1988GTA500HP

I have an 88 GTA with a 400ci in it and uncoated headers. It gets pretty hot under the hood in Florida and I was thinking of adding either scoops or louvers to the hood to exhaust the heat. I certainly don't want rain entering the engine compartment uncontrolled so have been trying to come up with a fairly easy (read inexpensive) way to route the rain out. I will be replacing my hood soon so am willing to experiment on the old one before hacking at the new hood. Anyone see any problems with this design? Thanks so much for your input.

//<86TA>\\

iTrader: (14)

nope, a rear opened scoop will pull air in, not let air out (same as a cowl induction hood), unless you fashion a wickerbill to it and try to make the air reverse direction.

You can try to fabricate a reverse cowl, or heat extractor hood, search the fab board for it, a member made one a while back. It puts a opening just behind the radiator in the hood, and the idea it to take air passing through the radiator that would normally be forced out the bottom of the engine bay, up and out.

water will get into the engine bay from underneigh the car, so i would not worry so much about that aspect, so long as it it not allowed to run directly into a throttle body or carburator.

1988GTA500HP

Thanks, 86TA. Same if I used louvers? I will search for the heat extractor hood but was hoping to get some of the engine heat extracted as well, not just the radiator heat.

I wonder if anyone makes a big block corvette style hood from the early 70s that seems to combine the cowl induction scoop with a reverse cowl at the front.

taonindo

this works for me

1988GTA500HP

That looks pretty cool, tao. Did you do it yourself? I already have a cowl hood to work with. Did you buy those inverted scoops? Did they help with engine cooling? I was thinking of adding four inverted scoops something like the attached picture. Can't be too hard to fiberglass. (I hope).

1988GTA500HP

Or with the rear ones slanted the same as the front ones. I think this one looks better.

taonindo

i like that second one too. im not good at fiber glassing and such so.... my vents are from a trans-am fender, and yes they seem to help alot. in a 2 mile hillclimb im down 20 degrees temp from last year, i think thats alot.

Brad96

iTrader: (1)

I'm not an aero expert, but don't think that a rear-opened "scoop" will necessarily draw air INto the engine compartment. With a cowl-induction hood, the rear-facing opening is supposed to be in the relatively higher air pressure area right in front of the base of the windshield. A rear-facing opening further forward on the hood might help to get air out. I know, the 2nd-gen cars had rear-facing shaker scoops. I'm not sure that was generating any real ram-air effect, though.

Regardless, I definitely agree about louvers and wickerbills. Look at the hood and front fenders of closed-wheel race cars that are allowed such features. They often run lots of louvers over and just behind the front tire bulges, where the body curvature helps to create low pressure areas. These types of features are likely to be more efficient than rear-facing scoops.

1988GTA500HP

Wow....20 degrees. I'd take that anyday.

1988GTA500HP

Thanks for the input, Brad. I wondered the same thing on the scoops. I'm leaning toward an inverted scoop or louvers to let the heat out. I'm thinking one set behind the radiator and one set near the back should let out a lot of heat.

paul_huryk

You need to have larger scoops than your illustration to let out all the heat a V8 can put out...

1988GTA500HP

Really? Thanks for the input Paul. Would I need like 2 or 3 of the rear ones on each side? My engine will get up to 235 in traffic here in FL and I know anything would help, but the more the better. I could make each one progressively bigger without crossing the seam in the hood.

customblackbird

iTrader: (15)

Your cooling system is inadequate, or not working properly. NO reason EVER a SBC should reach those temps if you cooling system was designed/operating correctly. If your running the stock fan switch/thermostat then there should be your first changes. I ran a 383 HSR in my bird with a Jet or hyper tech 180 on 166 off fan switch (both wired to come on the same time) and a 160 thermostat and I ran around NJ in the summer 100* temps with a 3000 stall converter and my temps never got above 180* and that was with a stock rad, stock fans, and a mixture of water, water wetter and rad fluid.

