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SBC Overheats, but only after 20 minutes by Saxman
Started on: 11-25-2006 05:33 PM
Replies: 242
Last post by: Saxman on 03-06-2008 04:18 PM
Saxman
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Report this Post11-25-2006 05:33 PM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
Help!

I figured out that the electric fan was blowing backwards, and thought I had the problem licked, but todays run confirmed that is still heats up too much.

So far, I put two holes in the new 180 degree thermostat, got the cooling fan spinning in the right direction and burped the system by jacking up the rear end a couple of times.

I got her out on the open road (if you can call it that around DC) and she was fine for a long time since my trips were around 15 minutes each. The temp went up to 210 and dropped immediately down to 180, then slowly crept back up to 210 again and held there for a long time. At the end of the third 15-minute trip (all within the hour), the temp started to creep up around 230 degrees so I had to bring her back in the garage. Damn!

Right after I shut the engine off, but left the electric water pump on, I listened close to the pump and I could hear the sound of coolant swishing/bubbling through, so I am worried about air I could hear in the system. I don't think I should be hearing that. I let her cool down and was only able to add about 2 ounces of coolant - even after jacking up the rear end.

What next?!?! I don't know what else to do. I plan to jack up the front tonight and see if there is air up there later tonight. I sure wish I had a way to check the timing, but the previous owner (Yons) didn't install a timing mark (among other things). I wonder if I should just back off on the timing a little to see if that is the problem? Or maybe adjust the carb (running rich?) since I can smell gas back there after every run?

Any input would be appreciated. My main repair thread on this car is at //www.fiero.nl/forum/Forum2/HTML/076693.html if you want pics.
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Firefighter
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Report this Post11-25-2006 06:30 PM Click Here to See the Profile for FirefighterClick Here to Email FirefighterSend a Private Message to FirefighterDirect Link to This Post
Sounds like your NEW 180 degree thermostat is defective. If it opened correctly, you would probably not have the problem. Ed

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Saxman
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Report this Post11-25-2006 06:33 PM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
 
quote
Originally posted by Firefighter:Sounds like your NEW 180 degree thermostat is defective. If it opened correctly, you would probably not have the problem. Ed


I heated it up on the oven before installing and it opened at around 185 degrees. I think it is OK. My last resort is to run without a t-stat at all, but that will probably cause it to run even hotter since the coolant won't stay in the radiator long enough to cool off.

Thanks for the suggestion!

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Report this Post11-25-2006 08:12 PM Click Here to See the Profile for prizm-bluegtClick Here to Email prizm-bluegtSend a Private Message to prizm-bluegtDirect Link to This Post
Still sound like your timing is set too high.You run it to 3200 rpm to get the total advance the engine receives.Advance the distibuter till you here popping and crackling from the exhaust.Back the distibuter off till the engine smooths out.Try it there.
BTW what CFM rating fan are you using? If it is around 1000, look into getting a better one from JEGS.
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bmwguru
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Report this Post11-25-2006 08:25 PM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
First, get the fill to the highest point. It sounds like there is still air in there. I think I posted in your last overheat post that I installed a t-stat housing that has the cap built into it. I also used 1 1/2 header pipe for most of the cooling system so it can't expand. I took my Fiero out today and it never went over 190 degrees. and that was including extended idling and smokey burnouts in front of my shop. Running lean and timing too advanced will increase temps, too.
Dave

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Report this Post11-25-2006 09:26 PM Click Here to See the Profile for HarryGClick Here to Email HarryGSend a Private Message to HarryGDirect Link to This Post
Do you have the air deflector (air dam) in place under the radiator?
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Saxman
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Report this Post11-25-2006 10:02 PM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
 
quote
Originally posted by prizm-bluegt:Still sound like your timing is set too high.You run it to 3200 rpm to get the total advance the engine receives.Advance the distibuter till you here popping and crackling from the exhaust.Back the distibuter off till the engine smooths out.Try it there.
BTW what CFM rating fan are you using? If it is around 1000, look into getting a better one from JEGS.


I'll check the fan rating tomorrow to see just how much air flow I have. I'll also check for the air dam, HarryG.

So, I should rev the engine to 3200 and make those adjustments at the same time or adjust and then rev to see how it sounds? Either way, thanks for the advice.

bmwguru, here is my setup:


I have the block with a cap above the thermostat, too, with metal hoses through most of the system. It's corrogated (I think that is what it is called) as you can see to the right of the air filter. I need to find a friend who knows Edelbrocks!

