Chevy Nova Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
551 Posts
Discussion Starter #1 (Edited)
Is a short water pump a must for our Big Blocks?????

Hey guys, my motor came with a long water pump and today I tried to install my radiator with shroud and 16" fan and my fan overlapped the pulley about 1-1/2".

For us big block guys, do we all need to run a short water pump?

I am now trying to figure out the cheapest way to remedy this. I will either try to find a new shroud and offset dual fan system that might just barely allow enough space which tend to still be around $200, OR get a new short water pump, but this means now I need a full new pulley and bracket kit as well which is still going to be around $250-$400.

What the F. It never stops.

What would you guys suggest?

I did find this fan and shroud kit that might be exactly what I need to give me enough room for the water pump pulley to fit right in the middle there just above the fans.

[/url]Screenshot_2019-05-17 Chevy Nova Custom Aluminum Fan Shroud 2-10 Fans-17 H x 23 W eBay by ssnovass396, on Flickr[/IMG]
 

·
Registered
Joined
·
374 Posts
For a 70 BB, a long water pump is used along with a original style 3 or 4 core radiator, five blade fan with no spacer. Not sure what components you are using may have wrong fan and maybe incorrect pulley.
 

·
Registered
Joined
·
551 Posts
Discussion Starter #3
For a 70 BB, a long water pump is used along with a original style 3 or 4 core radiator, five blade fan with no spacer. Not sure what components you are using may have wrong fan and maybe incorrect pulley.
Here are my pulley's. What do you think? Are these not right?

20190508_144746 by ssnovass396, on Flickr
20190508_144801 by ssnovass396, on Flickr

I am using This Radiator https://www.coldcaseradiators.com/product/68-79-nova-big-block-auto-aluminum-performance-radiator

Here is the radiators specs.

Radiator Specs

Core Height 16.85 inch
Core Width 23 inch
Overall Height 19 inch
Overall Width 28.35 inch
Overall Thickness 3 inch
Tubes (2) 1.25 inch Tubes
Upper Hose 1.50 inch
Lower Hose 1.75 inch

The fan is very thick and the motor in the fan is what sticks out and hits into the water pump pulley.
 

·
Registered
Mike - 74 Nova Baltimore, MD
Joined
·
1,486 Posts
I did find this fan and shroud kit that might be exactly what I need to give me enough room for the water pump pulley to fit right in the middle there just above the fans.

[/url]Screenshot_2019-05-17 Chevy Nova Custom Aluminum Fan Shroud 2-10 Fans-17 H x 23 W eBay by ssnovass396, on Flickr[/IMG]
The shroud shown in the image looks very shallow and may restrict air flow thru the radiator while cruising.

Are you set on using an electric fan for cooling? Another option is to install a mechanical 7 blade fan with a thermal fan clutch (with the appropriate fan shroud).
 

·
Premium Member
Joined
·
901 Posts
Fan Clearance

Looks like your pulleys are correct, as do your engine stands and their placements. But if I'm not seeing the stands clearly, to be clear, the taller engine stand goes on the driver's side to allow room for the exhaust and steering box, the shorter engine stand goes on the passenger side. The spacers you placed beneath the engine stands may give you a future problem with driveline/pinion angles. The engine stands that you removed were small block stands.

You provided many photos. It seems you were also concerned with the engine stands, but you did not mention the issue(s).

It looks like you are concerned with steering linkage hitting your Moroso oil pan. Moroso does make a pan, of excellent quality, that does not pose steering linkage problems.

Did you misspeak when you said your "Fan Motor" was causing a problem?

You will only be able to employ a clutch fan if you have a short water pump and all the belts, pulleys and brackets the short pump will require. I've found that your cost estimate of up to $400.00 is a good estimate, but as you have found, the price of every project is higher than the original estimate. CVF Racing has long and short water pump pulley and bracket "kits" made of billet aluminum that are of the highest quality and are at competitive prices.

If you have the correct GM/OEM fan shroud, it will have a 20 inch opening, so your fan can be up to 18 inches in diameter, allowing 1 inch of clearance.

Some pictures of the fan/radiator components and interference would likely shed light on your issues.
 

·
Premium Member
Joined
·
31,194 Posts
I’m not trying to poke at anyone, but the factory setup works quite well in The BB Nova, plus everything is readily available.