Now my current firebird has a 521 BBF.... YES A 521 big block ford, this motor is 3 times larger than a SBC and Im running a universal 31x19 summit single pass aluminum rad 3" thick, 2 core. using electric fans from a 2005 charger, high flow aluminum water pump, 20lb rad cap, no thermostat just a gutted stock one as a restrictor, and its filled with straight water and water wetter. The hood is a 4" cowl glasstek and the top of the carb sits 2" above the top of the fender. I made my headers, 2" primary, painted with POR20 paint and wrapped with DEI titanium header wrap. driving around with a 3000 stall 3 speed in the same NJ summer temps and this thing stays around 180-190*.

If I can keep my motor cool that has 121 more cubes and takes up my WHOLE engine bay (not kidding its massive and beautiful) yet yours is getting to 235 then you got some issues u need to take care of first. The fact that your motor is heating up in traffic means you don't have enough fan, get more powerful fans. The rule of thumb is if your overheating below 35-40MPH then its your fans, your cooling fans are suppose to flow enough air as if the car is moving up to those speeds. Once you get over 40mph the fans actually become a restriction and will hurt cooling. Hence why competitive racers will use vents on hinges on the fan shrouds so when the go faster than 40mph the higher pressure of the wind entering the rad can escape through the vents and bypass the fans.

1988GTA500HP

Thanks for the feedback, custom. I will try making changes to my cooling system first. I have flushed the cooling system 3 times in the past 2 years hoping maybe it was a piece of rust or something that would flush out. Antifreeze seems to be fine. It only gets hot sitting in traffic. Once I'm moving it cools right down. When I bought the car it had a new aluminum radiator in it so I will try to work with that. It has the stock thermostat and fan switch. I added a switch in the cockpit so I can turn the fan on manually if I have to but would prefer it to work as designed. It has a single electric fan. The headers aren't coated and I have read some horror stories about using header wrap, holding moisture and rusting out the header in short time and such so I was avoiding doing that even though I researched it because I wanted to do that. I am ordering a new hood anyway and really like the glasstek which is a 4" cowl where my current hood is a 3" cowl. Not sure how much that will help.

So I guess my line of attack will be to first change the thermostat to a 160 and see if I can get a lower temp fan switch. I will put the 4" cowl hood on when it comes and if that doesn't solve it, then I will upgrade my electric fans to a dual setup. And lastly, I will wrap the headers if required. Does that sound like the right approach?

taonindo

your right they wont suck air in, they would draw air out,but you have to be moving for them to work. the ones in my hood are not very big but they sure do move a lot of heat, or maybe its just a fluk. guess i could tape them off at the next race just to see.....

customblackbird

iTrader: (15)

2 things I would do is, the thermostat and the fan switch. I might have a 200 on 180 off Jet fan switch laying around. But you can get them new from summit etc for like 50$ i think plus shipping. Depending on what your wanting you can go with either the 200 on/180 off or 180 on/166 off. The 200 one would be better if you want a little more efficiency from the engine and you want enough heat for your interior heat/defrosters for the winter or cooler months. The 180on/166 off would be better if you want your motor to run cooler.

You should match the thermostat to the fan switch, get a high flow thermostat, mr gasket etc sell them. if your going with the 200/180 switch then get a 180 stat, if your going with the 180/166 then go for a 160 stat.

these 2 things should help with slowing your heating down, bc the fluid and fans will circulate sooner. However I think your single fans is the problem. Heres my thinking, if your fan was large enough then when the manual switch/fan switch was activated normally the temps should not increase more than what the thermostat was set for to open at. Since your still overheating when the fans are on and you don't have a 235* stat in then your issue is your fan is not pulling enough CFM to cool the added cubes etc. THis is proven bc once your car is moving then the temps drop. A quick question, if you left the car sitting when it was hot and you gave it alittle gas, say 2000 does the motor heat up or cool down? If it cools down then your water pump isn't moving enough fluid. and then that should be changed out. If your running under drive pullies take them out and throw them in the garbage and then retest.