Thanks for the advice, everyone! I'll keep plugging away at it. I just want to be able to make the 45-minute drive to work!
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prizm-bluegt
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Report this Post11-25-2006 10:22 PM Click Here to See the Profile for prizm-bluegtClick Here to Email prizm-bluegtSend a Private Message to prizm-bluegtDirect Link to This Post
Make the adjustments while reved.What size carb do you have.judging by size it looks kinda small.

[This message has been edited by prizm-bluegt (edited 11-25-2006).]

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Saxman
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Report this Post11-26-2006 12:22 AM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
Just an Edelbrock 600. I don't know that this LM1-type engine needs much more, but I am no expert - that's for sure...
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Report this Post11-26-2006 12:46 AM Click Here to See the Profile for HudiniClick Here to Email HudiniSend a Private Message to HudiniDirect Link to This Post
Just a suggestion since I don't have this setup. You mentioned an electric water pump. Can it be wired to run backward or can the hoses be hooked up backward? I have read other folks having a problem because they were given a reverse rotation pump at the parts store. My 3.4L swap gave me a problem with overheating when I used the reverse rotation 3.4L pump instead of the Fiero one.

Also, my experience with my '72 Z28 was no thermostat = no heat. The water temp gauge never rose above ~100 degrees.
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Report this Post11-26-2006 02:37 AM Click Here to See the Profile for TrotFoxClick Here to Email TrotFoxSend a Private Message to TrotFoxDirect Link to This Post
Just to second Hudini, removing the thermostat should not cause further overheating issues. Rather it should cause under-heating issues. The faster the water flows through the radiator the cooler it will become. The thermo's job is to restrict water flow until the block warms and then regulate it to maintain temp. Less flow mean more heat and vice-versa.

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Report this Post11-26-2006 03:00 AM Click Here to See the Profile for tjm4funClick Here to Email tjm4funSend a Private Message to tjm4funDirect Link to This Post
 
quote
Originally posted by TrotFox:

Just to second Hudini, removing the thermostat should not cause further overheating issues. Rather it should cause under-heating issues. The faster the water flows through the radiator the cooler it will become. The thermo's job is to restrict water flow until the block warms and then regulate it to maintain temp. Less flow mean more heat and vice-versa.

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That is true up to a point. no restriction can cause over heating at higher rpm/flow rate, as the water is not in the radiator long enough to have the heat extracted. you would see that with sustained high rpms on a belt driven pump, but an electric is max flow all the time. in an idle state tho, you should not see any over heat with no tstat. I would consider drilling and tapping the top of that tstat housing, and putting a small valve in there to bleed air off, as it will accumulate there at some point. that is common on marine engines where the tstat is the high point of the system.
If you hear the bubbling noise at the pump, it can indicate air and cavitation which will airate the coolant and reduce it;s cooling ability to next to nothing. That is one biatch of a bug to shoot if it is the case, as the only way you can see it is to replace a section of the hose with some clear reinforced hose and watch the flow. once a antifreeze mix gets airated, it takes forever to purge, and drops the cooling to next to nothing.
You really need to find a method that you can fill your system and purge the air out reliably.

for timing it, you can use a vacuum guage too, hook it to manifold vacuum at idle. advance the dist (ccw) til it peaks then starts to drop. retard it til it drops under 18" and almost stalls, set it halfway and you should be close enough to run decently. That tends to have you running slightly retarded, but that is better than too much advance.
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Report this Post11-26-2006 09:26 AM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
I had edelbrocks on my first v8 Fiero. I tried 600 and a 750 and I couldn't tune them. Very poor throttle response, too rich at full throttle, but 22mpg hwy. With my webers, the throttle response is better than injection....simply amazing. But I am getting about 5mpg...but it's a great 5 miles! I ran my water pump upside down to lessen the water hose. I found that the more rubber hose he better chance for expansion causing air pockets. My last fiero would always overheat. This time, it's not an issue. If there are any pics of my cooling system you would like to see for reference, let me know.
Dave
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Report this Post11-26-2006 10:27 AM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
 
quote
Originally posted by Hudini:Just a suggestion since I don't have this setup. You mentioned an electric water pump. Can it be wired to run backward or can the hoses be hooked up backward? I have read other folks having a problem because they were given a reverse rotation pump at the parts store. My 3.4L swap gave me a problem with overheating when I used the reverse rotation 3.4L pump instead of the Fiero one.