68 is the only year for the short water pump, and alternator on the driver side.

I run a Camaro 4 core BB stock replacement rad, factory shroud, repop BB fan, with a 160°F thermostat and I can drive all day in traffic in 90°F weather, with my engine never exceeding 180°F. It you’re looking to save weight, go with an aluminum replacement rad.

The Camaro came with BB and AC, so they offered a larger rad than the BB Nova.

There is a misconception that mechanical fans eat up an excessive amount of horsepower, because testing can only be measured accurately on a dyno. The problem is the fan is trying to pull the engine forward while it’s being held stationary, which increase the drag reducing power. As soon as the engine is moving forward that drag cancels itself out. The factories have gone to electric fans to help increase mileage, because vehicles are able to maintain optimum operating temperature without a the drag of a fan at speeds of 40 mph and up. It also allows the engine only use the fan in colder climates only when needed allowing vehicles to get to optimum operating temperature sooner.
 

·
Premium Member
Joined
·
901 Posts
Numbers?

Mr. Moderator:
Please provide your fans GM part number and a description of your fan. Does it have five, six or seven blades? Does it bolt directly to the water pump or are you using a spacer. Are you using a long water pump or an electric water pump. You did not mention a fan clutch, but if you are using one, please include that number also, as well as a description of your clearances.

Thank-you
 

·
Registered
Joined
·
551 Posts
Discussion Starter #8
Mr. Moderator:
Please provide your fans GM part number and a description of your fan. Does it have five, six or seven blades? Does it bolt directly to the water pump or are you using a spacer. Are you using a long water pump or an electric water pump. You did not mention a fan clutch, but if you are using one, please include that number also, as well as a description of your clearances.

Thank-you
Okay, let me explain more in detail. I have the zz454 GM Performance motor. It comes with the long water pump. The water pump pulley sticks out about 1-1/2" into where the electric fan would be. See pic.

20190520_134123_fx by ssnovass396, on Flickr
20190520_134130_fx by ssnovass396, on Flickr

Going with my old clutch fan is a no go at all. I got a very nice performance large CoolCase 2 row 1-1/2" tube radiator. The clutch fan is easily 2 or so more inches longer. The larger 16" fan in the center with a large fan motor overlaps about 1-1/2" over the water pump pulley.

20190520_134209_fx by ssnovass396, on Flickr

I found a way to remedy this hopefully. I have two options. I can either get a short water pump which will pull the whole system back 1-1/2", but then I will need to get all new pulleys and brackets which will cost me easily $450 which I did not account for at all on this project. Or I can get a dual 10" offset electric fan system like so.

Screenshot_2019-05-17 Chevy Nova Custom Aluminum Fan Shroud 2-10 Fans-17 H x 23 W eBay by ssnovass396, on Flickr

I need it to be offset so that the driver side fan won't run into the power steering pulley bolt. This pushes the fans just enough out of the way for the water pump to not hit anything in the center and to potentially work. My current shroud is also pretty thick at 1-1/2" extended out from the already pretty thick radiator.

20190520_134058_fx by ssnovass396, on Flickr

So here is a mock up using the 16" fan in the new offset positions. Keep in mind the new shroud will be slightly thinner and the 10" fans will also be thinner at the ends.

Driver side top fan

20190520_134234_fx by ssnovass396, on Flickr

Passenger side lower fan

20190520_134342_fx by ssnovass396, on Flickr

I am really crossing my fingers this will work. For only about $150 this might save the day and if it doesn't then I guess I will just have to bight the bullet and switch everything out to a short water pump setup.

I hope this helps you guys to understand my situation.
 

·
Premium Member
Joined
·
901 Posts
The Long and Short of it.

Bobcatman suggested a fixed mechanical fan, as did Moderator Taz3. I have been using an 18" six blade FlexFan for over ten years. My cooling problems disappeared with an aluminum radiator with large tubes. The Harrison Big Block radiator allowed the temperature to steadily rise at idle.

I continue to investigate mechanical fans.

I tried to install a seven blade clutch fan and stopped when I saw that I would need the short water pump, with matching brackets and pulleys.
In fact, the deciding factor was the fact that my Edelbrock water pump cost over $300.00. It works fine and $300.00 is not a sum I want to put on a shelf, and into storage.