Now since pulling the fan temp switch in the head will allow coolant to drain out i would take this time to accurately adjust your water to antifreeze ratio. As we all should know that antifreeze is basically glycol and water, however antifreeze does wat the name says. It lowers the freezing point of water, but at the cost of thermal conductivity, basically the amount of heat the fluid can retain and bring to the radiator to be cooled down from air. Which is why the bottle/jug of antifreeze says to mix with 50/50 which should give you a -35*F freeze point. This is a general estimate of climate and where the car will be driven as mostly nowhere on the planet gets to -35*F which means the cars fluid will never freeze and crack the block. But since antifreeze reduces the waters affect to cool then the LEAST amount of antifreeze should be used as it reduces the cooling efficiency of the fluid and the entire cooling system. Now you state that you live in florida, does your temps ever reach 32*F (the freezing point of straight tap water)? I highly doubt it, so your running around overheating with an over dilluted cooling system which is reducing the efficiency of your already inadequate cooling system. So please reduce the your cooling mix to the climate of your area. If your temps reach 30* in say the winter... then mix the fluid so it reads 10*F or 0*F, I like to mix my daily driver in NJ which sees 100+*F and stupid high humidity in the summer and 0-15*F in the winter to about -10*F on my coolant tester/reader. This gives me a little safe margin if the temps decide to get lower than usual. But it allows me to run a better water/anitfreeze ratio for a more efficient cooling fluid all year around. If you wanted to get crazy then swap out the cooling system every fall and spring to reap the most benefits. Which is what I do on my firebird bc it doesn't get driven in the winter and is stored outside. If I lived in florida where it never got lower than 50* i would be running straight water and an additive in my high performance 3rd gen.

Now you should never run straight water in the cooling system. Antifreeze has 2 other purpose besides lowering the freezing point of water, it lubricates all the seals in the cooling system (water pump bearing seals) and it also inhibits the corrosion of the metal/aluminum/brass materials that come into contact with the fluid. Some ppl run straight water but they run Distilled water which doesn't have the minerals that tap water does so it doesn't corrode, but they lack the lubrication of antifreeze which is where cooling system additives come into play. Like water wetter etc. These add additives to the water to reduce the corrosion of straight tap water and add lubrication to the fluid for your seals. These additives/water wetters can also reduce the efficiency of the straight water slightly (it gets ever complicated so take my word for it) but the added efficiency of the straight water outweighs the potential loss by the additives negative affect. They don't say that on the bottles and is actually the exact opposite but its the truth. The gains that are seen with things like water wetters if you look at the bottle is when its used with straight water and thats bc of the straight water.

I won't get into it much bc I dnt remember if you've upgraded your water pump. But if your running to high flow a pump then you can actually reduced the efficiency of the system and fluid. This is by now allowing the water to absorb enough heat bc its moving through the engine to fast. A stock pump might not be enough flow tho as well. Underdrive pullies will usually slow your accessories down as well and can cause charging/cooling issues at idle.

Sorry for the rant but if you know all the facts you can make a better more intelligent decision on what to proceed with next. Thus saving you money and time in the process. You could replace the entire cooling system before you stumble on the right fix.

But this is what I would do.
1. swap out the fan switch for the temp you want, make good connection here and check electrical connections at fan.
2. swap out the Stat for the correct temp of your fan switch.
3. since some fluid will be drained from the block/rad ( i would drain the hole rad if it has a drain plug like the stock one does) I would then add the correct water to the system to come out to the correct ratio for your climate. Remember that some fluid will stay in the block and should be accounted for when adding. You might just need to add straight water and it will mix with whats still in there. Depending on the amount of antifreeze used/still in the system you might want to pic out some water wetter or equivalent to add to the system to bring back the lubricating abilities of the fluid. If not enough antifreeze is used then there won't be enough lubrication. I would say if your above 0*F then add some water wetter. A whole bottle of water water is good for an entire cooling system so don't over do it bc it will have a negative affect on cooling. Don't forget to purge the cooling system of air afterword.

IF your still overheating then my next upgrade would be the fans. which Im sure is your problem bc a single fan unless its a beast 16-18" mark IV is prob not enough for your larger than stock engine.

novaderrik

i put a pair of cheap 8" X 8" furnace air return vents in the hood of my car, and it keeps the temps down quite nicely. it's also pretty cool seeing the heat radiate out of the vents at stoplights when the electric fan kicks on. one of them was right over the alternator, so i made a quick and easy deflector out of some aluminum flashing to keep the rain from drowning the alternator..
it doesn't look totally stupid, but my car is also a $400 POS that will never be pretty- almost like a late model rat rod or something- so that should weigh into your decision to copy it..

taonindo

i like it, just like mine built for use not for looks.

