stock 69 overheating
Thread Starter
Racer
Joined: Jan 2004
Posts: 463
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From: South Haven MI
Re: stock 69 overheating (jacobsed)
Was there a plastic and metal stock style factory shroud? Docrebuild.com has the combinations: brass with plastic shroud and aluminum with metal shroud.
Thread Starter
Racer
Joined: Jan 2004
Posts: 463
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From: South Haven MI
Re: stock 69 overheating (sb69coupe)
Thanks for posting the pics. Anything closeup available? Mine is also a stock L46. Who knows why the shrouding is different. I can buy the correct fan clutch and fan at autozone for around $35 a piece. I was going to buy the rubber gaskets for the "radiator to support" and "shroud to radiator" but it looks like I'll need to get the correct shroud also. I just need to verify if the plastic one is correct for the L46. Or maybe the correct fan clutch and fan would do the trick??
Team Owner
Joined: Aug 1999
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SPARTAN
CI 3-4-5-6-8-9-10 Vet
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Re: stock 69 overheating (jacobsed)
Your fan should look like this one:
Unless you had A/C in which case it should look the same except with 7 blades instead of 5.
Your fan clutch should look like this:
The factory clutch is a thermal clutch. A viscous clutch should work ok, too.
The tough part will be finding the right fan. For whatever reason, the corvette fan diameter is slightly smaller than most other GM products. I can't recall the diameter off the top of my head though.
Unless you had A/C in which case it should look the same except with 7 blades instead of 5.
Your fan clutch should look like this:
The factory clutch is a thermal clutch. A viscous clutch should work ok, too.
The tough part will be finding the right fan. For whatever reason, the corvette fan diameter is slightly smaller than most other GM products. I can't recall the diameter off the top of my head though.
Melting Slicks
Joined: Mar 1999
Posts: 2,845
Likes: 2
From: Apex NC
Re: stock 69 overheating (jacobsed)
In my opinion, you have a shroud for a base radiator, which was an 18" aluminum core. It was very common to replace these radiators with the copper/brass radiators when they failed, since the aluminum radiators were much more expensive than the copper/brass units.
Here's my estimation of what happened with your car. It looks as though a previous owner replaced the radiator and just bolted up the old shroud and hoped for the best. He then noticed the same cooling issues that you are experiencing. Rather than troubleshoot the problem correctly by looking at the last thing that was changed (the radiator, and most importantly, the shroud) they decided "well, the fan clutch must be bad too, let's put on a direct drive flex fan". It may have helped a bit, but the problem still persists.
Here's what I'd do. First, measure the width of your radiator core. Determine whether it is a 26" or 27" core unit. Then purchase the correct shroud and seals for the radiator, along with a stock fan clutch and fan. Install everything as stock and I'll give you 10 to 1 odds that your overheating problem at idle will be solved.
Shannon
Here's my estimation of what happened with your car. It looks as though a previous owner replaced the radiator and just bolted up the old shroud and hoped for the best. He then noticed the same cooling issues that you are experiencing. Rather than troubleshoot the problem correctly by looking at the last thing that was changed (the radiator, and most importantly, the shroud) they decided "well, the fan clutch must be bad too, let's put on a direct drive flex fan". It may have helped a bit, but the problem still persists.
Here's what I'd do. First, measure the width of your radiator core. Determine whether it is a 26" or 27" core unit. Then purchase the correct shroud and seals for the radiator, along with a stock fan clutch and fan. Install everything as stock and I'll give you 10 to 1 odds that your overheating problem at idle will be solved.
Shannon
Le Mans Master
Joined: Jan 2001
Posts: 6,938
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From: San Diego CA
Re: stock 69 overheating (ddecart)
The cars cooling system runs great but in the intrest of returning the car to stock what am I looking at price range for fan and clutch?
[Modified by Cali,68,L-79, 8:01 AM 3/2/2004]
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
Re: stock 69 overheating (Cali,68,L-79)
Cali, those fans are notorious for shedding blade bits at high rpm. Lose it, bud. My '69 with air was also missing the 7 blade fan. I cut down and re-balanced a mid '80's Mopar 7 blade aluminum fan, then used a stock fan clutch with excellent results on all but the hottest days (100 plus) with the A/C on. I have the full width 27" plastic shroud with seals all around. It's cut at the bottom to allow installation without removing the radiator.
Hans
Hans
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Safety Car
Joined: Jan 2001
Posts: 3,637
Likes: 27
From: Norwalk Ct
Re: stock 69 overheating (jacobsed)
Check the heater core aswell.
My buddy had the engine in his 68 recently rebuilt, car was fine whilst driving , soon as it started to idle it would overheat.
Turned out the new "high flow" waterpump did a good job of stuffing a lot crud into the heater core and effectivley blocked it.
Just something you may want to check.
Nick
My buddy had the engine in his 68 recently rebuilt, car was fine whilst driving , soon as it started to idle it would overheat.
Turned out the new "high flow" waterpump did a good job of stuffing a lot crud into the heater core and effectivley blocked it.
Just something you may want to check.
Nick
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: stock 69 overheating (jacobsed)
Att his point just spring for an elec fan, all the stuff you need to update what you got will run almost as much a a decent elec fan, this will also free up a few ponies to play with.
Thread Starter
Racer
Joined: Jan 2004
Posts: 463
Likes: 0
From: South Haven MI
Re: stock 69 overheating (sb69coupe)
Did GM put base radiators in L46 optioned cars? My car is numbers matching and very original all around. It would be very surprising to me anything wasn't.
Race Director
Joined: Oct 2002
Posts: 12,065
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From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
Re: stock 69 overheating (jacobsed)
I was having the same problem with my 77. Tried putting a cooler thermostat to no avail. Finally changed out the clutch and now it's almost running too cool! Need to change back to a warmer stat now....
Melting Slicks
Joined: Oct 2002
Posts: 3,255
Likes: 0
From: Manalapan FL
Re: stock 69 overheating (Fevre)
Att his point just spring for an elec fan, all the stuff you need to update what you got will run almost as much a a decent elec fan, this will also free up a few ponies to play with.
Just did the elec. thing. Car runs cool, engine compartment looks a lot cleaner and I'll probably get $1000.00 for the old set-up on E-Bay.
D. Ocean
Miami, FLA
