400 sbc and electric fan help needed

[greg64]

Sev, one other improvement you can make is to take the voltage sense wire from the alternator, and run it to your new terminal strip. The benefit of this is that any loss in the wire from the alternator to the power strip will be compensated for by the regulator. So, you could end up with 15.4V at the alt, and 14.4V at the terminal strip.

I did this on both my trucks and it works, and charges great.

[sev85]

man that is a really clean install i like it

[sev85]

really? now that is a good idea greg im definitely going to be doing that

[greg64]

Well, I brought that up because some guys just loop the voltage sense wire back to the output terminal on the alt. this is also what 1-wire alternators do, which is unfortunate, because they give up a good capability. In fact, the factory used the 3 wire configuration because it allowed them to use cheaper (smaller) wire, because the loss was being accounted for. I think Novak-adapt has a good write up on this if you want to learn more.

What I did was to run a heavy wire from the alt to my power distribution block at the firewall (not a stock piece). At that point I also mounted a bunch of circuit breakers that feed different parts of the truck (one being the original fuse block). I also have a small wire that goes from the voltage sense on the alt to the power block.

[sev85]

greg i need to thank you i just read a article on novak-adapt about cooling and learned more from that one article than i have in 20 years of helping work on cars and working on em as well as the common myths with cooling systems

i realize now my issue is not in the flow or how much i upgrade my cooling system as it is my lack of airflow to disperse the heat in my cooling system and how to much flow can be counter productive to the dispersal of heat as well as how little upgrading to a thick 4 core radiator and a cooler thermostat reduces dispersing heat its not the thickness of the core but yet the area and length of the core to spread the heat on to disperse the heat from as well as efficient air flow thru the core to remove the heat off of the core

also my ethylene glycol mix maybe to high and being counter productive in my cooling as i learned pure water is a better heat carrying compound to carry the heat off the motor to the radiator as my ratio is probably 70-75% ethylene glycol mix where realistically for my area here in ks i only need a 50/50 mix so protecting my radiator down to -45 is a bit drastic when i should be more concerned with about -20 at the 50/50 mix

also going to look into the amount of pressure im running to make sure im utilizing my boil points

and i also learned the importance of properly tuned operating temperatures and the importance to the right operating temperature to efficiently burn fuel and burrn off carbons

i have not gotten to the wiring write up yet but i will be looking into it as soon as i find it

sorry for the book but learned alot in reading that 20 minute article

[sev85]

i do also wanna add a thank you to everyone else who has commented on my thread with input and advice as i have learned a lot of the littler details that add up into a big problem when the little details are not correct

[Bigstevex4]

Originally Posted by sev85

Has to because a belt driven water pump is always pumping the minute the motor is turning over

They just block the flow .But if heater hose does return to rad. then your getting flow through rad.even with stat closed start it up cold the upper hose should stay cold then when reaches stat temp it will get hot fast. if it graduly warms up thermostats not fully closing. they open close faster than think.

[sev85]

they can open fairly quickly but its not like flipping a light switch quick steve i boiled 2 of em just the other day and the stat is closing fully the one in it is brand new boiled it before i stuck it in

either way i figured out the problem on the truck

[piecesparts]

A standard T/stat is designed to open at a set temp and then maintain that temp by opening and closing. The Superstat, that many companies make is designed to open at a set temp and the modulate in the middle keeping the flow moving in the core. The difference is the standard is either full open or closed and the Superstat modulates.

More of the trucks with electric fans installed. The first two are on a 91 Silverado and the third one is my 84 GMC.

[sev85]

gorgeous installs man

i am still working on the wiring for mine i made a harness with a plug on it so if i ever need to pull the fans there is a 4 pin plug that is mount to the core support so the fans unplug and can be pulled off unfortunately had more dr appointments about my injured arm for my car wreck and we keep having fairly cold days so progress is moving quite slowly

what are your guys thoughts on the electric fan controllers versus the screw in electric fan switches i keep seeing a ton of bad reviews on the electric controllers specificly the hayden model going out in less than a year even ran to a relay

[piecesparts]

I am running the SPAL electronic fan controllers, BUT they are no longer available, so there must have been some issue with sales on the units. They were priced fairly high. There are several brands on the market and they should stand up to normal use.

[greg64]

Sev, glad you read the Novak article. I'm not a jeep guy, but I came across the Novak guys probably 10 years ago. I've read every tech article they have, and I agree with them (not like I'm some kind of authority or anything).

As for fan controllers, I'm not much help. I keep wanting to build my own that does PWM, but my wife has me working on house projects. One thing I can tell you, in my suburban, I have a dash led that comes on when the fans are actually running. That's really useful when you've got a close eye on the temp gauge.

[sev85]

Greg I'm not a jeep guy either but yeah that novak article was amazing i had no idea they spent so much money in R&D just to figure out how to get the gm power plants into the jeeps and they talked about how reliable and simple the gm motors are to setup and make run properly again one of many reasons i love gm and i was rally surprised to see how many myths i grew up with about cooling a motor

yeah i am definitely going to do some sort of led for when they are running but i just keep seeing problems with the electric controllers so i may run to oreilly or autozone today and pick up a electric fan switch that screws into the side of the head (for 4.99 i know its cheap but that ironically is the most expensive one they sell) and see what that does for me today

i got the wiring harness made for the fans i got more junction strips tied into my battery now and all that is left is to do my alternator mods and some mods on my factory harness that we discussed previously and wire up my relay box once i test the screw in fan switch and it will finally be complete minus some sheet metal work im gonna do as covers for my junction strips and the new harness im gonna make

[greg64]

I've just got a cheap fan switch on my 77. It's simple and it works. Of course, the fan switch actually triggers a relay that powers the fans, I don't have the full fan current going through the fan temp switch.

