Bad Bird

Hi everyone,

The background is this. My '69 is currently fitted with dual Spal thermo fans and a good factory-fit radiator. The car runs at a good temperature and never overheats. This is no mean feat, as I live in a pretty hot climate area with temperatures that an exceed 100 degrees on a regular basis.

I personally would prefer a more stock-looking arrangement, and am contemplating going back to a clutch fan and shroud. Am I shooting myself in the foot by considering this, in light of the fact that the Spals flat out work?

If I were to go back to a clutch fan, should I find a 7-blade from an AC car? (My car is a fairly low option car - L36, M21, PS, non-AC, non-PW). I have a 5-blade and a 7-blade in the shed, but the 7-blade is from a later car (as it doesn't have the strange blade shape that the '69 7-blades had).

Thanks for reading,
-Matt

Bad Bird

Also I should add, if I were to go this path are good fan clutches still available?

resdoggie

Hayden makes all sorts of clutch fans. Got mine at Summit. I use the original 7-bladed fan and 4 core stock rad in my '76. Cools fine but I live in a more moderate climate.

bashcraft

There's nothing wrong with the stock clutch fan if everything is correct (shroud, seals, etc.). They work every bit as well as any electric fan.

I have a stock clutch fan with a '69 small block radiator cooling a zz502. Never had any problems with this setup.

Mike Ward

Stock fan with correct clutch will pull just as much or more air than a electric fan set up.

mrvette

Don't change what don't need changing, all you get is $$$ spent and for little/no gain.....in fact you can easy wind up behind the 8 ball on that....

Bad Bird

Thanks for the range of responses, guys. I will sit on the idea for a while longer before I make any rash decisions.

If I were to decide to go with the mechanical fan, does Hayden make the best clutches? Or are the Eaton ones better? Would a 5-blade or a 7-blade be better on my non-AC car?

Thanks guys!
-Matt

DUB

Sorry...here we go again. At least in this SPECIFIC SCENARIO.

Factory fan clutch that was GOOD...all seals and shrouding seal etc...factory prefect. THEN.... When I was standing there looking at the gauges when an A/C system was being charged....and the gauges read 'x' for the high pressure side....then took the car back to the shop and the A/C was nominal at best. The customer wanted better air conditioning....and then installed a twin SPAL set-up....wired them up so I could either have only ONE fan on when the A/C is on...or BOTH fans on. And when the A/C system was being checked....and the ambient air temperature at the time of charging was the SAME...and the gauges showed the lowest high side pressure due to MORE air coming across the condenser than the factory fan clutch(which was GOOD as previously stated) WHEN BOTH fans were on when the A/C was on. The A/C system will now darn near freeze you out of the car on really hot day.

So sitting at idle getting the A/C charged and checked out...the electric fans PULL MORE air than the factory set-up....and when driving down the road...well...the A/C is cold as heck....when the factory fan clutch was not all that. I guess the next time I need to get my air flow meter out and post results.

DUB

Mike Ward

No, here YOU go again.

Have at it.......................

Bad Bird

My experience has been that both can work very well. I've had cars with electric fans before and cars with clutch fans. The purpose here is purely aesthetic.

dmruschell

After building up the engine in my 79 and putting in a DeWitt's radiator, the car would still overheat at idle, especially with the AC on. The twin SPAL fans fixed that. The car hasn't overheated since they've been installed and it's my DD in all kinds of heat (except when one of the fuse holders for the fans melted with the AC on... it got pretty hot then ).

maxmachz

All the latest and greatest vehicles use electric because they are no better than the old clutch and fan? Ya right. 40 years later and there is nothing better than a fan with a clutch? Really?

Leave the electrics, enjoy better air flow and cooling when the vehicle is at a stop light or slow going through town; and when the vehicle speed provides the needed airflow the electrics shut off.

Oh, and your car doesn't sound like a truck with the helicopter under the hood when you step on it, just the nice sweet sound of true duals.

Mike Ward

Aren't you glad you asked the question now?

I'd use the fan that GM determined to be most appropriate for your car as per the AIM. For the clutch, just make sure it has the correct temp rating.

Bad Bird

I'm sorry for what I've done!

The AIM suggests using my 5-blade fan, so all I need to do is get myself a good shroud and a good clutch. The previous owner - a member of this forum - switched to the electric fans for ease of maintenance, but he said that it never overheated with the clutch fan.

Mike Ward

Yes, fans are one of those hot button questions that get people quite excited. What's forgotten is that GM built over a quarter million C3s, all of them with a clutch fan. None of them overheated when new..........

maxmachz

Bad Bird, if you are after the original look then the original set up is fine. Mine also never overheated with the original set up even with the A/C on.

The OP's request is valid, and yes, the original set up works just fine.

Just see so many better things with the upgrade you already have, I wanted to share BOTH sides of the fan saga.

bashcraft

Opinions...

DUB

I already did. Hard to dispute facts isn't it....in the scenario I described. So your statement is incorrect....fan clutches at idle... do not pull more air as a twin electric fan set-up.

DUB

SB64

Hi Matt, I tend to agree with using what GM originally had the car stup with. I do understand that technology has changed over the years also. Anyway what I wanted to tell you was that I have the whole setup if you decide to go back to stock, infact I have duplicates since I now have a donor car. just an FYI.
Thanks
Roger

Bel

My '70 has a stock clutch fan as well as an electric fan. The electric fan is never needed, up is a good backup if the need arises.