The distance from the fan to the rad is something I never thought of before...If either fan is inside a shroud, why does the distance make a difference?

 

Alright, in random order:

Cobalts are available (or will be available) with 300+ hp, as are SRT-4's, both in a turbo application. Grand-Mont-Impal-lure's are available with 303HP V-8's, transverse FWD & Auto tranny, A/C, and a much higher GVW than an RX. If there is an efan alive that will handle a 400hp rotax, this is it.

Looking at the Black Magic fan, I don't see it as a great design. The $20 pick-your-part cavi-fans on my rx (NA, 180HP), and my truck (NA, 150HP I4) will actually beat the thermostat at idle, and bring temps below "normal".

Aaron: it is not so much the distance from the fan to the rad, as it is the distance from the tips of the fan blades to the shroud. 1/8" [0.6% of fan radius in the test] difference in this area is in the neighbourhood of 30% flow loss.

And yes, with efficiencies being equal, it takes X power to move Y air. However, going mech to e-fan, you get + efficiency losing the mech fan, - efficiency for the mechanical-electrical-mechanical conversion and + efficiency for the airflow through the e-fan. OH, and the e-fan ALWAYS runs at its most efficient point. The mech fan is only efficient at 1 point in the range.

Last undiscussed e-fan bonus: If your air pump is missing, you don't need a dual alt pulley or a yoohoo belt if you ditch the mech fan. Actually, thus is the most straightforward way to estimate the clutch fan HP: more than 1 belt can provide, less than 2. Belt calcs are pretty easy too.

 

Great discussion regarding e-fan vs. clutch fan.

And Great Job Kevin, engine looks nice, and like others said that garage is sweeet .

 

Ah yes, I forget that the tip of the blade accounts for something like 90% of the air movement. Since the fan shroud needs to be looser then the e-fan due to engine movement, I can see how the e-fans ducting would be more efficient since it's closer to the blade.

I still question the overall efficiency though...The alternator is about 60% efficient on a good day, and automotive electric motors....well, they suck. The "system" burns up quite a few watts in heat (as I show on my e-fan myth page with math).

 

Clearance on the flex-a-lite 150 is 8 mm, just over 1/4". How does this compare to the clearances on the GM fans? I am still genuinely interested in this 2 fan idea if it actually works...

A practical problem with these Efans is the triggering temp. As you said it's a step thing, which poses the problem: what temperature do you want it turning on? What temp off?

One advantage that no one mentioned is with E-fan you can run that retardedly designed CP racing strut tower bar that requires you to cut the blades of the stock fan.

 

LOL....all I said was I didn't like the look of the clutch fan hahaha.

Some wicked info here though.

 

LOL....You mean the CP racing P.O.S. that you also have to take the cover off the fuse block and looks like a child designed/welded it up.One of just many thoughtout/tested/great products they make( in the driveway ).

 

Actually it was a BARN :p

 

Yes, that would also be the one that rusted while sitting in my basement dry since I couldn't install it...

 

Looks awesome dude.

I love seeing engine build pics. And you're going for the same popular Silver/Black theme I am

Can I borrow your 52mm socket? lol

Jon

 

It was 2 1/8" and no, it's not mine. If you can get the 54mm nut off with a 52mm you are god. :p

 

O-town has a princess auto. Buy, use, return. No questions axed.

 

I've never seen the 21/8" socket at PA, maybe I haven't looked hard enough.

 

Comes in a big and expensive kit of 1" drive sockets. I did shell out for the 3/4-to-1" adapter.

 

Here's the post that convinced me to get a Fiero fan after first trying one from a Taurus.

https://www.rx7club.com/forum/showth...threadid=29465

I put this in with a Flex-a-lite temp switch set at 195F and haven't had a problem.

 

I started taking some pix and measurements last night. Will post up soon, in a new thread.

the GM fan has some neat tricks for sure.

 

One really nice feature on the stock clutch fan is the ability to use it as a tool box when doing under hood work.

 

Amen to that!

 

Frank, hows your new motor?

 

Frank has a new motor..where is the old one?..and Yes,Princess Auto now carries the 2 1/8 inch socket..I think it's 16.49(?)..it is in One Inch so you Possibly would need an adapter.they do have a One inch "persuader bar" for 40.00 though.it's about 4 feet long!

 

I guess I could update, I've already put about 500km's on the engine, should be doing an oil change tomorrow if the weather holds out, should be broken in this week.