S_Johnson

Ok, so I have a 400SBC with a carb. Setup is as follows...

Holley carb...

HEI Distro/Ignition, "normal" timing, don't remember exactly, done by speed shop, who new I wasn't racing, I think he set it at 32*. With NO vacuem advance...

dual plane "air-gap" intake manifold...

GM 487x heads 76CC, with 2.02 1.6 valves, and minor "street" porting around valve stems...

moderate-ish cam, I think it's 224 234 duration at 5, and 480's ish lift. sounds pretty radical...

400 bored .03 over, with speed-pro's dished for 9.0-1 ratio.

shorty headers with heat-wrap...

NO smog-or AC, just alternator water pump, and power-steering...

stock water pump and radiator...

160* thermostat

Hayden fan, It was the biggest one they sold at shuck's, I think it was 14" or something, it seems to move ALOT of air through...

no shroud


My car did fine in washington state, even in town, it would rise to about 220* at the MOST, then go back down once the fan could really dig in.

Now, in NC it's about 95 or so, and it overheats CONSTANTLY, it stays 220 or above, sometimes up to 245-250, unless I'm on the freeway, then it goes down to 180ish, although, it USED to run at about 159 back home on the freeway.

My thought is, will a bigger rad help? I have a line on a 3 core circle-track radiator from craigslist, all aluminum, preassure tested etc... but will that just make my fan less effective? SO confused...

OH, and I KNOW it likes UNDER 220, beacause it has a tendancy to diesel for a second after shutdown if it's up to 220, even on 92-93 octane gas, and it's seems to perform better at 160-180 as well.

also, I have a HUGE aftermarket tranny cooler in front as well.

Thanks Guys...

Awesome-X

Fan shroud would be my guess

camaronewbie

Still running stock fan switch in the head? If so, get a seperate adjustable fan controller - they are great! I have a Flex-a-lite, it's fully adjustable, probes radiator instead of the head, has provisions for everything including manual on/off toggles. I've had it 4+ years now on a hot-running 350, and with a 180 stat I never get above 210 even with these 100+ temps we've been having. You can leave the stock switch in the head as a plug. Easy to wire, I highly recommend!

Where in NC? I'm in Raleigh area.

elano

iTrader: (2)

Definately fan. Get an aftermarket switch that mounts in the radiator and turns it on around 200 and off at 180. Also a better fan with shroud might be needed. I picked up my ford tarus fan from a junkyard for $17 bucks and it's the $h*t!!! Make sure it's the one with 3 wires comming from it, the're out of mid 90s ford tauruses.

Awesome-X

Yeah I just put dual E fans on mine and ran them to a switch. They cool alot better than the stock fan but I'd like to get a nice adjustable temp switch, where can I get one camaronewbie?

S_Johnson

I already have a "custom stat relay kit thingy" it probes the rad, the fan is pretty much on ALL the time.

I'm in the thomasville area (greensboro) Camaronewbie

camaronewbie

This is the one I have - there's other brands, some with more some with less bells & whistles - it's expensive at $100, but it's the best $100 I've spent!

http://www.summitracing.com/parts/FLX-31165/

It's been record heat here, I have a 180 stat, and have it set so fans come on about 190 - but it's nice 'cause when the weather cools down, it takes 30 seconds to readjust the fans to a higher temp. It was 102 the other day, I never saw over 210 on my guage even in stop/go traffic, and I'm just running stock radiator and single stock fan.

S_Johnson Welcome to NC!

naf

iTrader: (7)

Check your timing. Is it locked at 32 or mechanical advance only up to 32? If it's mechanical advance only, a dist with vacuum advance will run cooler and more efficiently, especially at idle and light cruise where the rpm's are low.

Make sure you have a good tune on the carburetor? Changes in elevation can affect your mixture, if you were substantially higher in Washington.

I would make sure the motor's producing as little heat as possible - timing/tune - way before looking for new ways to transfer that heat. An efficient motor produces as little heat as possible for the power out the back end.

irocman79

iTrader: (5)

this mighy not help but do you still have all the factory air ducting installed the directs air to radiator and the air deflector the bolts under radiator. if removed this stuff especialy the air deflector it makes a big difference even in town. it did on my car

Sonix

iTrader: (1)

A 400cid running without load (through town), should be making much heat. Under heavy load you might need a big fan or rad, but under low load a 4cyl rad and fan would keep it cool.

the 487X heads are 350 CID heads? Were the steam holes drilled? 400cid head gaskets? You might have been marginal before, and are now over the line. I'd make sure those are done.