Also, my experience with my '72 Z28 was no thermostat = no heat. The water temp gauge never rose above ~100 degrees.


Electric pump running backwards: Interesting, since the previous owner hooked the fan up backwards. I'll have to find a way to check it.

Since the previous owner pulled out all of the heating parts (ALL of them, including the ducts!), heating is not an issue, so I guess I'll try no T-stat if the problem stays after more system-burping.

Again, I cannot remove the T-stat without draining the system, so I will save that until I know all the air is out.

Thanks, Hudini!
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Saxman
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Report this Post11-26-2006 10:32 AM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post

Saxman

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quote
Originally posted by tjm4fun:That is true up to a point. no restriction can cause over heating at higher rpm/flow rate, as the water is not in the radiator long enough to have the heat extracted. you would see that with sustained high rpms on a belt driven pump, but an electric is max flow all the time. in an idle state tho, you should not see any over heat with no tstat. I would consider drilling and tapping the top of that tstat housing, and putting a small valve in there to bleed air off, as it will accumulate there at some point. that is common on marine engines where the tstat is the high point of the system.
If you hear the bubbling noise at the pump, it can indicate air and cavitation which will airate the coolant and reduce it;s cooling ability to next to nothing. That is one biatch of a bug to shoot if it is the case, as the only way you can see it is to replace a section of the hose with some clear reinforced hose and watch the flow. once a antifreeze mix gets airated, it takes forever to purge, and drops the cooling to next to nothing.
You really need to find a method that you can fill your system and purge the air out reliably.

for timing it, you can use a vacuum guage too, hook it to manifold vacuum at idle. advance the dist (ccw) til it peaks then starts to drop. retard it til it drops under 18" and almost stalls, set it halfway and you should be close enough to run decently. That tends to have you running slightly retarded, but that is better than too much advance.


Cavitation is my concern since it takes so long to get too hot. I thought there was something that could be added to cut down the aeration. I'll check it out.

My T-stat cap should be the highest point in the system so I don't know if a bleeder valve is the answer - but I am not eliminating it. Those corrogated hoses have me wondering if they only make the aeration worse.

I'll do what you say on the timing. It sounds ike my only option.

Thanks for your time on this one, everyone!
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Saxman
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Report this Post11-26-2006 10:36 AM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post

Saxman

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quote
Originally posted by bmwguru:I had edelbrocks on my first v8 Fiero. I tried 600 and a 750 and I couldn't tune them. Very poor throttle response, too rich at full throttle, but 22mpg hwy. With my webers, the throttle response is better than injection....simply amazing. But I am getting about 5mpg...but it's a great 5 miles! I ran my water pump upside down to lessen the water hose. I found that the more rubber hose he better chance for expansion causing air pockets. My last fiero would always overheat. This time, it's not an issue. If there are any pics of my cooling system you would like to see for reference, let me know.
Dave


This Edelbrock is much better than the old Holley that was on there last month - that's for sure! Point taken on the Webers, but I want to drive this 25 miles to work . That would get a bit expensive two or three times a week!

The only rubber hose on mine is the few inches to connect the metal hoses to the stock Fiero lines (and the heater hose which runs to NO heater).

Again, I'll burp the system again after I run it with the back end jacked up and do the same for the front to see what happens. If that does not help, I'll drian coolant and pull the t-stat and see what happens.

I'd like to see your setup, though. Feel free to post a shot here if you can do it easily. Thanks!
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Report this Post11-26-2006 10:39 AM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
One question. Is the electric water pump "race only" or "street use"? Check the specs on it. It may not flow what you need. Also, it may be getting worn out if it is old. They only get so many hours before rebuild or replacement.
Dave
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Report this Post11-26-2006 03:12 PM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
bmwguru, it looks like a new one, but I don't have any way to tell if it was used before it was on this car since Yons won't answer my questions.

It is a Summit unit, but they don't sell it any more so I have no idea of what it was meant for.

I spoke with a PFF lurker on the phone today and he suggested filling in the gaps around the fan shroud. Well, I have no fan shroud, and the piece that covers the top of the radiator was missing, so I pulled it off of one of my "future projects" for a try. I also ran the electric pump with the back end jacked up again to look for air, but got nothing.

Just to be sure mine is correct, the coolant should run from the pump INTO the front of the engine, right? When I run the pump with my finger over the thermostat, I can feel the coolant pushing through the holes I put in it.

