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Discussion Starter · #1 ·
I'm having some cooling problems with my 67. When it's warm out and I am idling, the temps creep up, especially with the Vintage Air running. They'll creep up indefinitely if you let it. It has to be an airflow problem because the minute I start moving, the temps come right back down to 180-190 with the A/C off and around 190 with the A/C on...I have a 180 deg high flow thermostat. I also have a new 4 core radiator that I installed when I put the air in at the end of last summer, a new fan clutch, and 5 or 6 blade fan and original fan shroud. I'd like to solve this problem since the temps not only creep up at idle but the efficiency of the A/C at idle is lacking. I think some good electric fans might solve my problem, so I was wondering about the Windstar or Mark VIII fans. Who has installed these things on a first gen Camaro, and any tips or pictures would be appreciated. Thanks

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
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I think adding more airflow will just be a 'band-aid' fix. I think you have a different problem.

Are you sure that new fan clutch is working properly? Never expect a new product to work correctly, they are always suspect to faults.

Does your cooling system need to be flushed? Thermostat opening completely? The reason why I believe the problem lies elsewhere is because some guys here are running old 2-core radiators with a healthy small block and a clutch or small electric fan, and everything is OK.

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1969 Base Camaro
Vortec 355, Perf. RPM, Demon Carb., TH-400
All sheetmetal is NOS GM
See my NEW webpage at: http://www.geocities.com/compuboy007/
 

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Discussion Starter · #3 ·
I don't think adding more airflow will be a bandaid fix...I think I just need more airflow. If the airflow was ok, then the A/C wouldn't warm up at idle. I am sure the new fan clutch is working properly...I replaced the original fan clutch about a year and a half ago...months before the vintage air install...and the new one moves a whole lot more air than the old one did. It works fine, at least off idle...it just seems like I don't get enough airflow at idle to keep the car cool. If I take it out of drive or rev it up a little bit, it'll cool back down as there is more airflow. The thermostat is fine...I've replaced it and checked it to make sure it opened ok before installing it. Cooling system is clean.

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
</A>
 

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Justin I tend to agree with you, not enough flow throught the radiator when idling. What we have to do is figure out why. Where is your tranny cooler and AC core mounted? If they are on the front of the radiator they may be part of the problem. Are you using underdrive pullys by chance or the wrong size on the fan? Is the shroud right against the support? How far in the shroud does the fan sit? Another couple questions I have is what type of clutch is it, thermal or non-thermal? and What is your initial timing?

Start with the timing as it's one of the more common causes when all else is in check. the initial will effect the total so be careful to avoid detonation. Check both initial and total and if you can try to set the initial to around 12-16 degs. If this pumps the total over 36-38 degs there are ways to use vacuum to add to the idle timing. Let me know what you find.

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...Dennis
"The '69, the '96 & the club"
 

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I have just installed the MarkVIII fan on my 68 w/ stock radiator. I got to really try it out Sat. I have a 180* thermostat in it with 4 pencel lead size holes in it just incase it gets stuck closed. It was about 90* Sat. here and it took about 15 minites for the car to get to 160*, then it just went a little above that point and stayed. This was at an idle. I have my fan and fuel pump tied together so I am going to have to put a different thermostat w/o holes and wire my fuel pump up seperate. I think the fan works great and don't think I am going to have any problems this summer. Also I have a warmed over 383 stroker bored .060 over and 9.7cr. If it cools it, it should cool close to anything.

My .02
Shane
 

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Discussion Starter · #6 ·
Shane,

How does the MarkVIII fan fit? What did you have to modify, and how did you mount it? Is it hard to install? How much did it cost, if you don't mind me asking? Do you have any pictures?

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
</A>
 

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This is on a '68 Chevelle. I have the dual Windstar fans, with a Stewart stage 2 aluminum water pump, and Afco radiator. On the driver side in front of the radiator I have the tranny cooler and one of the Windstar fans that lines up with the cooler runs as soon as the car starts. The other one is wired to 180 deg. thermostat.

I do not have any heating problems, at iddle, bumper to bumper traffic, or whatever.

