The Stovebolt Site Forums The Shop Area Engine Shop Fan, Water Pump and Harmonic Balancer

Hello all,

I have a 1953 I am working on and going back together with the engine I have found that my water pump is shot.

The engine is a 1955 235. So I purchased a water pump from Chevy's of the 40s which is the short shaft but requires a new fan due to the bolt pattern. (actual replacement is out of stock). I ordered and received a fan for a 1955 235 from Classic Parts today. Unfortunately, the fan blade hits the harmonic balancer... So what are my options?

Thank you All

Hello, Dad and Son,

Most likely, these are the parts you are trying to match up:
(if these are not your parts, please post links to your parts, or part numbers)

Chevs of 40s Short shaft water pump

Classic Parts 1955 fan blade
17 5/8"" diameter fan with 11/16" inch pilot hole. Fits 1955-72 6 cylinder and V-8 with short water pump. **(NOT FOR HIGH PERFORMANCE ENGINES OR FOR USE WITH THE SHORT SHAFT WATER PUMP)**

Here is the 47-53 fan blade
15 3/4" diameter fan with 1 inch pilot hole. Fits a 47-53 216 only.

What engine/year fan belt pulley will you be using?
- what width belt?
- what groove-widths do you have for your:
-- generator pulley?
-- harmonic balancer pulley?
-- fan pulley? (and, fan pulley-diameter?)

Maybe someone else can help you.
Since you have already bought your parts, it does you no good to be told that there were other ways to do this.

I had that issue when I put my truck together. I found a similar fan with less pitch, has worked well for a lot of years.

That is what I cobbed together in 1972, when I put a 1960 261 into my 1954 Suburban.

Leon (Leon's Auto Parts), "the walking man's friend", set me up with right-size fan-blades and the right-size pump-pulley. You do not get that knowledge and service these days.

Ok, I hve attached a pic of the setup...

I am using a 3/8" wide belt. with the 7" waterpump pulley and original harmonic balancer. I am using the standard Chevy Alternator with 3/8" pulley.

My thinking is to alter my old fan to work with the new bolt pattern as I cannot find the combination that would work correctly.

Anyone ever alter the old fan to work?

The bolt pattern can be slotted with a rat tail file to match the holes in the water pump, but the center hole MUST be a close fit over the water pump hub to allow the fan to run concentric to the shaft. If the hole in the fan does not match the hub diameter DO NOT attempt to drill or file it out. Any runout at all of the fan center will set up a destructive harmonic vibration that can result in fan blades breaking off at the center. Ditto for bending or trimming the fan blades- - - - -JUST DON'T DO IT!

I've seen some very nasty sheet metal damage and severe injuries from thrown fan blades.
Jerry

IF you can drill new holes that are concentric to the fan and those holes are not too close to other holes, yes you can modify. HOWEVER, it would be better to have patients and wait for more info from members, answer their questions and get parts that fit without mod.
Even if you have to buy correct water pump, you will be an expert after making this miss que. You will know that buying a part that is different than the original may set you back. I've made that mistake myself. The answer is: always study and ask the Stovebolt before you buy. That's why you joined, that's why the site is so popular. These members will save you LOTS OF MONEY.

I see I was typing while Jerry posted so I may be redundant.....and a slow typer

Almost anything can be done, and has been done to get an old Chevy going again. On my latest 50 3600 with the original 216 and probably original fan, I noticed the blades were cracked near the rivets that join the two pieces together. I only realized that when I replaced the water pump. I had a fan from 58+/- 235. And the center hole was too small to go on the shaft of the pump. So I fashion a simple jig to keep my hand drill centered on the existing hole and cut a larger hole with a hole saw. Worked great. As best as I can recall I did not have to drill new bolt holes. That was 11-12 years ago so I may have... I did have to tweak the blades slightly to clear the balancer, but other than that it all worked well.

Ok if I were to do this over and were to purchase a replacement water pump... what should I have done?

Use the original 1953 water pump with the water pump relocation plate made/sold by Pre '68 Dave.

This places the original style pump in the correct (1953) location for optimal cooling.

Use the 1953-55st fan and pulley

http://chev235guy.blogspot.com/search/label/Water%20Pump%20Relocation%20Adapter

This may not be easier for you, if you do not have the 1953 style parts (pump/pulley/fan-blade).

Does it make any difference if his motor is 55.2?

He needs to use the relocation plate and 1953 through 1955-1st water pump, etc for an engine 1955-1st and newer (in a 1953 truck).

1953 - 1955-1st belt and grooves were 3/8".

The OP has two problems.
1) His current parts do not belong together.
2) Even if they did belong together, they would still place the fan in the wrong position to pull enough air through the radiator. Whenever a TF or later 235/261 goes into an AD, it is best to go with the adapter plate which relocates the '53 water pump in the center of the radiator. An AD era fan will then work without hitting the harmonic balancer.