Another thought: could those holes be aerating the coolant and causing the problem? Of course, the heating problem happened before the holes went in the t-stat, but the electric fan was also blowing the wrong direction at that time...

Right now, I plan to remove the t-stat when the car cools down and see what happens. I'll report in tonight if I get her on the road before dark (because I would hate to have to tow her home in the dark!)

More frustration: At speed on this test drive, the rubber seal around the front windscreen blew of on one side (embarrassing) and the pass. side rear window blew right off!! I heard the noise, but didn't know what it was. Got home and it was gone, so me and my little girs went on a triangle-hunt and found it - scratched on the end and cracked in one corner. AAAAArhg!!!
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Report this Post11-26-2006 04:02 PM Click Here to See the Profile for tripple8Click Here to Email tripple8Send a Private Message to tripple8Direct Link to This Post
Summit Pump

If this is the pump you have, it should have enough flow.

quote
I listened close to the pump and I could hear the sound of coolant swishing/bubbling through, so I am worried about air I could hear in the system. I don't think I should be hearing that.
quote

If you can hear any change in sound/speed you have air. I would not worry about aeration, if you get all the air out this can't happen. As far as cavitation, this really only happens on mechanical pumps at high rpm. Your pump was designed to run at a continuous optimum rpm.

I think you still have air in the system.

Dale

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Report this Post11-26-2006 04:09 PM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
the coolant goes from the t-stat to the top of the radiator. call summit racing to find out if it is a race only pump. If that is the case, it won't flow enough for street use.
One other way of telling if you are airbound is to watch the overflow tank. After it cools, if the tank empties, you have air. Check the rad cap pressure. I run a 13lb cap so the hoses don't expand too much. I also have my overflow in the back, not the front, to lessen the chance of air.
My last Fiero had such bad problems of overheating. I took care of every issue with this one...ie bigger radiator, lower psi caps, less rubber hose, better water pump, 180 t-stat, properly reading gauge, no restrictions, decent fan (no shroud though)etc.
I found that mine would run a little hot with the hood closed at idle. Open the hood and no problem. So I fiberglassed a similiar scoop to the Archie Warbler hood. No problems since. Try taking the hood off and see if your overheat goes away.
Dave
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Report this Post11-26-2006 04:12 PM Click Here to See the Profile for BoominatorClick Here to Email BoominatorSend a Private Message to BoominatorDirect Link to This Post
 
quote
Originally posted by Saxman:


Right now, I plan to remove the t-stat when the car cools down and see what happens. I'll report in tonight if I get her on the road before dark (because I would hate to have to tow her home in the dark!)



Saxman,
Not to worry about pulling the thermostat completely out. I've run a V8 conversion for many years, both with a thermostat (using 160F, 180F, and 195F) and without. There will be no difference in the ultimate temperature that the car runs. The thermostat only serves to get the engine up to heat faster to lessen emissions & aid in cold drivability. The cooling system will stabilize at whatever its maximum thermal capacity allows during high ambient air temperatures - exactly what happens when the T-stat opens. Of course, as one other poster stated, the car may actually run too "cold" without the T-stat, in cooler ambient air temps. With regard to the coolant flowing through the system too quickly without a restrictor & running hotter as a result of no T-stat...NOT in a Fiero. Given the distance, the pipe diameters and number of twists & turns that coolant is required to flow in the Fiero - there is plenty of built-in "resistance". As you may remember, I was having the same trouble that you are experiencing. I must have bled my cooling system 20 times before I actually expelled all of the air. It seems to be fine now.
One other possibilty that comes to mind with regard to overheating is a head gasket leak that causes both extra heat and pressure to enter the cooling system. Do you have access to a hydrocarbon sniffer? If so, run the car with the radiator cap off & check for combustion gases. You may have covered this, but late ignition timing can also result in running hot. Is your vacuum advance system working correctly? BTW, you definately should be running a cooling fan of the full shroud design. Some of the non A/C, manual tranny Fieros came with cooling fans that simply mounted via an open "X" brace design.
Good Luck & keep us posted!
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Report this Post11-26-2006 04:14 PM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
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Report this Post11-26-2006 04:14 PM Click Here to See the Profile for Jake_DragonSend a Private Message to Jake_DragonDirect Link to This Post
Here is my setup, no heater hoses at all.

Both caps are the same but the back one has the over flow plugged.

