i was told that a thermo fan could make up to 30hp more on my L18? if this is true, where could i get one?
cheers scott

And if you fit 3 thermos...

nah sorry, it is a load of rubbish. Don't listen to whoever told you that!

you might get a couple of ponies out of it, certainly not 30 big ones unless your fan used to be an aeroplane propeller . It obviously takes some power to run a mechanical fan tho.

And if you fart before you get in the car you weigh less and it'll be quicker.

Dave

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USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD

perhaps they were getting mixed up with an intercooler on an FI engine ??

I would have thought you might weigh more .......

I experimented with the standard clutch fan anf a 16 inch thermo on my wifes RB30 turbo R31.

The power loss with a clutch fan is only really felt down low......a GOOD clutch mechanisim will actually only turn the fan blades at engine speed up tp about 2500 rpm when engaged.

Look at the blades on a clutch fan, nice and wide......a thermo has typicaly got thin blades that dont move a lot of air. And on a car with a thermo fan, have the car running, then manualy switch the fan on and watch the revs drop, the fan may not be driven by the engine but the alternator has to work harder to keep the power supply up.

And lastly, the thermo just cant cool as well as a clutch fan can.

That is from personal experience.....

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R31 Skyline 4 Door.
RB26 dett power.
"Pride of 31....Power of 26"

120Y Sedan
Stock a12....NO MORE! Webber fed A15 NOW!
All of 83,000 original KMS.

I think it lowers the center of gravity, good handling improvement

thanks, i might try not eating, so i weigh less..... ok thanks i think i will be better off saving for something more worth while, like an sr20 conversion
cheers scott

An extra 30hp for an L18 would be doubling the power, man I would definatly get the themo fan. Put a Turbo Zet on there also. (they give a 200% increase in hp I think)

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Bluey S3, FJ20DET

In response to Devious-Jet's comments about the blade design on a clutch fan vs a thermo fan, you are correct but that doesn't mean the thermo fan doesn't push as much air. The only time a fan is needed is when the vehicles stationary or alot of slow driving/ bu!!sh!t hot day like one we had a few weeks ago. Otherwise the airflow over the radiator as your driving along should be enough to keep the engine within operating temperature.

Most L4's that I've seen don't even have a clutch its just direct drive which is drawing power from the engine all the time and not providing the airflow when you need it. My engine used to always overheat in heavy traffic or sitting around at idle for ages...for one reason or another. I upgraded to thermo fans and havn't looked back. I got one of those variable temp probes that goes in your top rad hose (poxy idea but as someones mentioned before a good idea is to stick a blank tube into the top rad tank and then stick the probe inside that and stick it in with a dob of silicone) and that switches the fans on only when their needed IE in traffic, sure the rpm drop down but their only on for 2 or 3 minutes then they switch off again.

Small gain in hp maybe 2 or 5hp depending on motor.

Anyway thats my 2 cents.

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78' 200B. 5 speed, extractors, 2 1/2" exhaust, 32/36 weber, 14" mags, Elec ign, Redlands motor. Slowly Pulling parts off while still driving around. Tree unfortunately signed its death cert.

Recommended Traders: Datsport

If the engine driven (viscous coupling) fan is working properly, it can pull ~ 2-3 times as much air as the biggest aftermarket thermo fans. I have no space to mount an engine driven fan, and my 14" + 12" thermo setup is absolute crap... Modern engines can get away with thermo's due to better cooling system design, higher running temps and aluminium rads (worth around 25% alone over copper due to the fins being brazed instead of soldered). But notice that Nissan, Toyota etc. still run engine driven fans for the high performance engines...

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Michael
'71 240Z, RB20DET.
'89 Nomad (needs speed).

Its all true, double your horsepower, just asks one of the genius's on nissansilvia.com/forum



I loved the engine fan on my old L20B, that sound, along with the twin 45's made a really nice throaty note when I was giving it a hard time.

Why bother with a thermo for such a simple motor setup anyway, its just means something else could go wrong.

my Monaro came with a light weight fan & it was hopeless in traffic.
A trip to the wreckers & a nice viscous clutch fan solved all of those problems, & i couldnt tell any different in the way it drove, only that it ran cooler

i think the trouble with a engine fan on our old L motors is that there is probably no radiator shroud leading to it. that with the fact that it sits an inch or so away from the radiator creates inafectiveness in the setup.

modern vehicles have this shroud.

a thermo fan will sit on and draw only air through the radiator. MUCH BETTER


as for HP Gains? it all helps no matter how negligable.