Is the thermostat going wide open by those temps? ie, have you pulled the t-stat to check to see if the situation changes?


I also have a fan from a early '90s Ford Taurus, 3.8L. Those are AWESOME. I run mine on low, it's a two speed. I don't even need to run the higher speed.

Naf is right though - Timing is a big one. Make sure you're not running right at stoich at cruise, and having vacuum advance at cruise (~46* timing) helps keep the engine cooler.

1989GTATransAm

iTrader: (3)

"Hayden fan, It was the biggest one they sold at shuck's, I think it was 14" or something, it seems to move ALOT of air through...

no shroud"

I agree with the above posts. That is your problem. I have heard good things about the Ford Taurus fan as posted by Sonix. A lot of people are using them and they are cheap. Also the Lincoln Mark VIII fan if you can fit it in.

elano

iTrader: (2)

I got my radiator temp switch from advanced auto for $20. I have it wired to the low speed on my taurus fan. The high speed is wired to a switch I put in the dash so I can hit it if things start getting too warm.

S_Johnson

Ok, on the thermostat for the fan issue:
I bought this kit from schuck's, it was like $20 and I THINK only has one "speed" on it, you just turn up the little dial until it turns on when you want it to...

Mixture:
I've ALWAYS been fiddling with the Carb, I have a narrow-band O2 and gauge hooked up, and it SEEMS to be fairly accurate-ish... and it seems to think it's lean at idle, but I've been told a narrow band will be WAY off at idle with that cam... So I don't know, it seems to idle well...

Timing:
I don't know how to discribe the distro, except that it's "standard aftermaket chevy HEI" it's billet, and shiny, and Red... lol ... it HAS vacuem advance, I just have a vacuem plug over the port on the distro, and carb.

Heads:
I already new about the steam holes thing (biggest joke on the net about 400's... ) and had them drilled, I have no idea what those heads were for, but from the sound of it they were a performance GM casting, probably for vette or something? so probably 350.
And yeah, 400 head gasket, it had to be, nothing else has a bore over 4 inches...

No, I havn't removed the t-stat, I'm heasitant to do that, as the stupid cheapo "chrome" water neck BENDS everytime you tighten it down, until it leaks and doesn't fit anymore, and I have to get a new one! argh...

Trimings...:
Yeah, to my knowledge I have all the stock "air dam" stuff, I know I at least have the bottom dam, and besides, it's not overheating on the road, it's overheating at idle, and low-speed in town cruising.

Thanks a bunch guys!

S_Johnson

just had another thought, my exhaust is actually kinda ristrictive for this motor, crappy shorty headers with 1 1/2 primary's, into a dual exhaust, compression bent, that looks like a grease trap in a couple of places right off the headers, would that influence things? I mean, I don't THINK it should, but you never know...

naf

iTrader: (7)

Connect your vacuum advance. You'll get better mileage, driveability and your motor will run more efficiently and cooler.

S_Johnson

Ok,I'll try that today, although, I'm not sure where to connect it. Don't you plug it into "top" vacuem on the side of the metering block? (holley carb) and it will idle faster(smoother) if it's right, correct? Thanks guys, advance is like, black magic to me, I've never really got it Thanks again...

camaronewbie

You won't notice any change at idle when vacuum attached to dist - it's usually connected to a ported vacuum source so there's very little if any vacuum at idle - the vacuum advance kicks in under throttle.

S_Johnson

ported vacuem? not sure what that means...

camaronewbie

Usually two vacuum sources on a carb, usually one is ported and one is manifold. The manifold vacuum has vacuum all the time, the ported one is opened internally by the carb. Usually dist are connected to the ported vaccum source so that timing is not advanced at idle where it doesn't need to be. If advance is needed at idle, base timing can be changed to accmodate.

S_Johnson

gotcha, a hooked it up, let the engine heat up, and drove around the block a couple of times, and it doesn't seem to make any difference, in fact, if anything, the motor seems to be putting out less, kinda like when it was detinating really bad on me, it just didn't do much, because it was basically deiseling every compression stroke... kinda makes me nervous...

grover85

iTrader: (1)

I had a vary similar set up and same problem as you.
First. What is your ignition timing at?
Second. The fan you have is junk. I don't know if its lack of flow or shroud but those fans from checker never worked for me. Put in stock dual fans and it cools no problem.
Third. Maybe try a hotter stat? I have a 180 degree in mine and have no problems. Possible the stat opens too soon and coolant flows to fast through the radiator?

camaronewbie

A HOTTER stat is going to make the engine COOLER?

