Fan Shroud on '69 C10?

[Pelon916]

Hi...

I'm a new member.

I just got a 1969 C10 Fleetside with a 305 with a 2 barrel carb and a turbo 350. I didn't build it myself, it was mostly done at the time of purchase. I will be adding on to it for sure.

My question is this... do you guys use fan shrouds?
The truck has a flex fan with no shroud. I am getting mixed input from different sources, some of whom do not ever use fan shrouds, some of whom swear the truck is doomed if I don't install one pronto.
I drove today in 100 degree weather, literally at a dead stop for 15-20 minutes in traffic and the temp guage (which seems to be working fine) never went above the middle. It usually stays just above C but in the dead stopped traffic it slowly rose to the middle and stayed there.
I guess I'm wondering if I should install the stock shroud and be done with it, or maybe install a nice electric fan that I can use when there is traffic. Also, would it maybe help to put a 160 degree thermostat? I'm not sure what it has at the moment.

Anyway... the truck isn't much of a hot rod, I just want a reliable, fairly good gas mileage, solid runner, which it definitely is at the moment.. I'm just trying to keep it that way!

Thanks in advance for any insight...

I'll post some pics soon!

Pelon-

[hughnews1]

go to the junkyard and find one ... I paid $10 last sunday for my v-8 350 ... F S .. yes put it on

[Pelon916]

do you run the stock fan or a flex fan?

[hughnews1]

i have stock fan

[chevykid1969]

If anyone has a shroud they want to sell im intrested. I have th find one for a firend

[BIG ORANGE]

Well first off Welcome to the board,2nd I for one belive in a fan shroud and I would put the correct fanshroud on that 69 you have she deserves it,besides click on to the 67/72 part board next door and place you a wtb thread and someone will come to your aid,sorry at the moment I'm out of them or I would hook you up.lol

[1972ChevyGuy]

I like my shroud too, its a home-made job though, the original one was a bit too short after i converted to a serpentine so i left the old one on and cut a peice of aluminum and pop riveted the thing to the old shroud, it keeps my engine @ 190 all day idling in 100 degree summer weather. During the winter i had to tape cardboard over 1/2 of my radiator though because it was pulling so much air it stayed sluggish and would never warm up fully.

[Pelon916]

thx folks!

so I will go ahead with my plan to put a stock fan shroud.
nobody uses electric fans?

[Longhorn Man]

Electric fans are OK, and some ppl swear by them, I would never fully trust my truck to them though...seen too many front wheel drive cars blow head gaskets and the owner say "I didn't even know my fan was dead".
Also, I would remove that flex fan and toss it in the garbage. They are not safe. THe fan blades get weak and break off. When that happens, they will cut through the hood braceing, the hood skin, and ayone in the way.
I've seen it happen myself, and another member just had it happen to them a couple weeks ago.
Yes, GM used to install them, but there was a re-call on stock flex fans.

As for your original question, yes, they are supposed to have one, yes, they work, but if your not overheating...and your testing in 100 degree temps...who cares if it has one? Myself, I'd ditch the fan, get a good clutch fan, and call it a day.

Is that a chevy 305 v-8, or a GMC 305 V-6 you have in there?

[Pelon916]

it's a chevy 305 v-8.
i'm not sure what cam he put in, what rear end it has or much else.
i do know it used to be a 3 on the tree before he put in the turbo 350.
i guess it's setup for a floor shifter, but for now it is on the column still. the linkage is kinda sloppy, but it works.
i'll probably leave it on the column since my daughter will ride in the middle.
i'm pretty new to the mechanical workings of cars in general, but i'm learning fast.
i will be doing all of the work on this truck myself with the help of some good friends who are professional mechanics.
when we took it for a test drive one of my mechanic friends couldn't believe that it was a 305, he thought it had the feel of a 350, even with the smaller carb. it jumps when you tap the gas pedal.
i got the truck for 1900.00 with all new tires, 15x8 chevy rally wheels, less than 1000 miles on new motor and tranny, new carb, new starter, all new pumps, HEI, and a brand new bench seat.
All the guages work and it fires right up every time i start it.
It's the exact year I've always wanted and after some new paint and wheels it will look great. The body is straight.