1988GTA500HP

Wow, Custom, that is a lot of information. I appreciate the time.

I did both of those over the weekend. I had a 160 degree stat already because I was thinking of changing it before. I popped that in this past weekend. The lowest temp cooling fan switch I could find locally was an echlin FS111 from NAPA which is rated 204-220 so I put that in as well.

I was thinking the same thing. Since it cools right down when the car is in motion it seems that the radiator is not getting enough air across it when in traffic. The fan is a summit G4904 whcih is 16" and 2010 cfm with 8 blades. However, there is quite a bit of radiator outside the fan and there is no shroud.

I haven't tried giving it gas at idle when it was hot. Seemed kinda like poking a bees nest but I will try it.

I did not know that. I had always heard that you have to add water to antifreeze to activate it. Winters down here are short and the temp does drop to around 40 degrees in the early mornings. Occassionally, we do go below freezing but only for 4 or 5 hours at a time. I just put 50/50 back in when I replaced the switch and stat. I will reduce the water/antifreeze ratio.


That I knew.

It has an aluminum water pump which was already on the car when I bought it so I don't know whether it is high flow or not. I was able to get the engine builder's phone number and gave him a call but it seemed like I was bothering him so I didn't get much info. He said he got the 400 out of a motor home. It has a 2 bolt main. He then rebuilt it completely with parts and knowledge from Summit Racing. I have some of the paperwork for the parts, which is how I got his phone number, but nothing about the waterpump. He did say he wished he had that engine back because the sound always turned heads.


Believe me I really do appreciate all the help.

After I swapped out the stat but before I got the coolant switch, I ran the car to check for leaks. No leaks but I let it idle to check the fan as well. As I mentioned before, I ran a wire from the fan relay ground wire to the cockpit though a toggle switch and to ground so I could turn on the fan manually. I tested the toggle while it was warming up and it worked fine. I also ran a wire from the fan power wire at the relay to a LED in the cockpit so I can see when juice is being sent to the fan. That worked as well. I let the car idle until it hit 230 and the fan never came on automatically. Not a big deal with the toggle on board but I would still like it to work. Then later on Saturday I got the coolant fan switch (NAPA had to get it from the warehouse), installed and retested. Again it didn't come on automatically. Since it works when I grounded it with the toggle I know the relay is good. I then checked continuity between the coolant fan switch connector and the ground wire at the relay. No breaks there. That left in my mind 3 possible problems: 1. Bad coolant fan switch, 2. poor connection between coolant fan switch and connector, or 3 bad engine ground. I ran a continuity test between the head and the battery ground. As long as I twisted a little with the probe on the head (to get through any gunk or oxidation I assume) I did get a resistance number. So I tried tightening the coolant fan switch some more even though it didn't leak. It came with some teflon tape on it. I am never sure whether to use that on anything that grounds to the head or the intake but I guess the threads cut through the teflon pretty good when installing, at least I hope.

So anyways, I took the car to work this morning to test. I live about 8 miles from work with a quick stop for a breakfast sandwich at the halfway mark. Assuming my temperature guage sending unit is accurate, I ran between 155 and 160 prefood. The fan LED lit once for about 30 seconds when it hit 160. Postfood, after the car was off for 4 or five minutes, the temp climbed quickly to 215 or 220 and then the fan LED came on for about a minute. It stayed in that range for the rest of the commute, without the fan coming on again. Now it rained last night and it was cooler this morning than usual, about 71 degrees so the real test will be the ride home this afternoon at about 91 degrees outside. I will try poking the bees nest then

I wondered about this as well. I've heard that not all systems need bleeding. I'm not sure if mine does or not. It has a coolant recovery tank. After flushing and refilling the system, I did have air bubbles coming up in the recovery tank and I then topped the fluid in the radiator. Now when I replaced the thermostat, there was coolant right up to the stat on both sides. There also is a bolt in the intake right next to the coolant knuckle vertically installed. It is a Summit high rise aluminum intake. Do I need to remove that bolt when refilling until fluid comes out the top? Thanks again for your help.

