The Fan Shroud Thread

[highwind]

is anything detrimental going to happen to the van?

http://i5.photobucket.com/albums/y160/ThePoliticalThinker/StanceWorks/20141003_151226_zpsecwc1kh8.jpg

[timsrv]

The shroud is a very important part of the cooling system on the van. Other cars may or may not need this, but the van radiator is behind the floor boards. It needs this shroud to direct the air up & through the radiator. Without it much of the air that goes through the fan will bypass the radiator. As a result you may end up with an overheat condition. Tim

[highwind]

how bout all that foam stuff..... it kinda crumbled away.

[timsrv]

how bout all that foam stuff..... it kinda crumbled away.

That's not so important. To help understand the shroud's function better, I'll elaborate a bit in the form of a question:

Q: What activates the clutch fan?

A: Hot air from the radiator generates movement of the bimetal thermostat, and that activates the fan clutch. For more info CLICK HERE (http://www.toyotavantech.com/forum/showthread.php?1725-Fan-fluid-coupling-(fan-clutch))

So, if that fan shroud is left off, the fan will suck much of it's air from under the van instead of through the radiator. This air is cool, so the clutch will never engage the fan.........even during an overheat condition. So just by removing the fan shroud, not only would you be reducing the effectiveness of the radiator, you would also be disabling the clutch fan. Tim

[djshimon]

Not sure it's in this thread but the lower shroud is usually missing on these vans and that makes a huge difference with cooling and clutch fan operation. I didn't even know it existed until somewhat recently thanks to Tim. My van gets hot on the hills-doesn't overheat but still has me staring at the temp gauge-I will eventually add a piece of sheet metal to make up for the lost lower shroud, or go the electric fan way.

[Chardog1971]

after replacing the head gasket on the 87 I put it back together and still ran hot. then I had the radiator cleaned at Parker repair Livingston Montana. put it all back together and drove about 20 miles @ 45mph no problem. then up to speed and heats up. turns out there is no fan shroud on the bottom. I should be able to fab one using the one from my 89 as a template. that is unless some one has an extra they want to sell. Thanks for all the knowledge:redvan::yellowvan::greenvan:

[LightBlueToy]

Does anyone have a picture of this lower shroud? I can't see where there would be one on mine. Seems to be one self contained piece that comes out when i remove my fan shroud.

[timsrv]

The lower section is just the part that would interfere with the fan if you were to slide it up and out. It snaps on/off the main part of the shroud. Sometimes lazy mechanics leave it off because it can be a hassle to snap it back on correctly. They may get away with it on conventional designs (radiator up front), but on the van it's much more important to have a complete shroud as the fan will suck air from the open section. A complete shroud is necessary to maximize air flow through the radiator.

Here's one for a 2wd:
http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_4167_zps3imqk47r.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_4168_zpsjlnrnzir.jpg

And here's one for a 4wd:
http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_4169_zpsujpadyoe.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_4170_zpsbp5vp1vr.jpg

[LightBlueToy]

Yep mine is missing. Anyone fabricated something to fill the void and want to show it off? Not excited about waiting weeks/months/years to track down this important piece of plastic someone carelessly threw away.

[Tan Van]

I was able to wiggle the clutch and fan as one piece in and out of the bottom of my 2wd van... which now makes me wonder if my entire shroud is still in place.

Update:

Wow---it's missing... (The bottom piece of my shroud)
It was 9 degrees this morning so I don't care right now, but, a Spring-project is in the plan...
If anyone has a cool home made shroud-bottom can you post a photo and a "how-to" ?

[LightBlueToy]

Wow---it's missing... (The bottom piece of my shroud)
It was 9 degrees this morning so I don't care right now, but, a Spring-project is in the plan...
If anyone has a cool home made shroud-bottom can you post a photo and a "how-to" ?