Coming out of the pump turning down to the pipe going under the passenger side of the car

The intake hose uses both steel and rubber. I used the old crossover pipe off of the 2.8

Hereís how I filled and burped my system.
Take the cap off the radiator. Using a water hose fill each hose until no more air comes out of the radiator and put the cap on and run the hose in the intake hose until no more air comes out of the return hose. Fill the intake with the water hose until you see water coming out of the water pump, then hook up the hose to the water pump. Leave the thermostat out and hook up the intake hose and run the electric water pump without starting the car. Let it run for a few minutes and check the water level at the back of the car, do not open the front until your ready to add antifreeze. Do this a few times until you donít have to add any more water to the system then its time to start the car. Let the car run until it gets above 180 and shut it down. Let it cool and check the water level. I had to squeeze the intake hose a few time and it let me add about 2 water bottle. Now start the car and let it run up to 180 and do it all again. Once you are not able to add any more water let it warm up to 180 and check for leaks, if you donít see any its time for a test drive. After you get back let it cool and check the water level. If its ok and it didnít over heat your ready to put your thermostat back in and to add antifreeze. I jacked the front of the car up so it was just below the level of the back cap then poured antifreeze in the intake hose and let it run out of the radiator. Once you have enough antifreeze added to the system you will have to burp it again but it wont be as bad. I just had to run it up to 180, let it cool and top off the water level one time. This has worked for me every time.
I have been running a stock V6 radiator with a stock shroud. If you have an aftermarket radiator then you should try and find a shroud that blocks off all of the radiator except where the fan is, check the sides of the radiator and make sure air isnít getting around it instead of going through it. Also make sure your front air dam is in good shape so you get air into the radiator and not just going under the car.
Good luck.
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Report this Post11-27-2006 10:52 PM Click Here to See the Profile for RTNmsdsClick Here to visit RTNmsds's HomePageClick Here to Email RTNmsdsSend a Private Message to RTNmsdsDirect Link to This Post
 
quote
Originally posted by Saxman:

I spoke with a PFF lurker on the phone today and he suggested filling in the gaps around the fan shroud. Well, I have no fan shroud, and the piece that covers the top of the radiator was missing, so I pulled it off of one of my "future projects" for a try. I also ran the electric pump with the back end jacked up again to look for air, but got nothing.


Sax... a couple of things about my SBC experience that might help you (as I too picked up a project from someone that never could beat the overheating issue)....

1) You really need the fan shroud. Without it you just don't get the air pulled through the radiator like you need. Instead, the air just circulates around under the deck lid. Talk to Archie about it. I think it was Archie that figured out that sealing the edges of the fan shroud actually helps with cooling.

2) Make sure you have an air dam under the radiator to pick up air at speed. Otherwise you'll have a car that can putt around and keep temperature, but will heat-up quicly when you get to highway speed.

3) Check the serial numbers on your block & heads. Older SBC's were designed to run at 220-230 F, and no matter what thermostat you put in there the motor just wants to heat up to that point. Even with a 185 stat, I don't get worried about mine running hot 'till I start to push up to the 235+ range. (Motor numbers suggest that my SBC was from a '70 Nova.)

When I first got my car running, I could barely drive 5 miles without the temp getting up into the red. Simply by improving the air flow across the radiator (by removing restrictions in front of it and adding the air dam beneath it), I've put over 6000 miles on it now without problems. Still wants to push a bit warmer than I would like on a really hot southern summer day, so I'll be looking more closely at point #1 this summer 2007. For right now, the car won't push the temp that high since the outside temps are cooler.

I have felt your pain, and don't envy you at all. Hope some of this helps.

[This message has been edited by RTNmsds (edited 11-27-2006).]

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Report this Post11-27-2006 11:01 PM Click Here to See the Profile for RTNmsdsClick Here to visit RTNmsds's HomePageClick Here to Email RTNmsdsSend a Private Message to RTNmsdsDirect Link to This Post
 
quote
Originally posted by Jake_Dragon:

Here is my setup.....


Jake,

What is your SBC out of ? What heads are you running? What temp do you stabilize at crusing at 80 mph in the FL summer? Is the SBC in your 308 kit?

Just curious as you are even deeper into the climate "hot zone" than I am.
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Saxman
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Report this Post11-27-2006 11:05 PM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
Please don't think I am ignoring you guys. I only have a little time this week because of work (I get to sit in with the Airmen of Note through January!) and I'll be working several other concerts in DC, so next week is my week to hit the garage again.