1988GTA500HP

I like it too. I already have a number matching antique car full of shiny bits so I am leaning toward rat with this car. Cheaper parts and less stress about what is correct. If I can't get my cooling system up to par I just might do something similar. Thanks for the reply.

customblackbird

iTrader: (15)

Newer cooling systems are constant bleeding or closed systems. Ours is not that system. The cool an recovery tank is when pressure builds the fluid pushes past the rad cap into an overflow tank, as the engine cools the fluid should get sucked back into the radiator. I run the rad cap off the rad when i start the motor cold. you will actually see the fluid move when the stat opens. adding fluid to the radiator as the air is bled out. Be careful bc as the coolant heats up it will expand and the fluid could come out of the rad when the cap is off, keep an eye on it. Air coming into the over flow tank isn't good, that means air is being pushed past the rad cap which means theres prob air in the system. How old is the rad cap? has it ever been replaced? if Not do so now. Overheating can also be caused by excessive cooling pressure. THis can be caused by a blown head gasket which allows combustion gases to enter the cool ing system but will show no signs but excessive engine temps, and fluid being pushed into the overflow tank. This can cause problems like blowing hoses and radiators etc. A test for that would be to put a rad pressure tester on the rad filler neck and see what pressures your seeing when its nice and hot. U can rent them from auto stores or buy one its a good thing to have. Your rad cap is prob around 16lb, if your seeing more than that on the pressure tester then you got a problem. then you should get a leak down tester and test to see if you get air into the cooling system or if yo have a blown/leaking head gasket. They can fail and you don't have to burn coolant, they can be very sneaky. You shouldn't need a higher pressure cap with your setup but the more pressure you put the cooling fluid under it actually raises the boiling temp of the water/coolant. About 3*F for evert 1lb increase. So raising from a 16 to a 20 gives you 4x3=12*F more boiling temp to that fluid. Not sure about that intake, pics would help. But another good thing to do when purging the coolant system is to raise the front of the car up, getting the rad cap at the highest point helps get air out of places in the heads/block that can cause vapor pockets and cooling issues not to mention destroy your engine/parts.

1988GTA500HP

The Jet coolant switch at Summit is a 195 on/185 off, part 60600. So that should be coupled with the Mr. Gasket 180 degree high flow stat, part MRG-4364?

I measured the fin area of my rad and it is 26w x 17h. A through the rad type mount would be easier to install. This one at Summit looks like it will fit as I only have 3.25" clearance between fan and pulley studs. It's 4k cfm. Good or no good?
http://www.summitracing.com/parts/DER-16934/

Not running underdrive pulleys.

He did tell me he was on the phone with the Summit technicians almost daily.

Water pump is not aluminum. I was going from memory and I guess it failed me. Could have sworn it was aluminum.

It does work that way.

I will do that, wasn't sure if I should run it without the cap.

My driveway is steep and the radiator was at the highest point. I think it was just air bleeding out of the system. I don't believe it does it normally, just after changing the fluid but I will check. The stat is 13 pounds. I will get a tester and check the rad pressure and cap pressure.

The 1st pic is what I think may be an air bleed for the coolant.

prossi

why not just buy a cowl induction hood?

taonindo

a cowl hood pulls (cool) air in not heat out....

1988GTA500HP

I have a 3" one now, still hot. I ordered a 4" but was told it would be a couple of weeks before he can make it.

1988GTA500HP

A couple of more pics.

customblackbird

iTrader: (15)

Yes, that is the right switch and stat. They should be coupled together. I think i have that same switch if you wanted to save a little money.

That fan setup looks pretty good. Im not totally sure on the fan output but the shroud and dual fans will be pushing ALOT more air than your current weak fan. SHould be enough for your application. Thats actually a nice setup, looks like it has the high pressure flaps as well and is a decent price.

this is what Im currently running http://www.ebay.com/itm/New-Radiator...768#vi-content its a dual fan setup with integrated shroud, i cut some flaps in it for the high pressure issue. These fans I think are 13" as well and i got mine off amazon for roughly 120$ and they pull a good amount of air and i think they are only 2.5-2.75" thick. I had less than 3" of clearance so i had a little trimming to do.

