Hydraulic fan failure..

[chrisman]

hi guys, rdm had the plastic part of the fan come apart during a long run on the highway against a viper.. i was in the car, and was surprised to see steam coming from under the hood/bonnet..
the plastic blades broke/came apart.. one when into the radiator.. i am fixing the rad which was replaced before..
has anyone had this fan problem before? i ordered a new fan from lexus, and the parts guy said that he never ordered one before--but he may have been new..
is this a common problem? the only thing i could figure is that the turbos heat over time made the plastic fan blades brittle.. and the high speed drive made them give way..
any input?
by the way, the car is running stronger than ever, and i was able to pull the spark plugs finally..would you beleive that i have not even had a chance to look at them yet..they seem fine-and rdm is running a little more boost now--viper-able you could say...

 

[chrisman]

well some more news on the fan problem.. i replaced the fan, and fixed the rad.. long story short-- the new fan also failed at a high rpm..this time i saw it happen.. that rules out my theory that the heat made the blades brittle over time.. heres my new theory--the hydraulic motor has developed a problem.. the car itself has 160,000 miles- and since rdm has owned the car, it has been driven agresively..

when i replaced the plastic fan, i didnt think about checking the hydraulic motor.. i think it may have excessive play, and at high rpms woblles enough to stress the fan blades to the point of failure..
solution-- remove hydraulic fan altogther with the fan oil pump.. the car will now be getting a couple of electric fans, and the fan oil pump will be replaced with the unit/idler from the LS400.. i guess this may free up some horse power anyway..
back to the lab!!ha,ha,..

 

[Lextreme II]

Time for a set of 15" electric fans.

 

[COFFEE]

Lex,
Does your car have any problem running the two 15's power wise ?
I have fitted a thermo set up to mine, though i haven't yet driven it.
I was reading on a couple of threads the discussion of these fans drawing to much current ?
What temp did you switch your fans on at ?

Regards

Stephen

 

[SC400TT]

Let's discuss this a little more...I agree that the electric fans look like a much better long term solution to FI'ing the V8. What fans do any of you have experience with? The things I think are important are obviously cooling capability of each fan, reliability, quality, and quietness of the fans. Which ones do any of you recommend?


Ryan

 

[Zuffen]

If in Australia the Ford Falcon twin thermo fan is pretty hard to beat.

They can't draw too much power or the poor old Ford alternator would die pretty fast.

Cheap at $300.00 mounted in a cowling that is easy to mount.

 

[SC400TT]

What about the Flex-a-Lites? Fal?

Ryan

 

[Lextreme II]

When i had my twin 16" fans, i had no problem with stock altenator. However, after i added high pressure fuel pump, an additional FMIC fan and Dual MSD unit. The stock 100 amp alternator is unable to handle the power demand at night (due to the headlights). However day time driving is ok. I am going to upgrade the alternator to 175 amps once i find some money.

The 175 amps alternator is for 299. I know lots of places are selling it for 550.

 

[COFFEE]

Zuffen,
I had two brand new daviescraige items sitting at home from an older car that i use to have, i ended up selling it and new got aronud to putting the Fans on so i wish to make use of them.
I looked up the site to see what they recommened, they claimed 2x 12" fans for the 92+ SC400.
I haven't had i made yet but i am going to get a custom radiator eventually made, more cores and a little smaller.
I want to push the radiator as far forward as i can, as well all know, there is heaps of room !
This will allow for easy access to work on the engine, it looks heaps better and allows plenty of room for a blower.
I saw a thread and they were discussing the benifits of electric fans over the hydraulic set up, saying there wouldn't be any and the fans draw mass amounts of amps.
I just looked up these fans on there site and they max 7amps and the 12 9amps, I would hardly call this much.
I did how ever look around for options of thermo switches and Jaycar has a pretty impressive kit thats $70.
It has a digital display and adjustable up to 1200 celcius.
I am yet to test it, if all works well you can use it for anything from water temp to brakes, turbo, transmission, etc.

I am expecting the twin 10" not to be strong enough for the standard radiator, i think it will be fine with a 4-5 row unit.

I am just not very sure what would be the opt temp to have the thermo switch set at, i plan at having set to about 80 degres ?

Regards

Stephen

 

[COFFEE]

Lex,
My car is a 94 Limited Soarer, *** spec with all the electrical trim.
There aint no 100amp alternator in my baby about 160amp, going on the fuse in the fuse box.

I expect it should be fine.

Regards

Stephen

 

[chrisman]

after instaling 2 elctric fans on rdms car-- i was thinking that during WOT, wide open throttle, you should have the fans turn off.. its relatively easy to wire the fans that way, and during a high load/WOT , the ignition+fuel pump need all the amps they can get..
it would require a micro switch that is throttle activated, but i already have one on rdms car..
what do you guys think.?..
i should have taken a pic of the twin fan setup i just made for rdms car--kinda cool--pun intended..ha, he...

 

[Zuffen]

Coffee,

I use a Jaycar Temp switch on my car. I would highly recommend it. One of the fun bits is you sat down and built the sucker yourself.

Mechanical thermo switches cost around $70.00 mine cost about $30.00 and an hour of fun building it.

I don't think the 10" fans will cut the mustard in your Ford. Go to the wreckers and get some AL-Au ones.

Chrisman,

Rather than a micro switch why not look at a Hobbs switch that will trip when the vacuum drops to (almost) nil on the WOT.

 

[Lextreme II]

Pressure switch would be great. They run about 27 USD. However, having the fans on during WOT is not a true solution. What about daily driving? What about a hot congested traffic day? I experienced over heating last week with traffic and during a mildly hot day (90F). Right now, i have one 16" fan that is on all the time. The two other fans are on at 185 degrees F. However, dont ask me to drive this car at night until i get a larger amp alternator. The headlights just kill the whole system. Which model came with 160 amps?

 

[chrisman]

zuffen, that is a great idea.. i need to get me some hobbs/pressure switches..
david, i wish it was 90 degrees over here in chicago.. its still around freezing ,(32)over here..no over heating problems--but your scaring me.. rdm has a smaller alt that puts out 100 amp, and im starting to think this may not be enough with the 2 new elctric fans.. i know they draw about 10 amps each..
well we will see.. at least i know he wont be having the air conditioning on--its sitting at my shop in a box somewhere..ha, ha....
david, was the air- cond on when you over heated?

 

[SCV8]

Yikes, now I'm going to check for wobble in my fan motor, I rap out the car nearly every time I drive it, just put a new radiator in awhile back also.
Was going to suggest a dual fan set from Flex-a-lite, but it sounds like you have it covered.
BTW, doesn't the A/C have a feature so that it releases the compressor during WOT, if so maybe there's something useable left from that system to attach to your fan relay?

 

[chrisman]

i dont know if lexus disengages the ac clutch during WOT.. i know ford has done that in the past.. il bet the lex is also like that..

and your prob right, i could prob use that feature -thru the ac somehow.. but il bet only whe the ac is on.. i dont know if the ac electrical circuit whould even work cosidering i had previously removed all the ac mechanicals..
rdm has about 160,000 miles.. he has owned the car for prob 2 years, and does drive it hard, even befor turbos-- if the hydraulic fan motor can go bad from abuse, im sure he proved it.. ha,ha,...

 

[Zuffen]

If you use a Hobbs switch to turn off the fans there's no reason it can't turn off the air at the same time.

5-6hp gain for a little wiring is cheap.

 

[chrisman]

zuffen- lextreme had previously recomended a local parts store-in the states- that has a couple of different versions.. i will go first thing on monday to check them out..