I'll work on a shroud before I pull the t-stat. I remember Archie's overheating thread - and that phone call to the silver Fino owner - both make me think the shroud will really help. The 4-core Nova radiator hangs really low, so putting the air catcher down there will get pretty close to the ground. I should just tape up some cardboard for now to test her out.

I'll post more when I get the proper garage-pass!
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Report this Post11-28-2006 06:23 AM Click Here to See the Profile for Jake_DragonSend a Private Message to Jake_DragonDirect Link to This Post
 
quote
Originally posted by RTNmsds:

Jake,

What is your SBC out of ? What heads are you running? What temp do you stabilize at crusing at 80 mph in the FL summer? Is the SBC in your 308 kit?

Just curious as you are even deeper into the climate "hot zone" than I am.


Its a 4 bolt main, I dont have the exact numbers but I think its out of a 70s truck or Vette. It has been bored over between 40 and 60, cant get a straight answer from the builder because I bought it already done. The heads have the bigger valves but they are stock heads. It has an aftermarket cam but I dont know what it is, its not stock you can tell by the idle. I havent done a lot of crusing but after a 30 minute spirited drive it stays at around 190 - 200 with the fan on. But will drop to 180 when I take it easy.
My radiator has a full fan shroud and the shroud at the sides and top of the radiator are in good shape. I run the fan with the AC button right now because if I run it all the time the car wont heat up. I dont have any heater hooked up and right now I dont have a thermostat. I have probably around 1000 miles on it from the time I put it in my GT.
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Report this Post11-28-2006 10:03 AM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonDirect Link to This Post
 
quote
Originally posted by Saxman:

Just an Edelbrock 600. I don't know that this LM1-type engine needs much more, but I am no expert - that's for sure...


mine had a 383 originally and Jegs recommended a 550cfm and it worked better than the orig 650. Had a lot better throttle response and bottom end. Since I never intended to race it, just drive it on the street, I wasnt concerned with it running out of top end.

Just thought of something else discussing carbs...You might be running the carb a little too lean that would cause it to heat up. On my Cessna, you have a mixture control the richens or leans your fuel mix from the cockpit. I have been in really hot weather and ran it richer to keep cyl head temps down. Just something else to play with and it wont cost anything to readjust it

Are you also sure you dont have any restrictions in your cats, mufflers or exhaust pipes?

[This message has been edited by rogergarrison (edited 11-28-2006).]

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Report this Post11-28-2006 11:57 AM Click Here to See the Profile for Jake_DragonSend a Private Message to Jake_DragonDirect Link to This Post
I also run a little rich, not enough to foul the plugs but enough to not worry. I went from a 650 down to a 600. The primaries in the 650 are bigger then the secondaries in the 600 The Holley 650 primaries and secondaries were the same size. The edelbrock has smaller primaries and larger secondaries. Its also better on gas.
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Report this Post11-28-2006 12:04 PM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
Here are some pics of my cooling system setup that you wanted to see.

This images is larger than 100K. Click to view.
the upside down electric water pump-to put the feed line closer to the passenger side coolant pipe.

This images is larger than 100K. Click to view.
oversized radiator w/ electric fan-don't mind the nose, the car hasn't been to the paint shop yet.


the custom made coolant pipe. made from header pipe J-bends. This keeps the rubber hose from expanding causing air pockets-a problem with my last V8 fiero.

pretty much I ran into many problems with my last fiero's cooling system. So far, I seemed to work out all the bugs. It hasn't run hot yet.
Dave
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Report this Post11-28-2006 12:56 PM Click Here to See the Profile for 3084meSend a Private Message to 3084meDirect Link to This Post
Nice setup.

You're really getting things done on that car.

One suggestion incase nobody has mentioned it. You really need to get some sort of shroud around your electric fan or a fan with an integrated shroud. You've got quite a bit of "unused" surface area there that you can be "optimizing" at idle with the use of a shroud that will allow the fan to pull air through a larger area.

I always look when I'm in the junkyard to see which other cars have an integrated shroud that I can remove the original fan from and install a higher CFM unit into. The nice this is: Some Saabs and imports have a pretty lager radiator so finding a plastic shroud that can be modified and pretty easily found. I'll be on a hunt for one during the next few weeks. I'll let you know what I come up with..

Keep up the good work.

[This message has been edited by 3084me (edited 11-28-2006).]