Thanks everyone.. however, my engine is a 55.2 235 so the original style pump for the 1953 would not fit.

I purchased this water pump from Chevy of the 40s

235 Water pump with 7" Pulley

Which fit well but the pulley and fan bolt holes did not align.

I really need this water pump:

235 Water Pump with original style pulley

But they are out of stock...

So I either need an original water pump or a fan that would work with the bolt pattern for the newer pump...

There is an adapter plate that makes the early design pump fit the later 235. That's what they're telling you- - -use the adapter! Dozens, if not hundreds of them are in use. By using the high-mount 216 style pump all the issues with fan clearance to the crankshaft balancer and radiator centering get solved.
Jerry

Why are you stuck on Chevs of 40's? There are other vendors out there. One of these pumps is probably what you want.

bartamos,

He has a 1955 engine that has a low-mounted water pump. It is either a 1955 car engine or a 1955-2nd truck engine. Both have a low-mounted, in the block, water pump (not shown on the page you linked-to). He needs a fan blade.

The pumps on the page you linked-to are high-mounted earlier water pumps for earlier engines. The only way he can use either of those pumps is to use the relocation plate/adapter. And, he would need the correct diameter fan blade (with 3/8" pulley). These would then be in the better/higher location as on earlier 235s and all 216s.

I think this Classic Parts short shaft water pump is like his water pump from Chevs of the 40s - it mounts in the later blocks (in the lower/non-optimal position). He would still need a correct diameter fan blade.

Confusing enough? (I hope I described these correctly).

By the way, I think the post you deleted had correct information in it.

I think I understood the parts needed to mount high, my post was just advising that the pump to do it is available at other vendors. Isn't the proper pump for the adapter shown on the page I linked? I was following up on your post, Carl and Jerry's post that advised on what to do, but he seemed stuck on Chevs 40's not having one in stock to be used with adapter plate? I'm probably mixed up now. Sorry.

BTW: Did Chev40 steal Dave's idea or is he supplying plate thru them?

My guess is they are reselling Dave's plate.
I hope he patented it.

Can you state which pump is to be used with the plate so one of us can delete any link to a pump that is not. Give a Classic Part number also please. Since we are advising to use the plate, we should not link to any other pump. I'm sure he knows, but for future searchers, it's best. I try to always say "or equivalent" after a vendor's part number so as not to endorse.

The two pumps on the upper left.

High mounted 1955-1st and earlier engines.

I too have the exact problem. I am putting a 1956 235 in my 1950 truck. The truck had a 216. I bought the same short shaft pump from chevs of the 40s. MY fan blade hits the harmonic balancer also.

Well, this sounds like an ongoing issue. Hope this does not step on any toes.

Don't see a tip regarding adapter plate method. I do see a tip from Stovebolt Engine Company/Langdons and another from Barry Weeks. Very well written.
I hope that Dave can write a tip for his method. No reason not to. He has shared it here already and everyone likes it. His method is cleaner and better for the reasons he describes.

Don't know if Langdons is in business and don't know if Dave's site sells them. The point is that members are buying parts that are wrong. If they don't search Stovebolt they don't know what's out there....or in here......or here within.

Dave's write-up (at his blog) is at the link in my third post in this thread. However, I do not see a "contact/purchase" link there.

An Internet search on "216 235 water pump adapter" comes up with several sources for buying the plate.

"Well this sounds like an ongoing issue"???
Seems so - it has been mentioned in over 900 posts since 2004.

so if we do the conversion plate which water pump do we use. The original long shaft for a 1956 235? or do you still need a short shaft?
I also read on that blog that the harmonic balancer from the passenger 235 will not work. That is where my engine came from; a Belair. now what?

evac34,

You have a 1956 235 car engine that you want to put into a 1950 truck?
You will want to use a pre-1955 water pump.

There are two styles of pre-55 water pumps to choose from:
3/8" belt groove or 5/8" belt groove

Will the 1950 truck be 12v?
If so, do you already have a 12v generator - what size/width belt-groove (3/8")?
Do you have a harmonic balancer - what diameter and what groove size/width?

With that information, maybe people here can advise you if your combination is OK.

I don't have the energy to endure searching Jim Carter's terrible website at the moment, but I can tell you I bought their short shaft pump and the fan they recommend with it, and had zero problems with interference on my late 235 in a 51 truck.