Also, there are people that complain that the short pump throws belts. Not everyone, but some.

I think you have done a lot of homework trying to make the electric fans work, and they may be the answer. An electric water pump would solve some problems but present new issues.

Another big block is present in your photos. If you had it in your Nova, what set-up did you use to make it work? If it worked, the same set-up will work on the new engine.

I have no doubt you will finish this project successfully.
 

·
Registered
Joined
·
551 Posts
Discussion Starter #10
Bobcatman suggested a fixed mechanical fan, as did Moderator Taz3. I have been using an 18" six blade FlexFan for over ten years. My cooling problems disappeared with an aluminum radiator with large tubes. The Harrison Big Block radiator allowed the temperature to steadily rise at idle.

I continue to investigate mechanical fans.

I tried to install a seven blade clutch fan and stopped when I saw that I would need the short water pump, with matching brackets and pulleys.
In fact, the deciding factor was the fact that my Edelbrock water pump cost over $300.00. It works fine and $300.00 is not a sum I want to put on a shelf, and into storage.

Also, there are people that complain that the short pump throws belts. Not everyone, but some.

I think you have done a lot of homework trying to make the electric fans work, and they may be the answer. An electric water pump would solve some problems but present new issues.

Another big block is present in your photos. If you had it in your Nova, what set-up did you use to make it work? If it worked, the same set-up will work on the new engine.

I have no doubt you will finish this project successfully.
Thanks for the encouragement. Yes I pulled out an old 70s Gen IV 454 and absolutely everything is different trying to put in a new Gen VI. The old motor used the clutch fan and it had the original straight six super thin radiator. This things was like 1/2' thick. I was having heating issues and the clutch fan literally touched the radiator and bent in the fins slightly so that it no longer touched. So, its just a big motor in the small Nova compartment. So I will see if this will work with the electric fan and shroud. You guys could help me with something else.

I need to know if this shroud will work for my radiator. I want to know your thoughts.

https://www.ebay.com/itm/Chevy-Nova-Custom-Aluminum-Fan-Shroud-2-10-Fans-17-H-x-23-W/282941150324?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=e6b5d50566184f0cbb4a43a54ac643b9&pid=100675&rk=2&rkt=15&mehot=lo&sd=263878875253&itm=282941150324&_trksid=p2481888.c100675.m4236&_trkparms=pageci:2a5e0dcb-7b5e-11e9-a56b-74dbd180b148|parentrq:d7c2533f16a0ad78ab1e4aafffb8ee18|iid:1

Here are the specs.

Made to fit DPI 412
Holds 2-10" electric fans
Dimensions 17"H x 23"W
Shroud: Custom/Aluminum
Overall Height: 18.75
Overall Width: 29
Fan Size: 10 Inch
Fan CFM's: 1900 CFM's Total
Part Fitment:


And here are the specs for my radiator/shroud

Height = 17-1/4"
Total height with top lip 18-1/8"
width 22-13/16"

Now these are exact, but on the radiator website it rounds up to.

Core Height 16.85 inch
Core Width 23 inch
Overall Height 19 inch
Overall Width 28.35 inch
Overall Thickness 3 inch
Tubes (2) 1.25 inch Tubes


https://www.coldcaseradiators.com/product/68-79-nova-big-block-auto-aluminum-performance-radiator
 

·
Registered
Joined
·
150 Posts
What is the measurement from the core to the front of your pulley/pullet bolts?

What is the thickness of the core with that radiator?
 

·
Registered
Joined
·
551 Posts
Discussion Starter #12
What is the measurement from the core to the front of your pulley/pullet bolts?

What is the thickness of the core with that radiator?
Overall thickness of the core is 3"

I didn't get the measurement of the space between the core to the pump pulley sorry.
 

·
Premium Member
Joined
·
901 Posts
Fitment

On Ebay I looked up the shroud with two fans that you are looking at.
The fitment section told me that it would not fit my car. I too have a "69 with a Generation VI engine.
I recommend you call in the experts, either the fan shroud manufacturer, or the tech help of other manufacturers or suppliers. I have found Summit's tech help to be excellent, and if what they recommend does not work for you, they will take it back and continue to work with you.
In one instance for myself, Summit took back a Milodon oil pan and and located a Moroso pan and pump that fit perfectly.
 

