Kncsdad

Hi everyone, I want to put dual electric fans for a new radiator on my 330ci. I already have new gauges so I used the temp sensor port on the intake for those. What is the best way to wire the new fans? Do I need to have them on a sensor or just on whenever the engine is running? My car is basically a fair weather cruiser so I really want to keep it from overheating. Everyone on here is awesome, so thanks for any advice you can share.

Fun71

My advice would be to NOT use electric fans.

There have been many, many threads over the years from people who installed electric fans and are trying to figure out why their engine runs hotter than it should. The factory mechanical fan moves a lot of air and has around 50 years of demonstrated capability of keeping the engine cool.

Kncsdad

I have also seen posts about leaving the mechanical fan on as well. The fan shroud is missing so maybe replacing the shroud and a new radiator will do the job?

sysmg

Electric fans draw a lot of amps. You would definitely need a relay. You also might need a bigger alternator and beefier wiring between the alternator and the battery. Stick with the mechanical fan, with clutch and fan shroud.

Sugar Bear

The factory cooling systems worked well when in proper order. X3 to no electric fans. Are you experiencing cooling problems?

Good luck!!!

Kncsdad

Yes and no. I haven't driven it a lot but it seems to just run hotter than it should. I want to put in a new radiator and it came with electric fans. It doesn't have a fan shroud but the only thing I can find is for a '65, nothing for a '66. I guess I should do the radiator and see how it does after that? Thanks for the input and suggestions 🙂

fleming442

I'm a fan, but as mentioned, you need to feed them. That means bigger alternator, bigger wire, and relays. I use a Painless thermostatic switch in the manifold to trip the relays. I had one fail, once, so I made sure to run a bypass/full on switch within reach.
What do you mean by "seems hotter than it should be"? 200⁰ is not hot; 240⁰ is.

Fun71

It sounds as if you already have the radiator and fans. I guess you should tell us more about this setup so we can comment on if we think it will work adequately or not.

Kncsdad

I will admit, I got a little excited last year and had big plans and bought parts but ran out of time before the weather got cruddy. When we were tuning the carburetor and doing a few things, we would take it out for some test drives(only a few blocks), we could hear the coolant bubbling so I figured before I really started driving it, I would tackle the cooling system. A few of my friends who all have classic cars kind of steered me in the direction I went. We have Hot August Nights here in Reno so I just want something I can cruise in and maybe drive on the weekends. This was my dad's car and when he got sick, he didn't want to work on it but didn't really want anyone else working on it either. I promised him I would keep it and get it running good again and hopefully pass it down to my kids to drive. I had the front brakes converted to disc's and the whole suspension system rebuilt along with new 17" wheels and tires. I am certainly open to everyone's expertise and I know there are a lot of ways to do things so that's kind of where I'm at. Just working through a checklist of things right now.

Vista67

Great story - keep that family Olds on the road.

You are getting good advice here to go with the original shroud/fan/clutch setup. Before I knew what I was doing I went down the same path you are on with the electric fans, and it took me a while and more money than I anticipated to get things sorted out. You need a good set of high powered fans that have a shroud that will cover nearly the entire radiator surface and seal up well at the edges. For any fan that moves enough air to keep things under control as you crawl along in a traffic jam on those hot Reno summer days you will need each motor on a relay. You will also want an adjustable thermostat (or better yet two) controlling the relays so you can dial in the temperatures you want. That relay and temp control setup (many choices - check Summit) will cost you somewhere between $50 and $200 (and you get what you pay for). You are also in for a lot of DIY wiring time and a bunch of wires running around the engine compartment that are hard to hide away. When you get it all dialed in and running right you should be able to match the cooling capability of the stock cooling setup with the shroud, thermal clutch, and steel fan.

You can still find the 66/67 stock shroud reproduced and sold by Year One and no doubt others for around $250. They also reproduce the steel fans for around $70 and you can buy new thermostatic clutches at any of the regular parts stores (check RockAuto). The shroud is critical to getting the stock setup to work properly, with the outside edge of the fan blades about 1/2 way inside the shroud. You should also check GM Sport Salvage in Stockton CA, as they are likely to have everything there for you in good condition, original GM parts for less than the reproduction stuff.

fleming442

If the coolant is bubbling, I'd be checking for a blown head gasket.

Olds64

If you go to electric fans or already have one be aware that you need either a high dollar electric fan or an OE fan from the salvage yard to match the cooling capacity of the stock fan and mechanical clutch. I have an electric fan on my 71 98 out of a mid 90s Ford Taurus with a 3.8l. My 86 Ford truck has a dual electric fan from an early 2000s Ford Windstar. They cool just fine. I actually have a cheapie Summit electric fan in a parts bin in my shop. I don't remember how I got it.