The pump still shouldn't be an issue. And why are you running a 13lb cap? get a 16 lb cap from summit as they are cheap and you should see some benefit from that. The 13lb is NOT enough and thats prob part of your problem esp when the engine temp is getting as hot as it is.Not sure about that bolt/bleed in the intake. does it connect into the cooling part in the intake? should be fine leaving as is bc if the rad cap is the highest point then all air should go to it.

customblackbird

iTrader: (15)

I can see an issue with that upper rad hose. Take the time to get an original replacement water neck or something that puts the hose straight out and then look into getting a stock pre molded hose. That hose is way to high and is higher than the rad cap, air can get trapped in there and cause all kinda of issues.

1988GTA500HP

Great! I will order those. Thanks.

Appreciate the offer but you have helped out enough already.

Comes with the harness and dual relays. Seems like a good deal.

Doesn't list the dimensions which always scares the crap out of me. Not sure it would fit. Is it a through-the-radiator mount?

That is what was on there. I assumed they knew what they were doing but it is becoming obvious they didn't.

1988GTA500HP

Holy crap! Thanks for that tip! I'm not sure what the stock hose should look like. I found a pic in post #9 of this thread but it looks like the hose goes over the alternator. That would put it higher than the radiator cap. Is that the right setup and water neck?

https://www.thirdgen.org/forums/cool...elocation.html

Summit shows 4 different ones for 1988: 20", 22", 26", and 28", DAC-71203, GTR-61243, GTR-62160, and GTR-61331 respectively.

1988GTA500HP

Hard to tell but it sure looks like the forward facing alan-head plug does.

1988GTA500HP

I took it for a 25 mile ride today. First starting out it hung around 160 for a while, maybe 3 or 4 miles. Then it slowly climbed to 180 and I manually turned on the fan for the rest of the trip. Cruising around slow in the 40 mph range it hung at 180. When speed picked up it would drop back to 160. When sitting in traffic for long red lights it got up to 210 but would drop to 180 when I got going again. Never went above 210 with the fan manually on. I am pretty sure you're right on about the fan being underpowered for a 400, which as I understand are notorious for running hot. I'm thinking the fans, stat, coolant switch, water neck, rad cap, and molded hose will solve the problem. We will see. Thanks again for sharing your knowledge.

customblackbird

iTrader: (15)

Get what suits you, if I had the cash i would do with the Derale unit. But also make sure that you have enough room for it, it states a 3.25" depth, make sure you have at LEAST that amount. otherwise keep looking for lower profile setups.

customblackbird

iTrader: (15)

hard to say, my only experience with 3rd gens is the TPI kind, my 87 and my dads 86 that I've worked on and bought parts for. I know the TPI hose is different than that.If you got the TPI hose and a swivel neck you could be golden.

this isn't my motor, my pics are on another computer. But this is wat the hose looks like its very low profile http://www.motortopia.com/files/110/...f/DSC_0020.jpg

check out this thread, post 10 and 20 but there are a few pics of different setups for ideas https://www.thirdgen.org/forums/ltx-...ur-engine.html

customblackbird

iTrader: (15)

sounds like fans to me, could also be helped with a higher flow water pump. I think you know what you need to do, hopefully it will run much better!

1988GTA500HP

That's what it looks like. That is the best way I could see to run the hose. Looks like this is the correct one.
http://www.summitracing.com/parts/GTR-61331/


Those are tight. Looking forward to getting there. I am def going to get the swivel neck since the stock one doesn't look like it is at the best angle for low profile. I will post pics of my progress. Now thinking about going with your fan setup. I can fab brackets. Should I remeasure my radiator and include the area outside the core? What did you attach your brackets to on the radiator side?

customblackbird

iTrader: (15)

this hose looks correct but its hard to tell. go to a auto zone or something and see what they have in stock that way you can return it easier.

this hose looks like my OEM one http://www.summitracing.com/parts/DAC-71203/

I like these bc they are really good, you can bend it the way you want it but it won't retain the shape you want, its just flexible http://www.summitracing.com/parts/GTR-52023/ if you were to order from summit, get this one as a backup, thats what I would do incase the one you get doesn't work.

that one you linked looks longer but if you can trim it, it might work.