Here's the short shaft pump from Carter. The description references the fan part # you need to make it work

http://www.oldchevytrucks.com/cart/product.asp?prodid=REME205&i=19661|||||

There you go! I'm the perfect guinea pig for this stuff. I know nothing. I thought a newer pump won't work, so J. Carter pump says 37-62. I thought I was to get a 54 or earlier pump. See what I mean about putting this all together in a tip with a clear explanation as to which pump? which plate and which fan and how to modify a fan properly............ ??????? Short pump, earlier, later, 3/8, 5/8 pulley, harmonic balancer, install issues, sealing issues all can be resolved in one tip. With actual part numbers from todays vendors not original GM part numbers or earlier/later descriptions. Tim, you have given great info in this post. You have done this to two trucks. You are a good writer. With Dave's permission, his page can be linked in the tip. But not just his page, a complete no brainer tip. That even I can understand. I wrote to Dave and he says his plate is sold at several vendors. Awesome.

The J. Carter site is nicely improved. Well done. I tested it just now. At top of page I chose the picture that says 47-53. On the left margin, I scrolled to "Mechanical/ cooling system/ water pumps" Bingo! What could be easier than that?

Well, Jim Carter only has a few mistakes in that listing.

"1937-1962 Water Pump Short Shaft Style Chevrolet Pickup Truck"
1937-1962??

It works in/on a "1955-1962, 235 or 261 engine" that is to be installed in a "1937-1955 Chevrolet truck"

"Includes proper narrow 3/8 inch groove pulley to match that on the engine harmonic balancer."
The 3/8 in pulley was used from 1953-1955st older style engines.
The pre-1953 216/235 engines used 5/8" pulleys.

You can use a 3/8" belt in the 37-52 216/235s, but it will ride low in an original 37-52 5/8" groove harmonic balancer and it would ride low in an original 37-52 generator pulley.
Jim Carter sells a 3/8" belt for this water pump and application.

Jim Carter says this fan blade will work with his short shaft water pump.
This will/should have no clearance problems in the older trucks, but the fan blade will not be located in the optimal-cooling location in the older trucks.

Obviously, there is no need for Dave's water pump relocation plate with this water pump.

In this application, the belt wouldn't be riding in a 37-52 balancer. It would be on a 55 and up 235 balancer.

That '55 and up balancer would have a 3/8" groove.

Presumably, you have a 12v generator, with a 3/8" groove?

JC's short-shaft pump for use on later 235/261 engines installed in earlier trucks has a 3/8" groove.

A good match for the correct diameter 3/8" belt.

Tim

so i am putting a 1956 235 Belair engine in my 1950 truck. The harmonic balancer is 7 3/8" in diameter and has 3/8 pulley. I will put in either a 12v generator or alternator not sure yet. I called chevs of the 40s today and they told me the pump they sold me should have a shim with it. I tried shimming the fan blade out but it still hits the balancer. I am trying to re-use the fan blade from the 235 motor.
should I take the loss and order from somewhere else? what is the best way to go here. everything else was going pretty good but bam I hit the wall with this one.

Pre68Dave's page, liked by Tim, says do not use a passenger car balancer. Pulley should measure 6 3/4.

right bartamos; just re-measured. the balancer is 7 3/8" the pulley itself behind the balancer is 6 5/8"

Dave says: Caution: " I do not recommend using the 1955-62 passenger balancer since the pulley is larger and may turn the fan too fast, leading to cracking. (to identify this balancer, the pulley is 6 3/4" OD X 5/8" outside to outside edge).

USE:
1941-52 Harmonic balancer and water pump for ⅝" belt.

1953-54 Harmonic balancer* and water pump for ⅜" belt. "


I don't know if this address your S--- hitting the fan.

that is only if we use the adapter plate set up correct?

I used a 1953 235 Chevrolet car water pump 3/8" groove with Dave's adapter on my 1956 Chevrolet car engine in my 1951 suburban .
I know I changed the harmonic balancer as well , would have to measure it, don't remember the size of it.
rock auto water pumps

If he uses a long shaft pump , the radiator will have to be moved forward for fan/radiator clearance, if it already hasn't been done.

Tim

OK let's take evac34's question: You said what he can't do. So what can he do? Am I to understand that had a perfectly good car motor with no fan hitting problem, but to put it in a 1950 truck he had to get a short pump so the fan would not hit the radiator but now it hits the balancer? What does he need to do?

This is a total different question than adapter plate component problems I guess, but can someone address this situation first? It is pretty near the OP's first question.

There are enough bits and pieces on here and 900 other posts to get the plate thing done if a person reads enough. (Tip Mr. Lederman?)

This is THE major issue when putting a late 235 into the 54 or earlier Chev, more things come into play than just the water pump. Fan in wrong place (not where it should be for keeping cool), hit's balancer, hits lower rad outlet I've see all kinds of shade tree solutions. Best one is the adaptor plate and back to early pump, also could ditch the fan all together (which is in the wrong place now anyway) for a whittled down one or electric etc. This subject and solutions should be a tech tip on the bolt.