I'm lost on that logic

naf

iTrader: (7)

If the vac advance caused driveablity issues it's another symptom that your timing needs some attention. What else changed since Washington?

S_Johnson

nothing else changed, and the thing is, it's not overheating now, the temp is 82-90ish here the last few days, and I've had no problems, I think my fan is just pretty crappy I'm going to see if I can find a taurus fan, since you guys seem to like those . Also, the fact that it isn't shrouded, means, even if it's pulling alot of air through, it's only pulling it from the middle circle of the rad, I think a shroud, or 2 smaller fans, would grab a larger AREA. thing is, other than this overheating thing, the car is pretty good. the only mixture problems I seem to be having is that the accel pump on the holley is SADLY deficient for the 400. even fully warmed up, it has a nasty hesitation when you first stomp on it. It's almost like a bogged down feeling, but I don't think it's the secondaries opening to soon (I mean, it's a 400CI engine with only a 670CFM Carb) and it's too soon I think, it HAS to be the accel pump when it's an INSTANT bog, that recovers quickly. Any advice would be much appreciated...

RED86Z28

Mine has similar problems until I removed the 14" fan and installed stock type ones.
On your carb you can try changing the accelerator pump cams and squirters. They are cheap and easy to swap.

S_Johnson

cool, thanks. One other question about the carb. to use the "50CC" instead of "30CC" pump diaphram, do I need a different accel pump housing itself? Thanks...

Enzo1989

Just wanting to know, do you have aftermarket heads? They need steam holes drilled for a 400. Also a shroud would help with dual fans, even a bigger radiator maybe.

regal301

dont connect the vac. advance to a ported supply.

find a constant vac. source.

take the cap and rotor off and check the weights and springs.make sure its free. and check the vac. advance diaphram to make sure it pulls under vac.

if the advance is working you WILL notice a difference in the idle and off idle acceleration.

set your timing with the advance disconnected.
-------------------------------------------------------------
also there was an issue with swapping heads on the 400
-------------------------------------------------------------
and your driveability issue sounds like a lean condition
and that will build up heat

regal301

a few other ideas that helped cool down my friends 67 buick riv. the size of the waterpump pulley (got a smaller one from a a/c car) will affect flow,and water wetter from redline that stuff works good.

flexxedout88

I have the same setup in my car a 400sbc with th350. It's mildly built. Mine is over heating as well... Pretty much what u described. I have a bigger cam and aluminum heads and about a 10.5:1 comp ratio. And my car will idle allday and never over heat... But when I drive it is when it does... I had a factory single fan and I ditched it for dual Hayden one 14in and one 12in togather pullin about 2000 cfm at max. Still the same I has a new radiator water pump 160 tstat my timing Is 32derees everything is as it should and I have been battling this since I put the car togather a few months ago... I talks to a friend at the Machine shop and he told me somethig that kinda made some sense. The 400ci block is diff. From a 350 block at it does not have coolant passages between cylenders there for it runs hotter making the cooling system have to work harder to disperse the heat.... I'm gonna run a larger radiator and see if that fixes my problem... I'm gonna try and find a low buck swap so I don't gotta drop 350 or 400 on a radiator... Does that sound right to any1?

flexxedout88

no input any1 have any input.

tkcaraudio

In my car I have a Jegs 4 Core Aluminum radiator a be cool thermostat that kicks fan on @ 180 degrees Stock Water Pump and Stock Fan even in good guys car show traffic for 3 hours last week at 90 degree weather I didnt get over 205-210 degrees in ohio

I would make sure they water holes was drilled in your heads to match the 400 block and make sure they used the 400 head gaskets also

fireburdluvr85

i have to agree. if you don't have the steam holes drilled you will overheat. maybe not at idle but def when driving it. last yr when i had my 400 i didn't know anything about the steam holes till i did some research on the net and found everything i ever wanted to know. i also had a dual fan set up with the 180 stat with smaller pulley on the water pump. its all alil extra insurance to be honest.

S_Johnson

cool, thanks guys, I'm going to try and dig up a timing light somewhere (I'm unemployed right now, so I can't really buy one... ) and go through the whole "non-computer controlled HEI Setup for performance..." article in the tech section, and really get my timing right.

Plus, I just picked up a dual fan setup from a 4th gen at the wrecking yard for $35, so that should make a BIG difference at idle etc...

jag327

I went with a mark 8 fan if you go with this set up you have to run a 140 amp alternator and up date your wiring. I'm running 327 small block. I had over heating problems to running up to 235. The funny thing with the hood up motor running about 3500 rpm temp would stay 165. Under my hood I check the temp when the car was running for 10mins it was reading 220 so I'm adding open scoop to let some of the heat out and may do louvers 1 trip on each side over the headers. My other car with a 372 mopar motor in it has room buy the header open to let the heat out on the lower front sides panels.