What ever you do make sure you get the right hose with the right end sizes. I forget what stock is, either 1 1/4 or 1 1/2" at the rad top and I thought the water neck is 1 1/2"?

Here are a couple of pics of the charger cooling fan on my rad. You attach the brackets to the top and bottom lips of the radiator. Don't put it into the side tanks bc that will leak. Mine fit right into the core with a little trimming to the shroud. You don't want the fan/shroud on the outside of the core bc it will be farther off the core surface. you want the core to meet right up against the shroud bc it will allow most of the air to be pulled through the rad. IF the shroud is off the surface of the core it will pull air from the least restrictive area, which would be that space between the core and the shroud. Basically pull air from the open space instead of pulling it through the radiator.

this is my 521 BBF in my 87 firebird. it looks a little different now with new distributer and spark plug wires. but the fan setup is the same.

customblackbird

iTrader: (15)

here it is now its massive and u can see from the pics in the last post how close the rad is to the water pump pulley etc. The chrome container on the upper hose (pass side) is a "swirl pot" I needed a fill point that was higher than the water neck bc my rad cap is about 1.5" lower than my water neck, the BBF is that big. I kept getting air caught in the upper part of the motor bc I couldn't bleed the air out. The info that I've been giving you has been a lot of trial and error and massive amounts of research and questions that have been answered by other forums/guys. But in the end I'm more knowledgable than most in cooling systems lol.

1988GTA500HP

Very nice! Looks like you needed a shoe horn to get that bb in there...lol. You weren't kidding about the clearance issue on the fans. Motor looks great. Do you drag it? If so, what times it run?

1988GTA500HP

Very clean. Nice install. You definitely know cooling systems. I know way more now than I did, but nothing close to you. This is a great forum for learning things about our cars. I never even heard of a swirl pot but make sense with that monster stick up. Guess it would be too hard to fill while in a wheel stand.

1988GTA500HP

Actually, it looks like this one was designed to completely cover the core of our radiators.

http://www.summitracing.com/parts/DER-16826/

Then it becomes a matter of how to control them since each draws 25 amps. They recommend you don't let them come on at the same time because of the draw on your battery. I am running my current fan off the factory relay. I have a spare factory relay that used to control the second stock fan. I could add another coolant switch in my intake with a 195 off/205 on if I can find one. Or maybe I could use the one I got that's 204-220. Do you know if the factory relays can handle 25 amps?

Of course, there's always this.

http://www.summitracing.com/parts/DER-16789/

customblackbird

iTrader: (15)

yea I can only install the fan/shroud from under the car, which means I need to jack it up pretty high to get it in and out lol. Yea i have no clearance, this was after pushing the rad closer to the bumper and lowering to 1.5" to clear the block and hood.

Yea I've had it out once this year so far, ran a 12.2 at 114mph with a 1.8 60' on 295 MT drag radials. I couldn't get it to rev higher than 5000 bc I think i was getting valve float. My 60' should be in the 1.6s but the car isn't setup up for drag racing and I would blow the tires at the line/20' out if I hit the throttle too much. its got way too much low end grunt. I have to leave off idle and baby it for a little then WOT it for the tires not to spin. It should be a very low 11s/high 10s car on the motor, but its got a 100-250NOS plate kit for a little extra umpth! lol

and thanks for the kind words. She's a beast!

customblackbird

iTrader: (15)

Swirl pots are common in europe and there insane sports cars. They swirl the liquid which constantly aerates the fluid and has other benefits. I can't actually see if its working bc the pressure from the cooling system would shoot a gyser out and kill me with hot coolant. They are common on cooling systems and fuel systems on imports etc.

customblackbird

iTrader: (15)

man these shrouds just keep getting more expensive huh lol. My kit that Ive got is from derale and it was much cheaper than that, and its adjustable from 100-250 i think and came with a screw in port sensor.