The affliction of a lot of vans and I feel like a lot of people don't even realize it. I didn't for the first while of having my van. And I think the lower shroud piece is crucial. I noticed a difference when I rigged up a piece of sheet metal where the original piece should be. Its not pretty or quite as effective as the original piece but I have been looking for one for a while now. Vans in the junkyard usually have no lower shroud. So yeah just used sheet metal, I don't know what else to say really, be creative and you will figure out something that improves cooling performance.

It looks like it would be a little easier to fabricate one for the 2WD than the 4WD at least

By the way if anyone has a spare lower shroud for a 4WD van (doubtful) and needs a lower for a 2WD van i DO have one to trade.

Good luck

[Carbonized]

Something like this?

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[LightBlueToy]

100x more elegant than mine. I know you work with esoteric (to me) composites and such, but how did you go about making that?

[Carbonized]

It is a long story. First I have to thank YOU (LIGHTBLUETOY) for letting go of your spare 4wd rad. and KINGER for the same with the upper main shroud. Also Tim for the picture (re-posted 10 posts above) of the lower shroud piece as it was the only thing I had to go by. I want to start proper thread for the shroud and try not to further highjack a thread about fan clutch. I did a lots of reading when I found out I had a 2wd rad. in my 4WD, I have so far 11 threads book-marked as having somewhere some posts related to over heating due to rad., fan, clutch, etc , some of that buried in threads started about water pump or hose of death or this or that. So I plan to use that thread as a " clearing house " for these cooling issues, fixes, solutions, experiments (electrics) etc.. get all the links together in one place.....

Anyway, at the shop where I had L.B.TOY radiator re-cored the owner's father remembered very well these van (the son not so much), he called them "knuckle busters" he unapologetically told me that usually they would invent a few new birds name trying to put that shroud piece back in before it found it's way to the bin, after a while {the thing would find the way to the bin "by itself" 'soon as it made it out of the engin bay}:LOL2: That's one of the reasons they are mostly extinct now!

The thing is most of us do not know that it should be there, never mind how critical that piece is to the health of the system. Missing it is bad in more than one way:
1) Due to the positioning of the radiator fresh air already has a hard time finding it's way to the fan through the radiator, if you allow the air to easily find the fan from under the van, that's exactly what it will do, by-passing the radiator in the process: bad news for cooling.
2) Fan blades are small wings. Putting the rotating blades in a shroud is like adding end plates to a race car wing or wing tips to a aircraft wing, in effect (in very, very, simplified terms) making that blade/ wing thinking it is longer than it really is therefore has more surface area. In case of a fan we are talking about a disc, at 3.14 x the extra length, it quickly adds up! Take away that extra bit and see the efficiency of the fan drop dramatically in term of CFM. Again, bad news for cooling.

So I decided to make my own 4WD Lower shroud. I had a complete RWD shroud and Tim's picture to start from. Due to a couple of hurricanes I didn't and still do not have a van for test fit so that is still a ?
It was going to be made of fiber glass and epoxy resin but I wanted to mimic the mechanical properties of the original P.P injection plastic. (so it can be twisted and bend out of and into place) so I made a few flat samples with different epoxy formula and messed a bit with fibers orientation as I was making the mold. Then with each prototype I kept refining the mold to V3 and lamination process 'till all the details and features like flanges, locator tabs, lock clips, trimming lines get molded/ laminated at once.

Here is a couple of pics to spice thing up :LOL2: ......

Well maybe not!
Insert image not working today :cnfsd:

[Carbonized]

New post and insert pic works :doh:

Mold V1 in the making.

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V2 starting to add details

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V3 more details, the lock clip now has a small bump stop built in, the locator flanges next to the center lock clip have self aligning bevel at there edge so this "should" be a one hand install and more little things to make life easier or at least try.

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The real thing, proto#4 with all the goodies molded in one shot.

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After trim

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Almost there!

