Scarebird

In my 1971 LeMans L84 conversion, the norm is to run an aluminum radiator with a pair of electric cooling fans. Bollocks.

I find the old school thermostatic clutch fan dead reliable and very simple, looks period correct and confuses "experts". Note to mention it is one less thing to go gunnybags!
I noted on my 2020 5.3 crate motor that the water pump had a threaded section - this intrigued me.
Measurements show it to be a M30-1.5 thread. Why? it served no purpose in installation and as far as I can see no use in rebuilding the pump. By dumb luck I noted in a youtube video that a Ford Ranger had the same thing. The water pump seemed suspiciously centered in the radiator shroud too... this is the pump: GM 12687631

no way the thread and pitch are the same...





Way. I ordered a HD blade section and clutch - it fit perfectly.



I will need to notch the fan blades a bit and shorten the air intake elbow but this is easily doable. Part applications is 1990- 2011 Ranger 4.0 w/ HD cooling:

Blade:




VDO / CONTINENTAL FA70332 {F3TZ8600B, F3TZ8600C, FO3112102} Info
w/ Heavy Duty Cooling
$19.29


DORMAN 620112 {Click Info Button for Alternate/OEM Part Numbers} Info
Automatic trans.; w/Super Duty Cooling

Clutch:



Severe Duty - Thermal SKP SK36720 {6L2Z8A616BA, 6L5Z8A616BA} Info
$33.89

GPD 2911246 Severe Duty Info
Severe Duty
$40.79

GMB 9252040 Thermal; Severe Duty Info
Counter Clockwise (Reverse) Rotation (Only 1 Remaining)
$41.79

HAYYDEN 2794 Thermal; Severe Duty Info
Reverse Rotation
$42.89

FOUR SEASONS 36720 Thermal; Severe Duty Info
Reverse Rotation
$45.79

FVP 9252040 Thermal; Severe Duty Info
Counter Clockwise (Reverse) Rotation

Fast355

'
FWIW the Express vans still come with mechanical fans. Ecotec 4.3L and 6.6L gas vans both have mechanical fans.

Scarebird

I am finding this out. I wonder if the GM fan will fit most classic fan shrouds?

Fast355

I have one on a 6.0L in a 1983 Chevy. That being said M30x1.5 is the normal GM fan clutch thread all the way back to the 350s.

Scarebird

I did not know that - getting the Big 3 to agree on anything is the Second Coming...

I clipped the tips a bit to clear the fan after I mounted the radiator and shroud. I ginned up this little widget out of tin
so all the cuts would be the same. I used a pair of bull snips and finished it off with a file and sandpaper.



The 90 degree inlet was trimmed back a 1/2" also and mounted. Clears the fan now by 3/8"

Fast355

I know this is an older post, but I have also discovered that Dodge uses the same thread size and pitch for their screw on fans. The 02-08 4.7L Rams use a clutch with a longer threaded barrel. If the LS/LT engine is mounted in stock location relative to the transmission bellhousing compared to an older SBC, the Dodge fan clutch will push the fan farther forward, better aligning it with the shroud and giving more clearence for the intake tubing. For the best operation, quiet running and highest airflow, you want 2/3 of the fan blade inside the shroud.

Che70velle

iTrader: (6)

Good to know sir.