Whats weird is that the shroud u just posted has dual 14" fans and is rated at 4000cfm, but the first one you posted had dual 13" fans but it was rated at 4000cfm, the only difference between the 2 is the 14" fans have a 11 blade design and the 13" fans have a 10 blade design. Again take all the CFM ratings with a grain of salt as more than likely they don't actually flow what they say they do.

I saw that it said 25 amps but it doesn't say for each, thats a lot of current for each motor. I think its saying 25 amps for both at running speed. Remember that it will pull considerably more amps on startup. Mine was like 32 amps at startup and only 19 running. I have no idea bout the factory stuff, but look at the fuse that will tell you what they can handle.

What i would do is get an adjustable cooling fan relay setup and use that to control one of the fans. Then use the stock one to control the other. You can have them come in at separate times so pull on the batt is less. Say you get the Jet fan switch 200 on and 180 off, have that control the one fan. THen use the adjustable fan relay to have the other one come on at say 180 and off a 160 or something. That way if you get above 180 your second fan kicks on and save your @SS lol. Honestly you don't have to worry about them kicking on at once unless your charging system is adequate in the first place. I both mine are wired to a relay for a single fan setup and they come on at the same time. my charging system is just a single wire 95amp alternator and a 1000ca/800cca duralast gold batt. Im not running AC, blower motors, radio anymore but I got more gauges than an aircraft and high power racing ignition and meth injection pumps as well as dual fuel pumps and dual HID projector setup. You just need to add up all your amps that your using and hope your charging can keep up.

customblackbird

iTrader: (15)

heres one thats only 45$
http://www.summitracing.com/parts/SUM-890015/

this is an adjustable one and looks like mine kinda, prob a newer version of mine 44$
http://www.summitracing.com/parts/DER-16749/

DOnt get a probe setup get the one with a screw in NPT sensor. just make sure you have a spot for it in the coolant stream in the Intake.

1988GTA500HP

12.2 is pretty good for the quarter. I was thinking it would be high 12s cuz our cars aren't light, and neither is that beast of a motor you got squeezed in there.

1988GTA500HP

Doesn't seem like the probe one would be accurate enough since it's in the radiator and not the block, plus it has air blowing around it. I think the first pic I posted for the possible airbleed has a spot for a switch, where the alan head plug is. Looks like it is in the same tunnel as the temp guage sensor.

I like the second one for 44 bucks. Being adjustable, could you use it to compensate for seasons? Or is it too involved with the rest of the cooling system to screw with it.

customblackbird

iTrader: (15)

Sorry been busy working on the car. No is pretty easy, just turn the small adjustment screw with very small flat head screwdriver and your good. Only problem is that you can't tell what temp its coming on unless you adjust and check the gauge and hear when the fans come on but theres no sure way to tell when its coming on bc the screw doesn't have a way of telling you.

You can adjust it day by day, say u like it coming on a little hotter in the winter for heat, then adjust, summer you want it on a little cooler then adjust. or if your going to have a very hot day like today in NJ then have it come on earlier. DOesnt matter too much tho bc the Tstat will control when the fluid is moving unless you run a restrictor like me.

I actually took my car out today for the first time in over a month and a half and it was stupid hot out today, i wanna say 95*F in the shade and it was sunny and HUMID! around town my engine got to 190-195*F city driving below 40mph lots of stop and go. Took it to the highway and a few pulls to 5500 on a steep uphill grade for a min or 2 and temp got to 205*F which is the hottest its ever gotten too and freaked me out a little.

let us know how it works out!

1988GTA500HP

It says on the website that one revolution of the screw is ~2-1/2 degrees. I am going to hook up my fan toggle and LED to the secondary fan, so I can turn it on earlier if needed. Therefore, I will be able to tell what temp it comes on in the cockpit because unless these things are incredibly loud, I would never hear them turn on.

I have most of the stuff for the upgrade, just waiting on the shroud. I'll keep you posted.

customblackbird

iTrader: (15)

I can tell you that with mine which is the same part# only has 3/4-1 turn of adjustment on the screw... so like a 1/4 of a turn of the adjustment screw is like 40*. thats why its so hard to set to a specific temp.