Is the 305 v8 a good one? My friend has one in his Chevelle and he likes it.

[Longhorn Man]

The 305 is a pefectly fine engine...but it is the Rodney Dangerfield of popular small blocks. It gets absoulutly no respect.
It came about becouse of tougher MPG standards brought on by the feds, also emmisions standards, and even the insurance companies whining too.
However, if your not out there racing, or doing much towing, then it will do you just fine.
It feels strong becouse it probably has 3.73 gears in the rear which is way more than most everything made in the last 20 years.
Welcome to the board and have fun!

[BubbaGreen]

Loose the flex fan......
Get a proper fan with a thermal clutch...and install a shroud.
The fan should be approx 2/3 into the shroud, to provide max
effect.
Flex fans have a history of letting go, flatten out during hi-way
speeds and actually restricting cooling. Another bad thing about
having no shroud, fans eat fingers quite easily, and you may
never think about till its too late. GET a shroud.....
Several versions were made...ones for BigBlocks (BB)
ones for Small Blocks (SB) and ones for the V6 version...
Take a few measurements of what you have to work with...
The V6 and the BB versions might be a bit difficult to come by,
but the small block versions are readily available. The SB
opening is approx 19" (I think) and the BB/V6 versions have a
21" opening. ONly real difference between the V6/BB is the
BB has a bit deeper depth, like an inch or so...would have to
measure to be exact.
But NO MATTER WHAT, installing a shrould will improve cooling
immensly.

[Nova_Cobra64]

I guess I would have to say that I am one of the members of the no shroud club. Wheather it is a good thing or not I don't know.
The hottest the truck has gotten was 190 last year with a leaky four core rad. I now have a new 3 core and haven't gone above 185. I don't do a whole lot of city driving though. On the highway it holds a consistant 175.

[Pelon916]

can you guys recommend a brand or model for the fan with a thermal clutch?
also, how much should i expect to pay?

[COBALT]

Check Summit Racing for the fan/clutch.

A word on heating/cooling. First, these small blocks run better hotter than cooler: 190 degrees or so. Normal operating temp should be about 1/2 way up the temp gage (needle standing up), or just left of that. The first mark on your guage is supposed to represent the thermostat opening to let the coolant to pass through the upper radiator hose. That's when your truck is "warm", but not at operating temp.

Second, make sure your thermostat hasn't failed in the open position. With a clutch fan and fan shroud if the truck's operating temp stays at the first mark all the time then your thermostat is stuck open all the time. If your thermostat failed closed then your engine will overheat plain and simple.

Third, make sure your thermostat is rated above at least 185 degrees. I run a 195 degree thermostat, and I can really tell a difference. To tell you'll have to peak at the top of the thermostat, which means you should probably just change it anyway.

If your temp guage is going to the middle when stopped, then dropping back down to the first mark while driving (and you don't have a shroud or a cluch fan) then I'd be suspicious of that thermostat. It's supposed to help regulate temperature.

[Earl Junior]

Since I'm still having troubles keeping the Cad motor cool (the thermostat has been replaced) I'm thinking of switching up to a clutch style fan. Besides, I need to ditch the flex fan.

If I upgrade to a clutch style, don't I need to run a reverse style water pump? I'm not sure why, but I thought this was a requirement and is the main reason I haven't upgraded already.

Just to be kicking ideas around, I'd probably use this clutch with this fan.

