Retrofit Spal 30100320 cooling fans

I had been wanting to do this upgrade for a while. A few years ago, one of my OEM Lucas fans died and FSoB replace it with a Spal A48-12S. Knowing that the other OEM fan would eventually crap out, I decided to just replace them both with the 30100320. I know that there is a kit available on eBay for this retrofit, but it seemed like a pretty simple fabrication so I did it myself using some 3/16" steel plate, sections of 3" OD exhaust pipe, allthread and a handful of nuts. It was not clear to me how the parts in that kit are held together, but I used allthread at the sides of the can and nuts welded to the new backplate to hold it all together and the center bolt is just there as a fake motor shaft. I'm hoping to get out this weekend to see how well the new fans work.

Hopefully this will spark some useful ideas for someone out there

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This is my understanding as well, but I didn't measure anything yet. My multi-meter can only handle 10A and I didn't want to damage it. I still have the Lucas fan and the Spal A48-12S so I may measure both at some point when I have a safe way to do so. While I had all the fans out, I did plug each of them into a 12V power supply just to get a "feel" of how much air they moved. I was surprised that the both the Lucas and the Spal A48-12S "felt" like they moved more air than the Spal 30100320.This was of course the unscientific "air moving across my face" test. I'm sure the results are much different when we're talking about pushing air through the radiator core.

For those who have done this upgrade, did you notice a difference in coolant temperature according to the gauge?

 

Yes, good tip. I always forget about using this trick. I have a ton of random resistors so I'll try it out the next chance I get

 

Good to see that the seller has a complete kit with fans now. The last I looked, the kit only included the mounting brackets. For anyone looking to do a fan upgrade, this updated kit is a good one-stop-shop option. I read through the original Fchat post with all the photos and the one shot I didn't see in the post or the old listing is the backside of the plate that mates to the Spal fan. It's in the new listing and now I see how the can attaches to the plate and the cutouts in the plate to accommodate the motor and wiring. One thing to note is that their mounting plate has one mounting ear cut off, presumably for clearance in the GT4. In my 308 GTS, I was able to use a full 4 sided mounting plate as there were no obstructions to clear.

 

I finally had a chance to go for a drive and I'm really happy with the results. With the old fans, once warmed up my temperature gauge was always above the midpoint of 195F. In roughly the same outside temp of 80F, the needle never got above 195F even sitting in traffic with the A/C on. Definitely two thumbs up on the new fans.

Before signing off this topic, I wanted to do some myth-busting on the old fans. Since I had three, I decided to measure the running power draw and I was a little surprised by the results.

OEM Lucas 7.7A
Spal A48-12S 5.3A
Spal 30100320 6.1A

I was expecting the differential to be much higher between the Lucas and the Spal 30100320. 1.6A is not nothing, but not the big number that we've always speculated. I was really surprised at the direct OEM replacement Spal A48-12S at just 5.3A.

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Just for fun, I decided to punish the Lucas a little to see if I could get it to draw more amps. With it running, I heated the motor body with a heat gun. I tried to get some temperature measurements with a cheap infrared meter but was getting wildly different results, probably due to the shiny surface. I heated the motor for probably 5 minutes and I suspect it was about 150F. The draw increased from 7.7A to about 8.3A so the added heat didn't seem to make much of a difference in power draw. I did notice that the Lucas made a lot more noise the longer it ran. It was squeaking, creaking and groaning like it was about to give up the ghost.