[sev85]

hey guys i picked this little fella up today in the junkyard off a saab I dont really know what its called or its name but the little guy regulates the voltages to give high speed and low speed on single wire fans i am wondering how i can incorporate this in my wiring to give myself hi/lo speeds easier than building a special harness and multiple switches



also here are the pics of the wiring harness and the wiring harness installed to the fans, still gotta get a switch of some sort and the relay box installed just to cold out lately with my injured arm to really be able to do much





I also picked up some factory radiator mounts for my truck today gonna try and see what i can do about adding a mount onto them for the electric fans for a more stock and cleaner look

[sev85]

also greg on your switch is it a electric fan controller or a electric fan switch that screws into the head or intake of the truck to get its temp readings?

and where did you get it or is it off another make and model of vehicle if so which one?

i canceled my order on the hayden electric fan controller i have seen and talked to alot of people who have had considerable problems with them going out in like a week sometimes a year

[greg64]

Sev, I just have a fan switch. It's a mopar part, if I remember correctly. What I did was went through the paper catalog at my local parts place, until I found a switch that had the on/off temperatures I was looking for. The only mistake I made was that the switch has a wacko metric thread on it. What I did was build a custom tee fitting that is inserted in the heater core supply line, so the coolant circulates past the sensor all the time.

[sev85]

hmmmm never thought about that.... the reason i ask is i have hit probably a dozen parts stores looking for a switch that works in the operating range i want of 180-200 but i would really like mine to screw into the head port thats plugged off i know its a 3/8 npt thread i just dont want to go with a cheapo off ebay because im afraid of the consequences and the reviews are horrible even for the summit switches so i was hoping to find a oem switch out of like a newer monte carlo v8 or a newer camaro or something with a one wire blade connector to screw into the head i can always get a adapter but i cant find one in the operating range i want

[greg64]

I hear ya. I had the same problem finding a switch. You might want to try rockauto.com, because you can lookup all sorts of vehicles for something oem.

[gmachinz]

I would just run a 212/202 switch in the intake or t-stat and run another switch 228/218 on/off in the same area or go with a 238/228 in the cylinder head. This will provide you with a 190-195 constant operating temperature once the thermostat has opened.

[gmachinz]

Also, unless you buy a $35+ Summit Racing or Hypertech 185 switch, you won't find an OEM one because with the days of EFI and electric fans, the best mileage AND performance is an engine running at 195-200 degrees so OEM don't offer much in the way of fan switches below 200 degrees. Besides, why go any lower? You'd want the radiator to shed heat before requiring the fan to come on anyway. If you need a stout fan harness, PM me for info.

[jjzepplin]

My 406 also runs an Air Gap and dual fans. I also run cooling hard lines to the rear ports on the intake which supposedly forces water to the back of the block. If I remember right the fans are Flexalite and I run the adjustable thermostat. I also have a high flow thermostat in the thermostat housing. I have a 4 core stock radiator and those corrugated metal upper and lower cooling hoses. Been that way for quite some time and never overheated. Not even in the mountains. Both fans come on at the same time. No bigge. Only relays are the one that comes with the setup and one to disable it when the truck shuts off.

[sev85]

hey jj you dont have any issues with the fans running the battery dead? how big is your alternator?

[jjzepplin]

I do have a 140 amp alt. and two batts now but when I had a single Batt and a 65 amp alt it was ok. It only runs the fans when you are in traffic and then only runs till it cools the engine down. Draws about 30 amps for about five minutes. When driving on the highway or through town the fans don't come on. My sensor goes straight into the upper radiator hose.

[sev85]

hey fellas sorry its been awhile since i have posted on this thread i had yet another car wreck after purchasing my wife a new car she got side swiped by a county vehicle and yet i have another car totaled and more insurance and lawyer battles going on so it put my old 82 gmc on the back burner for awhile.

I did some test running on my truck with the electric fans hooked up and i have noticed on low speed with the voltage regulator hooked up under normal operating conditions they cool fine but when im wheeling and mudding its just not enough to keep it cool when your really getting into it and i never did find a sae threaded fan switch so i broke down and bought the hayden 3652 electric fan controller and am wiring it to run the fans at full speed in the adjustable temperature range im looking for i also found out these are roughly 3000 cfm a piece electric fans and have a low voltage draw so got lucky there on them being single wire fans

now my question the instructions for this fan controller say to surface mount the probe on the fins of the radiator and im just wondering where would be a good place to mount the probe as obviously the probe is gonna get different readings depending on where it is mounted any pics or suggestions? It came with a disc zip tie with a p clamp that passes thru the fins and the p clamp holds the probe to the fins for mounting im thinking right next to the top radiator return hose from the block to the radiator would be the best place to mount it

also i have decided to use the controller as the trigger for the trigger wire on the 75 amp relay instead of using the controller itself to power the fans like the instructions say to hopefully prolong the life of the controller

here is a pic of the controller i bought and i will get updated pics of my wiring harness and relay box and how everything is mounted hopefully today and try to get you guys updated