BangScreech4-4-2

Best advice is to revert to factory-type system and make sure you install a shroud.

oldcutlass

The factory system without air was a 4 blade fan and no shroud.

BangScreech4-4-2

If it worked then, it'll work now. I would still go with the addition of a shroud, though.

sysmg

True, but it's easy to upgrade to the AC fan, with clutch and shroud.

matt69olds

Before spending a dime, find out if it really hot, or just bubbling. These cars didn’t come with an overflow tank, you can’t fill the radiator all the way to the top. You have to leave a little space for coolant expansion. If you fill it completely, it WILL burble and puke coolant.

Get some real gauges so you know how hot the engine really is. With a little creative plumbing, you can keep the factory idiot lights as an attention getter, and the gauges for real useful information.

If it really does get warm, pay attention to WHEN it gets hot, not just the actual temperature.

Make sure all the factory ducting, baffles, tar paper, and seals are in place. There is probably rubber seals that close the gap between the radiator support and the radiator itself. Make sure any air entering the core support goes thru the radiator and not around it.

The is a “chin spoiler” or baffle that hangs down below and just behind the radiator. It’s purpose is to creat a natural low pressur area behind the radiator to encourage airflow thru the radiator.

A fan shroud never hurts. Put a good 7 blade fan and thermal clutch on instead of the factory fixed 4 blade. The thermal clutch only engaged when the engine gets hot enough to need the fan, any other time it basically freewheels and is just along for the ride.

These cars didn’t overheat when new, assuming they are properly maintained and in good condition they shouldn’t overheat now. If they do, it’s more than likely due to something someone threw away over the years.

Electric fans aren’t the fix. A good mechanical fan will pull more air than electric. If electric fans were better, big trucks would use them. The biggest advantage to electric is the will fit places mechanical fans won’t (transverse mounted engines) and the ability to turn them on and off (big advantage with the OEM, the engine warms faster and helps meet emissions requirements)

Kncsdad

Thank you guys so much for all the great information. I think at this point, I just got the gauges installed so I feel like I need to run the engine to see what the actual temperature gets to and go from there. I am planning on doing a radiator flush and I still want to replace the radiator because it had some repairs done to it that weren't great. I think at that point, I will see how it's doing and then just add the fan shroud for good measure. The car had an aftermarket AC unit in it at one time (good old Sears and Roebuck) which was removed but it does have the 7 blade fan. What a great knowledge base you all have and I am very appreciative. I will keep you updated on how it's going and try to post a couple of pictures. Thanks again and happy motoring 😁

cfair

Another vote against electric fans. They’ll work, but you’ll be stressing an electrical wiring system which was never designed to support that kind of amperage load. If you go that route (I did in LA in the 80’s), run it through a relay and do not zip tie the fans through the radiator. Fan vibration will eventually cause a leak.

40 years with these cars, here are my suggestions:
1) known good (i.e. recored or new radiator core) 4 core radiator, high fin density. Get the one that fits your car with maximum fin density. If in doubt, get one that’s spec’d for A/c cars.
2) 7 Blade GM factory fan. Just make sure it’s setup to spin the right direction on your Olds. Match the fan outer diameter to your existing fan. Simply put, more blades = more cooling air through the radiator. Sometimes this comes at the cost of more noise. There are many 7 blade fans, get a few from the boneyard to find the best noise/CFM trade off.
3) Hayden fan clutch. They freewheel when not needed due to low temps & kick in due to elevated temps. Just what you want: mechanical = no electrical modifications, and it is as Olds intended. Up to you what model. See my posts on what model, temperature kick in & lengths.
4) Flowkooler water pump. Within the factory housing, they made a better impeller. It helps. Or maybe there are better. I’m happy with the brand.
5) Shroud that covers the whole rear of the radiator. In my ‘66 big cars, I had to cobble up a solution from multiple shrouds. May you be more fortunate. Mainly, just get/build a shroud that covers the whole rear of the radiator so the fan really pulls air through the radiator.
6) Make sure your car has the rubber curtains all around the radiator: top, bottom, left, right. As installed from the factory, the rubber curtains more or less force any incoming air through the radiator core to cool the engine. Think of them as a “front shroud”. In short you want incoming air forced through the radiator core, not slipping around its edges where it does your engine no good.
7) Coolant mixture. There are a lot of opinions on this, but I’ve had good results in NorCal with the following recipe: a) 1-2 bottles of “water wetter/photo flow” chemical solution; b) 70% distilled water; 30% yellow anti-freeze.

What little I’ve learned running these cars in CA for 40 years or so. Hope this helps.