Have some pictures on my site.

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www.yannis68chevelle.com
 

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The fan fits great. I had to cut about a 1/2" off the sides of the shroud and coraspond that at the top and bottom. To mount it I used a couple brakets off an old D-Link rack mount hub and bent them over the flange on the bottem of the radiator w/ self taping screws and one screw apeice on each side of the fan through the plastic shroud. On the top I just used plumers tape w/ 2 screws on the shroud and one in the top of the radiator. Holds very secure and looks factory. I also had to make a small grove where each of the water hoses attatch to be able to put my hose clamps on. I don't have any pictures aval. I paid $149 w/ shipping for the fan from Houston Perfromance.com, I paid $25 for the starter relay from NAPA (part # ST87), nothing for the mounts or screws, $20 on wire and a switch. I had already bought a 100AMP alt. so I was ok there. Total was $194. Look on your face when this thing kicks on = priceless. So for about the same price of a Black Magic fan you can gain like 2x the cfm.

Shane
 

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jrt,

You stated, if you give it alittle more RPM's, it cools down. And, I also see you added A/C to the car.

Correct me if I'm wrong, but, could you have a(n) anti-dieseling solenoid to use as a fast idle compensator to come on and kick open the idle speed when the compressor kicks in?

Easy check for clutch fan working, in the morning when engine is first cranked up, one should hear a roar from the engine compartment.

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Everett 68/350/PG/11.90/115mph
 

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Discussion Starter · #11 ·
Thanks for all the great replies, guys.

Djd,
My AC core is mounted directly in front of the radiator and I'm using the tranny cooler that is built into the radiator. I am not using underdrive pulleys...GM stock original pieces. The shroud fits tight against the support, and the fan fits right into the shroud, just like it should. I have a thermal clutch, and the initial timing is set at 16 degrees. I have no idea what the total timing is...it's never been checked. I've played with the timing from one extreme to the other, but it didn't help the problem.

Sweems,
Sounds pretty good...I'd definitely need to upgrade my alternator to install one of these fans.

Everett,
I don't have an anit-dieseling solenoid hooked up because I don't really need one. The VA Sanden compressor produces very little drag on the engine, so it only drops about 100 RPM when the compressor kicks on. Besides, the temp creeps up even with the AC off. The clutch also works well exactly as you described.

Now, to add another variable to the pot, this problem started right after I installed a new cam in the car. Before installing the new cam, the car would never come off of 180 degrees even if you parked it in drive 6 inches from a wall and left it for an hour. After I installed the CompCams XE268 cam, the temp problems started, but I don't understand why. The cam I replaced was almost the same cam...I had no idea what cam was in the car, and the one I installed was virtually the same cam. The engine idles at the same speed it did before the cam swap. I did not pull the heads or anything when I installed the cam, so I couldn't have obstructed a coolant passage. I only pulled the intake and water pump. What do you guys think???

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
</A>
 

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Justin, Dennis is right on here with airflow across the radiator. The fact that your temps come right down as soon as you get moving is simple deduction of flow thru the radiator.

I would run vacuum advance. It can make a difference on full vacuum port. It will give you over twenty degrees at idle. The perfect timing for your engine at idle is dependent on many factors, but I can tell you with my experience here in Atlanta that all of them like at least 20.

If you added the Vintage air, the fact that you have a coil up front is somewhat of a blocking issue to the air especially at idle. If the XE cam that you changed added VE to the engine causing more fuel to be spent, even at idle, and they usually do, then this is more waste heat to rid yourself of.

You have two choices. Go for a bigger mechanical fan or crossover to an electric one. I recommend running fans on a 134 system anyway for efficiency purposes. You will see a marked difference in temperature at the vents.

Check out my cooling forum for more cooling ideas and tips. Go to www.inccn.net/techforum/htm.

I know for a fact that an aluminum crossflow radiator would do the job hands down!


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STEVE JACK
ConceptOne Pulleys and Brackets
Techical forum/links at www.inccn.net/techforum.htm
 

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Aha! You changed soimething else and didn't tell us, the cam.