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Report this Post11-28-2006 01:03 PM Click Here to See the Profile for Tim KClick Here to Email Tim KSend a Private Message to Tim KDirect Link to This Post
I sure am glad I read this thread, because I still have overheating problems with my F.I. 383 SBC. I have pretty much done what everyone has suggested e.g. sealing the shroud, Summit fan (blowing the right direction), bigger Archie radiator, getting air out of the system, Summit electric water pump, and no thermostat. I still can't drive the car to Chicago on an 90 temp day, because it will overheat if I get stalled in traffic. It really ticks me off that I can't drive the car where I want to when I want to. Archie was called and surmised that I had a restriction somewhere in the system, but I have checked all the lines, and pulled down the side water pipes and checked them, and I don't see it. I am going to pull out the new radiator and have it checked for flow, but I think that will be a wasted effort. It seems that once the temp starts rising above about 230, there is no stopping the temperature climb unless I shut it off, even if I raise the hood. I am going to see if I can put an even bigger radiator in it than the 4 core I got from Archie. Absent that, I am starting to believe that my Fiero will never visit Chicago in the summer and Victory Auto Wreckers will have themselves a Fiero less engine (grin).
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Report this Post11-28-2006 03:17 PM Click Here to See the Profile for 3084meSend a Private Message to 3084meDirect Link to This Post
You know what's funny?

Every now and again, you hear of people using the stock V6 Rad.. My last V8 car had a custom Radiator (not Archies though) and seemed to do ok but did get a little warm. Especially with the A/C on. I can't remember if my dyno slip was from the chassis dyno or the engine dyno but my best was just a tad under 430HP. Hey , even with a 17% "driveline loss", I had a lot of fun in the car but I did feel that it was bit too much for the street. (Ran hot, lumpy idle, etc).

For this swap, in addition to keeping the HP way down in the 290-315 HP range, I think I'm going to go with one of the Summit 26x 19'ish racing rads. I've had some pretty good luck with the 2 large 1" cores and I seem to agree that they do seem to "outcool" the typical 4 core rad. Although Aluminum is my 2nd choice for a Radiator , I am comming around a bit on the idea. They seem well built and once a die hard Copper / Brass guy, I like what I see with the aluminum.

I know that others has mentioned to just use the stock V6 Rad but I really have no intention of doing so. Also, FieroGuru and I have e-mailed quite a few times about his great idea with using the 4cyl waterpump mounting setup. In fact, just incase I wanted to try it, I bought his adapters that he fabricated to bolt to the block with barbed ends to attach hoses to for the pump which is mounted in the A/C bracket from the Archie kit.

In my case, I want to retain the A/C so that's out of the question. I think for me, it's going to be the aftermarket radiator and electric pump to start. I'm always looking at the cooling threads to see what everyone has done. Especially now that my cradle is out and I'm test fitting the SBC now and I'm getting close to putting everything back in the car.

[This message has been edited by 3084me (edited 11-28-2006).]

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Report this Post11-28-2006 03:22 PM Click Here to See the Profile for 3084meSend a Private Message to 3084meDirect Link to This Post

3084me

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Member since Apr 2005
Hey bmwguru,

Do you have a larger pic of the top of your engine. Great looking setup. I have a 308 replica and am looking to "disguise" the SBC just a bit. I love your intake setup.

Right now, I have a set of European Valve Covers and a few old Euro Cam Covers from OHC engines. I'm modifying my centerbolt valve covers to act as a mounting point for a "faux" valve cover. I also have a few plans for a cover for the HEI distributor as well.

Not that it's needed on a Fiero (or my replica for that matter) but I think what you've done is a great touch and very unique.

[This message has been edited by 3084me (edited 11-28-2006).]

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Report this Post11-28-2006 03:38 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonDirect Link to This Post
Like I said before, my 383 4bbl ran fine in ohio summer with OEM 4 cyl radiator. I used archies belt drive water pump...I dont trust electric ones. I had no special vents or front end mods, oem shroud. However I did not have AC either. It did have an auto that used the stock radiator cooling tube too. I ran a 160 unmodded thermostat. All the radiator hoses were the ribbed bendable ones with no pipe runs except the OEM thru the rocker tubes. BTW for info, the radiator I replaced in my C4 Corvette was almost identical (2 row, same dimensions) as the one in my Fiero. I had them both laying on the garage floor at the same time.
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Report this Post11-28-2006 03:54 PM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruDirect Link to This Post
 
quote
Originally posted by 3084me:

Hey bmwguru,

Do you have a larger pic of the top of your engine. Great looking setup. I have a 308 replica and am looking to "disguise" the SBC just a bit. I love your intake setup.