Chris

Kncsdad

Hi and a huge thank you to everyone that responded to my thread. I did end up going with the electric fans since I already had them. I did use your advice and replaced the radiator, dual fans with a full radiator shroud, new water pump, thermostat and hoses. I did run relays and a inline upper radiator hose thermostat housing(my only choice for now) plus all new wiring to go with them. The car stayed around 180-190 most of the time. The only time it got close to 220 was standing still in the cruise line. Overall, it went well for the first time out.
Now for my next project. I want to swap out the old points distributor for a HEI distributor and coil and I wanted to know what my options are and what you guys have had luck with? I know MSD makes a good product but it is pricey. I also saw one by Petronix called the Flamethrower? This time I haven't purchased anything LOL so I will see what you think?
Thanks again for the input and expertise.

cfair

I’m glad the electric fans are in & working. The key thing is to not warp a head from overheating. From what I’m reading you’ve got a couple of redundant systems which should protect you from overheating in traffic you can’t predict. That’s where you want to be.

Modern cars, in part owing to emissions, run a lot closer to 220°F as normal, but that’s too hot for our old iron V8’s which were designed to run around 180-200°F. Check the temp gauge and you’ll learn where the car gets near the safety margins. If you’re below 220, don’t freak out like I did for 30 or more years trying to keep temps at 160 or 180. At 160°F you may get worse fuel economy from forcing temps too low.

Distributors
I’m just 1 guy reporting in, but my ‘66’s started with points as you would expect. Somewhere along the line in 80’s I heard about HEI & was glad to leave points in the rear view mirror. No dwell to adjust, or points to file and all that other stuff. But, HEI electronic modules die without warning. So carry a spare in your glove box or trunk, plus the tools you’ll need to do the job. Just to put it out there I tried Mallory Hall effect, maybe MSD and on & on. My last HEI distributors were from Taylor and were o.k., but I had a helluva time getting the cars to not knock at part or full throttle on today’s gas.

Sure, I could have turned the timing back, but then the cars didn’t idle well. So I had 2 bad choices - good idle & knock in the upper RPMs, or bad idle & no knock.

This p*ssed me off enough that I got into using Cadillac and Buick HEI vacuum cans just to keep the advance from going into knock territory. Plus fiddling with crappy advance limiting solutions.

About a year or so ago I came across Progression Ignition distributors which allow you to control timing at each RPM level with a Bluetooth map from your phone that’s installed into a memory chip in the distributor. I was at my mechanic’s shop and a Pantera guy was explaining it. The short version is you configure and download a map to the Progression HEI from your phone. So, if it pings at any RPM, you reprogram the map. No springs, weights, goofy advance limiters - just write a new map in your phone and send it to the distributor.

The unknowns with Progression HEI’s is how long they’ll support the software to program the HEI and how long their custom circuit board will last in use. All I can say if you have these concerns is “so far, so good”. In my head I’m in what we used to call “TNTR” in my business: Too new to rate.

What little I know. Hope this helps
Chris

gs72

Look at Progression Ignition distributors. They are fully electronic and you adjust the timing curve from from a phone app through bluetooth.

Andy

I went back to factory 4 blade, no shroud..South Florida just to hot in summer for that to work..new 3 core radiator, ended up using a 7 blade fan with a standard clutch fan..still likes to go to 225 at stop lights…may need to do a heavy duty clutch..finding a good shroud is very difficult..I may try to fabricate side slats to help pull more air thru radiator

Kncsdad

Thank you cfair and gs72 for the good information. I honestly haven't heard of that distributor so definitely something to look into. My only question is on the programming? Do you have a starting program and go from there or do you have to program it from scratch?
Thanks,
Gary

matt69olds

HEI and a MSD 6AL ignition box. About as simple and reliable as you can get. It’s very easy to fabricate a harness using a HEI module to bypass the ignition on the VERY remote change the msd fails. Put it in the trunk and forget about until you need it.

If you don’t want or need an ignition box, HEI with a good ignition module is even easier. The biggest issue with HEI is the module. Most modules are flat out junk. Find an older A/C Delco module, I’d prefer good used A/C Delco to the parts store crap sold today.

Or, you might just consider keeping the ignition points. Yes, they do require a little maintenance, but that’s an opportunity to forget about life for a little while.

if you can’t spare a couple hours a year in the garage for a little “special” time with your car, what’s the point of having it?

Kncsdad

Thanks Matt69olds, you have some really good information. I certainly have some things to think about and you are spot on when you say it's a good opportunity to put life on hold for a bit when you are wrenching 😁

Fun71

I installed a used 1978 GM HEI distributor in my engine back in around 1986 and it’s still running fine. I made an advance stop for the 24 degree vacuum canister so it’s set to 10 degrees now.

gs72

Here is what the table screen looks like. This is a base map that comes up when you start to generate a table. You make changes to it to suit your engines needs.