I agree with Steve, you've changed the VE of the engine. Now, you must remove more heat.

A couple of suggestions here, 1) change from a thermal clutch fan to a RPM clutch fan. This will be "ON" at idle and low engine speeds; 2) change the crankshaft pulley to a larger diameter, usually 1/3 larger than the w/p pulley.

Might also think about changing the antifreeze/water ratio from 50/50 to 25/75 or 30/70 mixture. The more water, the cooler engine will run.

Everett
 

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Discussion Starter · #14 ·
Thanks guys

Steve,
I do run vacuum advance...my car is set at 16 degrees initial advance with the vacuum advance unplugged, so I should actually have over 20 degrees of advance at idle. The specs on the cam I added was hardly any different than the specs on the cam that I removed...I would hardly think that such a small difference in specs would cause such a difference in volumetric efficiency.

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
</A>
 

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Justin,

There are two places you can get vacuum for the vacuum advance ckt. One is manifold and has vacuum at idle. The other is often refered to as ported and has no vacuum at idle. If you use the manifold source you can reduce the amount of mechanical advance you run and still have higher idle advance.

At this point I'm inclined to believe the added load placed on the engine (greatest at idle) by the AC compressor and the AC core in front of the radiator core are the cause of the additional heat. To test this remove the AC belt and move the AC core out of the way. Fire the car up in the driveway and see where it goes...

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...Dennis
"The '69, the '96 & the club"
 

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Discussion Starter · #16 ·
Dennis,

I'm running the advance on full manifold vacuum. The A/C is not the problem, as the car has done this since I installed the cam 4 years ago. I just installed the A/C at the end of last summer. The initial problem is still there, the A/C just makes it worse when it is turned on. Before installing the A/C, the temps would creep up at idle in drive. If the car is at idle in neutral, the rpms are a little higher, and the temps stay steady at 180 degrees. I've been thinking it's a lack of sufficient airflow and figured the powerful Mark VIII or Windstar fans might fix the problem.

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
</A>
 

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Justin,
You might try speeding up the fan by using a smaller water pump pulley. My cousin had a 70 chevy half ton pickup that used a smaller water pump pulley.
Don't use 50%/50% mix of water/anti-freeze, use 30%/40% mix. Nothing cools as well as water.

By the way, I looked at your engine photo. You should relocate your sparkplug wires for cyls # 5&6. They are running parallel to each other from distributor to engine. while this looks nice, those two cylinders are sequential in firing order and voltage can be induced from #5 to #7 plug wire causing it to fire 90 degrees too soon.
Many engines have been damaged from this happening. Spiral core wires are a help in reducing this problem.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page
First Gen Suspension Page
67 RS 327 original owner. 69 Camaro Vintage Racer, 65 Lola T-70 Chev SB Can-Am Vintage Racer

[This message has been edited by davidpozzi (edited 05-15-2002).]

[This message has been edited by davidpozzi (edited 05-15-2002).]
 

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Discussion Starter · #18 ·
David,

Thanks for the tip about the plug wires...I'll check it out.

Where can I get a smaller water pump pulley? Should I just go to the chevy dealer and ask for a pulley for a 70 half ton truck? I can't put a bigger crank pulley on the car, because a pulley any bigger and it'll hit the front crossmember.

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Justin Traunero
[email protected]
The Club - GM Muscle Cars of the Carolinas

-1967 Camaro SS350 clone - 350/TH-350 with shift kit, CompCams XE268H, Dynomax Jet-Hot headers, Flowmaster American Thunder exhaust, Vintage Air

-2002 Impala LS - Medium Bronzemist Metallic, every option except engine block heater

<A HREF="http://www.furman.edu/~jtrauner" TARGET=_blank>Click here to see my Camaro and my parents' 2002 Impala LS.
</A>
 

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Ahhhh, glad to see some people are taking my advice when I posted these fans would fit on Chevelles over at www.chevelles.com a couple of years ago!!

Here is what they look like on my Chevelle (which is in paint and body hell right now
)

Pic#1

Pic#2

Joe

[This message has been edited by 72SSAbody (edited 05-16-2002).]
 
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