·
Premium Member
Joined
·
31,194 Posts
Mr. Moderator:
Please provide your fans GM part number and a description of your fan. Does it have five, six or seven blades? Does it bolt directly to the water pump or are you using a spacer. Are you using a long water pump or an electric water pump. You did not mention a fan clutch, but if you are using one, please include that number also, as well as a description of your clearances.

Thank-you
I’ll have to look up part numbers. My mechanical water pump is a long style, no spacer, the five blade reproduction fan bolts directly to the pump and I do not use a spacer. I do have the original GM BB shroud and my fan is approximately 1/2-3/4” away from the rad. I’ve also used a seven blade fan successfully, I want the original look of the 5 blade though.
Everything is either original L78 parts or reproduction L78 parts, except the rad. The rad is the larger 4 core, rather then the original 3 core.

Fan https://www.ebay.com/itm/1969-70-Chevrolet-Nova-L78-396-427-Factory-Fan-Blade-Rare-/271312127232
 

·
Premium Member
Joined
·
901 Posts
From Moderator TAZ:

I’ll have to look up part numbers. My mechanical water pump is a long style, no spacer, the five blade reproduction fan bolts directly to the pump and I do not use a spacer. I do have the original GM BB shroud and my fan is approximately 1/2-3/4” away from the rad. I’ve also used a seven blade fan successfully, I want the original look of the 5 blade though.
Everything is either original L78 parts or reproduction L78 parts, except the rad. The rad is the larger 4 core, rather then the original 3 core.

Fan https://www.ebay.com/itm/1969-70-Che...-/271312127232
-----------------------------------------------------------------------------------------

Yikes, The Five Blade Fan Is Real Money.
The GM number is included in the Ebay posting, 3939001.
It is ChicagoLand reproduction for only $239. Originals can exceed $1000.
When I bought my Nova in 1999 for $1000, I thought I was buying an economy car with great parts interchange ability. Now the thing is transforming into a large chunk of unobtanium.
 

·
Registered
Joined
·
551 Posts
Discussion Starter #19 (Edited)
I pulled the trigger and ordered the offset style shroud and fans.

These don't come with the screws and hardware to bolt the fans to the shroud. What screws or kit do I need? Is it as simple as a screw and nut on the other side, or do I need to get more fancy with a threaded insert like I am seeing on the Cold Case radiator shroud?

Can I even just use the common zip tie method through the shroud and through the radiator?

Or maybe its as easy as just going to the local ACE can pickup up a few screws, washers, and nuts right?
 

·
Registered
Joined
·
551 Posts
Discussion Starter #20
For those of you that are interested, I have the answer for my initial title question. I kept the stock zz454 long water pump, I kept all the long water pump pulleys, and have a super thick 2 row (Same size as a large 4 row) with thick shroud and with the offset dual 10" fans it works perfectly. There is about an inch between the fan and the water pump pulley. You will need to go with the offset where its higher on the driver side because the power steering pulley can interfere with the fan motor. So having the fans offset moves the driver size fan up and out of the way with miles of room. Have a look.

I went with the shroud from ebay here. https://www.ebay.com/itm/282941150324?ul_noapp=true

It came without the screw holes and no hardware. So I got a bolt, lock washer, and lock nut and it worked perfectly and looks okay to me.

Had to drill my own holes and the cool thing was they are now doing the louvers in the corners.

20190524_145559_fx by ssnovass396, on Flickr
20190524_150246_fx by ssnovass396, on Flickr
20190524_153124_fx by ssnovass396, on Flickr
20190524_154801_fx by ssnovass396, on Flickr
20190524_154805_fx by ssnovass396, on Flickr
20190524_154812_fx by ssnovass396, on Flickr
20190524_154816_fx by ssnovass396, on Flickr
20190524_154833_fx by ssnovass396, on Flickr
20190524_154852_fx by ssnovass396, on Flickr

I am very happy with this setup. So originally I was fearing I would need to now get a new water pump and fully pulley kit which would run me around $700 out the door. Instead this offset setup cost me $140. Heck yeah!
 
1 - 20 of 23 Posts
Top