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:dance1::dance1::dance1:

787178727873787478757876

[timsrv]

Impressive. You must be retired and/or have lots of extra time :wnk:. FYI, I used to make these type molds/mock-ups for a living & can still do it, but rarely do because it's so time consuming.....and messy. I still have boxes of sheet wax of varying thicknesses, clay, ultracal tooling plaster, hemp, the list goes on and on. I think it's been almost 15 years since I did a project like that. It's hard to justify for single use, but, now that you have the mold, why not go into production??? I bet you'd be able to sell at least a dozen of them :yes:. Tim

[Carbonized]

:LOL2: I wish I was, even if I am getting closer to that age every day, I'm afraid I never will be able to. But that's OK. I'm self employed so I can steal a couple of hours from the boss here and there :rol:. Some of us spend a lot of time at the local U-pullit :wnk: This is my preferred battle. I work in a atmosphere controlled clean room for the most part so nothing gets really messy, for the messy stuff I move to the dust and fumes area, mostly the finishing part, sanding and painting. One thing you are right about is how time consuming this kind of work is. The 1st picture of the mold in making was taken on November 18 th so the project was spread over almost 3 months, now the frightening part is this:

6597


These are my notes during the lamination of proto#4.:dizzy: I do not know what is the going shop rate over in the great North West, but I know what it is here. Granted I could shave a bit of time by making them in batches but look at the line that say trim (it should also say, seal and prime.) I cannot see how I could reduce that without modifying the mold one more time. Then it is still just a fancy looking chunk of Styrofoam that already has 4 pulls on it so maybe 5 or 6 more with great care and luck. I would love to be the one to bring a solution to this problem but I think we should not take our eye off of sheet metal: all riveted aluminium?, or maybe 3D printing ?

[timsrv]

Lol, if you charged going rate for labor and materials that would easily be the world's most expensive partial Toyota Van fan shroud :rol:. I do understand though (your affliction) as I have the same problem when it comes things like this. I just wish I had more time to lose myself in these sorts of projects (it's satisfying). Good job :yes:

[Tan Van]

Totally unreal !!! I'm just gonna work with some aluminum roll-flashing, screws, and aluminum tape... I will definitely make it "sanitary", but nowhere near as pretty as yours.

[Carbonized]

Thank You. The best thing about it is that it flex, twist and bend very much like the plastic part. I wasn't sure I could fool the epoxy into doing that, so that was fun. I already used the trick in the repairs of some vintage parts for expensive red Italian cars.. I'm getting some return on investment :thmbup::LOL2:


I'm just gonna work with some aluminum roll-flashing, screws, and aluminum tape...


Why not? I would use rivets. Any thing that could come undone around a spinning fan and running belts..... I don't know..:wnk:

[Tan Van]

rivets , or something like a dzus fastener, or tiny machine screws with washers and nuts ... sanitary and removeable should be the focus

[isaiah44]

Has anyone modified a 2wd fan shroud to fit in a 4wd van? My 4x4 is without a shroud, but I located a 2wd one. Hoping to make it work! Thanks!

[Carbonized]

The 2 radiators are of different size. Due to the location of the AC condenser the distance between fan blades and radiator is different. The 2WD is mounted tilted the 4WD is not. The 4WD shroud's bottom has to accommodate the front axel and diff. These two shrouds are so different maybe you should consider starting from scratch out of tin or roofing aluminium . Vanco has a good write up on doing just that somewere here.


Here are the two bad boys side by side. 2WD to your left 4WD to your right. If you manage to do it PLEASE take a lot of pics and post, There are a lots of us in the same situation
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[isaiah44]

Awesome, thanks for the info. I'll look into both options.

[whatvan]

Started this little project last night with help from the boys at Sheet Metal Fab in Ketchum. First version is steel. It went much easier than expected. We may take another go at it with aluminum, but a little trickier to weld.

Installation is a little tricky, but what isn’t in these vans. And she slides right out for removal. Test drive showed better results than without, but the heater core behind the bumper still looks necessary for the Idaho summer heat.

Its not the fiberglass/resin solution that looks cool as hell, but this did only take an hour and a half.

I’ll post pics when it’s finished and painted as well.

91329131

[Gambit]

Very Nice! A few more raw pics would be awesome as well, I know there are a few of us who still need to fab something up.