I do have 2 extra fan shroud set ups made for the fbody type cars.
If you need one let me no.

[IMG][/IMG]

S_Johnson

just for morbid curiosity, how much would you want for one of those setups? how big are the fans? Thanks

jag327

Fan shroud size is 25"1/4 wide x 18"1/4 tall x 3" deep should fit min other radiators with 2
1550 cfm fans total 3100 cfm flow I had 4 all together sold 2 of them to friends. I'm keeping 1 set. The machine shop was taking to long to make them so on I went and pick up Lincoln mark 8 fan - these fans pull some high amps on start up I had to up date my alternator to a 140 amps change the wiring from the alternator to 6 gauge wire up date my main wiring going to the dash and add to relays for the high and low speed. When the new fan shrouds got finish I pull the mark 8 fan out to make sure they cool the motor it works.

This a pic of the fan relay for a mark 8 fan I used

[IMG][/IMG]

pic of the fan temp control and wiring

[IMG][/IMG]


The fan shroud I will take $160.00 for it with the fans

naf

iTrader: (7)

Were you starting both fans at the same time? There is also a progressive fan controller that can soft start them for less current draw at start up. I can not, however, find the thread that discusses this...

jag327

It's the relays in my picture. The fan shroud set up can be install with out relays

camaronewbie

I understand the unemployed - same here!

Don't know what shipping costs are, but Harbor Freight sells a fine timing light for $15.99

http://www.harborfreight.com/automot...ight-3343.html

one92rs

iTrader: (5)

the flexalite controller does a type of soft start.

S_Johnson

OK, it seems to be working great except for one thing, my "controller" is turning the fans on at random times after I turn the motor off, sometimes like, 1 hour later...???

S_Johnson

oh, and thanks man! Good Luck!

one92rs

iTrader: (5)

what controller are you using.

S_Johnson

No idea... Some generic thing I got from Shuck's... probably Hayden? since that's the brand of cooling stuff they carry???...

one92rs

iTrader: (5)

there should be an ignition wire going to it that will turn it off with the car.

S_Johnson

Ok guys, Update time...

I've solved my "in town" issues by installing a 4th-Gen dual fan setup (with shroud...). It works great, the fans move MUCH more air than my single hayden did. I still have one problem though, my fan switch is EXTREMELY unreliable. Not only does it turn them on HOURS after the car is off (I can fix this by making it conditional to the car being on I know...), but it also doesn't turn them on consistantly. Sometimes it lets it get to 210 before turning on, other times, they turn on at like, 165!!!! It's REALLY annoying me.

I think one of my problems is that my switch uses a little metal "probe" that sticks through the rad, but only like, 1/5th of it actually is in the radiator (because it's only an inch thick rad, stock...). I want a setup that uses the stock sensor that's in the tank of the rad itself, That's going to get me the most consistant/accurate reading right?

So what do people recomend for getting this to work like it's supposed to? The keys would be simple, and cheap (still unemployed ... ).

Thank again.

//<86TA>\\

iTrader: (14)

there is no sensor in the radiator for the fans, its in the head, where it should be.

af for adding on in the radiator, you would have to have a bung welded to the radiator (if its aluminum), or use another hole in it if there is one and you can use it. There is usually a heater outlet at the top by the upperhose, but its not normal a threaded hole. Im sure you could rig something together to fit there, but its not the best idea.

S_Johnson

OK, So, using the temp guage in the head (mine is functional and everything, my temp guage works), How should I set this up?

I'm really bored with it's flakyness, and I think it's because of where the sensor is located, and how badly it's mounted. It's getting a reading on the temp of the rad, NOT the engine, and it's only getting the temp from one small PART of the rad, I mean, waterflow isn't perfectly even, so even if the switch itself was PERFECT, the whole basic concept is flawed right?

Thanks again.

naf

iTrader: (7)

The stock location for a fan switch was in the pass side head. The driver's side head has the sender for the dash temp guage. The stock switches turn on kinda high for most people but as long as the radiator is not boiling over, it's really NOT overheating.

An alternate location for a temp switch besides the head is the manifold or the water neck. The ECM took temps at the water neck with a two wire sensor. The radiator has a bung for a sensor. It was used in the Berli for a low coolant level sensor. Don't know if it's possible to install a temp guage there but I'd prefer reading temps at the engine.