Warm Oil !

So how new are the Rad Hoses ?

If your Rad Core is 28" Wide how does the two 17" Efans / Total of at lest 34"
fit across it properly
is the Shroud properly Sealed to the Edges of the Rad Core where it is welded to the End Tanks ??

See the third Pic in my Post # 10 of how my car's Shroud covers all the Rad Core
and is Sealed properly on the Side and Top Edges where the Fins are Welded


And again Metal Shrouds tend to Heat Up and keep more Heat at the Rad Core
thus the Coolant in the Rad not Cooling down enough to keep your Engine Running Cooler

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirk's67SS 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










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