Right now, I have a set of European Valve Covers and a few old Euro Cam Covers from OHC engines. I'm modifying my centerbolt valve covers to act as a mounting point for a "faux" valve cover. I also have a few plans for a cover for the HEI distributor as well.

Not that it's needed on a Fiero (or my replica for that matter) but I think what you've done is a great touch and very unique.



I bought the webers three years ago for about $2,000 new. I was paralyzed in a freak incident and didn't install them until spring '06. (I have fully recovered by the way). Now they go for about $3,500....damn markup!!!
Anyway, are some better pictures.
Dave

This images is larger than 100K. Click to view.

------------------
[

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Report this Post11-28-2006 04:11 PM Click Here to See the Profile for GKDINCSend a Private Message to GKDINCDirect Link to This Post

This is one side of my cooling system. From the intake manifold to driver side Fiero cooling pipe. Hole drilled in the old battery location area. Gets the pipes out of the engine bay.
Good Luck
Gary
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Report this Post11-29-2006 01:59 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonDirect Link to This Post
 
quote
Originally posted by bmwguru:


I bought the webers three years ago for about $2,000 new. I was paralyzed in a freak incident and didn't install them until spring '06. (I have fully recovered by the way). Now they go for about $3,500....damn markup!!!
Anyway, are some better pictures.
Dave

This images is larger than 100K. Click to view.



Very cool looking engine. I had webers on my GT40 when I got it. I never got finished getting them to run right before someone bought the car from me.

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Butter
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Report this Post11-29-2006 05:16 PM Click Here to See the Profile for ButterClick Here to Email ButterSend a Private Message to ButterDirect Link to This Post
Hey Sax I read through most of your post but not everyones.
Things to check from my experience--
Check to make sure there are no crimps or pinched places on the long pipes under each side. Pay attention to the bends in the front. Some racks can catch those pipes while backing off of them and slide them forward causing a kink in the stock bend.

Check to make sure there isn't a split in those hoses too around those bends. This can happen if the pipes have been slid forward as above referenced. Had to patch one on mine after a lift visit.

Check to make sure the intake side (right side) hoses are in good shape. I have witnessed old hoses collapse when heated up and they can't draw any coolant then.

One of the biggest headaches I've had locating an overheating problem was the impeller was slipping on the pump shaft on a newly replaced water pump (bad new pump but looked perfect) This caused a problem much like you describe as the pump worked great till it warmed up good. Some electric pumps use a set screw to connect it to the pump shaft. My first CSI pump was this way and it lent itself to a slipping impeller. CSI changed that to a screw on impeller and upgraded a weak seal on later versions.

Check the Radiator cap and seat to make sure it is sealing well. On some radiators the seat is some sort of plastic and they can become defaced. Brass can also accumilate debris and cause problems.

Check the radiator to make sure when the car is running before it gets pressure the flues are flowing out and not squirting out. Squirting out is a sign the flues are clogged up and need rodding.

Check to make sure the electric pump is connected well and listen to make sure the brushes in the pump are not turning loose after it gets up to temp. The push together splices are convenient but not effective. Either one of those problems will cause an over heat condition and I have had both at one point do it. Make sure the wire used to connect the pump is heavy enough to carry the current your pump uses and is connected to a heavy enough circuit. I used the coil wire on my setup.

There are other issues that can cause over heating but the ones I have mentioned I have experienced. Hope this helps.
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Report this Post12-04-2006 02:11 PM Click Here to See the Profile for SaxmanClick Here to visit Saxman's HomePageClick Here to Email SaxmanSend a Private Message to SaxmanDirect Link to This Post
I finally have time to get back to the car. Thanks, Butter, and everyone else for the info.

I've left the rear end jacked up for the last week, and when I went out to play with her a little, I noticed that the coolant overflow resovior is completely full to the cap. When I pulled the rear cap, there was a lot of coolant missing. I can only figure that it all went up front into the overflow.

Could the cap (a brand new one) be letting coolant by (I don;t know if it was that full before I jacked it up while it was hot), or perhaps the air bubble worked its way out the back since has been jacked up? I ran out of coolant when refilling today, but will have more on the way. Maybe I'll just fill her up and take her for a spin to see if anything has changed...
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