talk to me about the MP P4120758 viscous fan clutch

[Nacho-RT74]

Good ? bad ? works for AC cars just on the way it is or better the stock 7 blades fan ?

[flyinlow]

Never did a comparison test . However you see 100 * + temps , more blades if the diameter and pitch remain the same  equals more air. ( more noise and engine drag  and  load on the fan clutch also)

[elacruze]

Good ? bad ? works for AC cars just on the way it is or better the stock 7 blades fan ?

The 5-blade package fan will probably be quieter, and move as much air.
You could be the one to run the experiment and tell us..!

I would probably keep my 7-blade just because it's correct.

[Nacho-RT74]

yeah I would keep 7 blades too because is correct, but is the MP clutch a good product ?... I have got two times Hayden clutch and honestly, never got satisfied with results

[elacruze]

What exactly is the issue you're trying to solve?
Hayden makes good units, as far as I know. I probably installed 20 Haydens in '90s GM P-Chassis vehicles, and they were all good...

One thing I would like to see, which never seems to be published, is the air temperature at which a fan clutch engages. Just to have some information to test with.

[flyinlow]

Seamed to be just below the engine thermostat temp. For example , if you had a 440 engine with a 195* thermostat and you started a cold engine and left the carb on the fast idle step running ,say 1800 -2000 rpm. You would hear the fan initialy rev up , then since the air thru the radiator was still cool, the fan clutch would start to free wheel. Still turning but not as fast as the waterpump was turning. After the radiator warmed and the fan clutch sensed the temp increase in air thru the radiator the clutch would shift to its high airflow mode. Still not locked-up ,but with the fan running almost the same speed as the waterpump. You would have to keep the radiator cooler then the engine thermostat temp rating for proper cooling so I would say the fan clutch in this case would "engage" as about 170*.

Never have seen specs however.

[Nacho-RT74]

dunno really wnat can I say but the clutch I have spins a lot winding it ( winding ? is that the right therm ? )... maybe 1 complete turn or even little bit more when HOT. Several clutchs I have compaired barelly gets half or MAYBE 3/4 turn as much. in some cases COLD.

BTW the first Hayden replacement clutch I got just got 3 or 4 years last long... the ORIGINAL FACTORY ON MY CAR got allmost 30 years!!!! as far my knowledgement never replaced by original owner.

[flyinlow]

If the fan is balanced well and the waterpump shaft runs true , the original clutches last a long time.

I have drilled a small hole in them ,added silcone oil and soldered the hole shut and gotten several more years out of them.

[Nacho-RT74]

same fan allong the years. Only difference is it was painted in the past and I removed paint from blades and polished a litle bit

water pump... well, has been replaced once with a replacement unit from box... got damaged and rebuilt the original "pentastarted" factory one ( new seal and bearing )

[Nacho-RT74]

well I don't think something can go wrong on $45 ( plus Shipping ) for the MP kit, I guess ( and I hope ). Locally, Hayden stuff is priced at least double of that.

[Nacho-RT74]

BTW actually does somebody has this fan clutch on his car ? would like to see a frontal view of it.

[Purple68]

I have it on mine, not the best picture but all I've got.

[Purple68]

Found one I took before it was installed.

[Nacho-RT74]

OK... I thought it was a heavy duty one ( without the brass plate ), like this one:



Suposelly these are Heavy Duty, and the other ones are standart.

Oh well. I hope will be better than the one I actually have and I didn't spend the money without need to spend it.

Thanks for the pic!

[elacruze]

 

[Nacho-RT74]

 

[Purple68]

Hey Nacho, I just realized the first pic I posted had the Hayden 2765 clutch that is for the Jags.  I thought I was going to have clearance problems with the rad. In the second pic is the clutch that came from Mopar Performance.

[elacruze]

This is good stuff, my fan clutch is original and works, but since I'm planning on doing so many miles I'll install a new one anyway for insurance. I have wondered myself what to buy.

[Nacho-RT74]

Hey Nacho, I just realized the first pic I posted had the Hayden 2765 clutch that

I think is the same one I have running right now on my car...

Why clearance problems with the MP unit ? seller of the unit I got is acclaimning same reason to sell, clearance problems on his 69 RR... quoting:

I bought this to be used on my '69 Plymouth Roadrunner but it didnt have enough clearance for what I needed.

[Purple68]

I've heard of quite a few guys having the fan too close to the rads with the MP unit. I had the wrong rad before and that may have been why I needed the Jaguar clutch. Now I'm switching to an aluminum rad and I'm not sure which one I will use as the motor is out of the car again. 

[Nacho-RT74]

Ok... the pic of the Heavy Duty fan clutch I inserted becomes on JAGS LOVERS pic LOL ( logical, it was taken from a Jags website on the image search )

this is how a heavy duty clutch should look and is how did look the FACTORY one on my car and the first replacement


Maybe thats why you were laughing elacruze ? on my PC allways showed the right pic, maybe not on yours

[Nacho-RT74]

I think I have PLENTY of room on my car... the fan barelly gets in ( if really does ) into the shroud

[SFRT]

I am a bigfan of the clutch fan myself. it is the best. im running a nos unit from the late 60's and it fits just fine even with my serpentine setup. I have let my 440 4 bbl  11:1 compression car idle in traffic gridlock for over 2 hours on the hottest days with no overheating issues at all. clutchfan and 26" radiator. runs perfect all the time.bestest pic i got

[Nacho-RT74]

http://cgi.ebay.com/ebaymotors/Mopar-Performance-Viscous-Fan_W0QQitemZ170466292559QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item27b095334f



well the one I won began in $2 ( but still with box )

[elacruze]

Ok... the pic of the Heavy Duty fan clutch I inserted becomes on JAGS LOVERS pic LOL ( logical, it was taken from a Jags website on the image search )

this is how a heavy duty clutch should look and is how did look the FACTORY one on my car and the first replacement


Maybe thats why you were laughing elacruze ? on my PC allways showed the right pic, maybe not on yours

Ya shows this one-

Sorry you didn't get to enjoy the joke.