[BubbaGreen]

You dont need to reverse the fan...but if you get a thermal
clutch and fan from a salvage yard...you need to make sure
you get it from v-belt system and not a serpentine system.
Most serpentine setups drive the water pump and fan in the opposite direction of a v-belt. Also, measure the fan diameter
in regards to your current opening in the shroud.
I went to a 305-V6 fan shroud (its almost the same as a BB shroud, only not as deep) It has a 21" opening as opposed to
a 19inch opening found on the standard 350 shrouds.

As for highway driving....a shroud wont gain you much, If you
engine is running hot in traffic, the shroud will improve the
efficency of the cooling system. Also, note that the fan should
be approx 2/3" into the shroud, leaving approx 1/3 sticking out.
Another thing....if you have shroud and a flex fan together,
since the flex fans like to flatten out at higher rpms...it will
actually impede air flow.

If you have a Big engine, I am going to assume you have
installed either a 4-core radiator -or- a high efficency 3-core?

Might even want to consider going to an aluminum radiator.

[tom hand]

The middle of the gauge is where it should be... If it goes no futher I would not worry about it. My only question is when someone put the 305 in there did they put the long waterpump in there with it? If they did and it is in the stock V-8 location there would be no room for a stock cluch fan or should which may be why the flex fan is there in the first place

[COBALT]

No, it will fit. My 350 came out of an '80 truck and it has the long water pump plus 7 blade 18" fan plus the thermal clutch. It sits well within the shroud, but it fits.

[Pelon916]

well.. i got a fan shroud in today. i went back to the guy who built the truck and he had the shroud still. i'm not sure if it's stock (since the engine is a 305 i don't know what is stock or not), but it fits perfectly.
the truck hardly ever goes above the first line on the temp guage. the only time it ever did was when i was stuck in traffic on a 100 degree day.
i talked to the guy who built the truck about the cooling situation and he said that that radiator that's in the truck is bigger than the engine requires. I don't know if it is a stock radiator which is large in comparison to the smaller 305, or if he actually put in a larger radiator.
either way the truck seems to run really cool when i'm actaully moving.
i looked into a new temp gauge today, but i didn't buy one yet.
the truck is set up with an electric guage (stock dashboard guage) at the moment, and i don't know if i should switch to mechanical or not.
I am kinda worried that the guage just doesn't register properly which is why it stays in the cold area all the time.. and maybe it was REALLY hot when I was in traffic.
The truck wasn't pinging or acting funny at all, but it just freaked me out to see the needle moving in the temp gauge at all since it never goes above the first line, or just barely past it.
How common are problems with temp guages not registering the temp correctly?
Is there an advantage to electric vs mechanical temp guages?

And for the fan.. I just left the flex fan in for now. It fits perfectly in the shroud I installed. Do flex fans really restrict air flow at higher speeds?
I do have access to a free 4 blade fan of the same diameter if swapping them would be better.
I can also install a clutch fan, but the clutch I have access to is not a thermal one.
I can afford a thermal clutch and fan is they would provide the best cooling with the shroud.
I just don't know much about the whole topic.

Thanks again for your assistance.

[Shane]

I have a NOS GM shroud for sale - in NEW condition. It's for a small block WITHOUT A/C.

Email me if interested.

[jays68yak]

1. Welcome to the board.
2. Ditch the flex fan. I used one on my 68 lemans for a while, then switched to electric cuz I was only drag racing it. When I bought my 69 suburban it had a flew fan on it. How old I dont know. It gave way two weeks ago. After having the truck for about 6 months I have not been driving it much, so Im sure it would have happened sooner. Either way two of the blades broke off and one cut the upper radiator hose then landing in between the fender and inner wheelwell. The other one shot up to the hood dinging it and landed on the frame. Needless to say the shroud is shot now too, and the 5 mins that it was still running minus two blades screwed the water pump up. So far it has cost me: Water Pump $40, Electric taurus fan $30. Not too much but if there wasnt a $20 flex fan I wouldnt be out $70.
3. If you ware running a stock fan or a clutch fan I would use a shroud.

Good luck

[Long Knight]

Welcome to the board!