The Stovebolt Site Forums The Shop Area Engine Shop Need cooling fan selection advice...

Hi all,

I have a 1940 1/2 ton with a'53 235. After resolving some overheating problems with a water pump adapter, 6 blade fan, and a extender plate to get the fan a little less than 1/2" from the radiator (also adjusted timing and fuel mixture), cooling problem was solved. Apparently though, the fan was a bit too close and started to graze the radiator when I'd go over bumps (some of you strongly warned me about that!). Then on Wednesday I hit a big bump and my fan decided to dive into my radiator resulting in large holes, coolant spewing everywhere and my temperature gauge soaring.

Needless to say I'm on my way to get a new radiator today. I need some advice on which fan blades to use. I had a 6 blade with a steep rake angle (https://goo.gl/photos/9QyfFf5LbQUs7pvh9) which seems like it would move a lot of air but I remember some discussions that mention about the great air moving capabilities of the old, original fan blades (which I still have). I am a restorer not a 'rodder so original is always best with me.

Would you knowledgeable folks recommend a 6 blade or an old 4 blade?

And assuming I will not be able to find a shroud to fit a '40 with a'53 235 with an adapter and spacer.

And... How much engine movement is normal when goig over bumps?

thanks!

Doug

You need to take a close look at the condition of your motor mounts. You should not have a significant amount of movement. Also check your front clip mounting points, to make sure the radiator isn't moving into the fan.
A half inch spacing is plenty if everything is tight and secure.
Carl

Thanks Carl.

I had not considered the possibility of my engine moving around as part of the problem but it makes total sense given that my fan would graze the radiator when I hit the bigger bumps.

I took a look through some discussions regarding motor mounts and see that my '53 235 in a '40 may also have additional issues of fit and tolerance. I haven't figured it our yet but was wondering if you could take a look at these picts and give me your assessment...

Here is the front motor mount (https://goo.gl/photos/kkxDRqub24NTygEn9). Its hard to assess the condition as it appears to be in a box. I read something about the required tolerances (for '48-'51 but still trying to understand the tolerances from what to what and if it applies to me....: (The clearance between the retainer and the plate is critical and is described in this section of the 1948 - 1951 Chevy Truck Shop Manual. The clearance should be between 3/64" and 5/64" unloaded with mount installed. If the clearance is less than 3/64" the retainer should be filed or machined. If the clearance is more than 5/64" the retainer requires replacement.)

And the side mount (https://goo.gl/photos/C6UpM53Wk4tTXS2e9). I see lots of old, shrunken looking material on here but now I'm not even sure if its a motor mount.

I'll try and get a rear mount picture.

Thanks for any thoughts you might have.

Doug

Yup. Something is way too loose. Put a wrench on everything and maybe you will find the problem right away. Good Luck. Check the crossmember below the bellhousing, check everything. You will find it. It is not normal. The engine shouldn't move at all.

I am curious what year water pump you are using?
In looking at your photo bucket it looks like you have a 1955-62 engine, not a 1953.
You mention "water pump adapter", are you using my adapter?
In one pic it looks like you have a modified short shaft pump.

Hi Dave,

I believe I do have a short shaft water pump on an adapter plate to raise the fan on the radiator. (it may be your model). It was a few years ago but I remember reading that a "short shaft" would be needed in my situation.

As far as the engine goes, you may be right about the 55-61. I never fully sussed out the casting numbers with the many online guides to figuring the year. What was your clue that you base your hypothesis on?

I still have the old water pump - perhaps I should measure it to see what clearance I'll have without the fan spacer?

Thanks!

Doug

Here are locations of various codes.

Post your codes and people will help you ID your head and block.

Hi Deve,

With a little poking around I find that my front engine mount is not the is steel box and rubber mechanism as highlighted in Don2sea's 235 engine photo (https://picasaweb.google.com/down2sea/FrontMotorMountAssy#5084215542431577634). My mount seems to be just a plain block of rubber bolted from the engine bracket to the frame. I assume this is allowing movement.

Somewhere I read that I could also use a stock 216 front mount and not a 235 mount. I'll start looking for what those are and if mine is different. I'll also check all the engine mounts with a wrench.

Thanks for sharing your knowledge with me :-)

Doug

Doug,

The early 235s had the same front-mount as used on 216s.

Front-mounts were used on some later years (1954 and later high-pressure) truck 235s (maybe up to 1959? - someone will confirm/correct).

Some side-mount 235s/261 have a front plate that can be drilled for the front mount.

Finally got my new radiator from The Filling Station (2 months after ordering) and am thinking about fixing my truck. I have a few questions if anyone has any ideas:

1. To install a proper front engine mount, is there any way around pulling the harmonic balancer in order to get enough space to put the mount bolts in? Seems like there must be a "put the bolts in from the bottom" type of solution that someone has used.

2. Pulling the harmonic balancer... How is that best done? I assume there is a "puller" that is about the right size. I'm assuming 60+ years of being on there is going to be tough to dislodge. Any suggestions?

Other Motor mounts:

The side mount: Is this an engine mount?v(https://goo.gl/photos/k18mAuuT2uWP7KRm9)

(and if you want ta look at my sad rubber-only mount: (https://goo.gl/photos/c6gsygi3nUa9wyPc9)

Thanks,

Doug

Pictures of the front mount, bell housing mounts and the radiator support mount. Just so you can see them. Not an advert for any one provider:
http://www.classicparts.com/Motor-Mounts/products/871/
The bell housing mounts have 2 bolts to the bell and 1 to the cross member. If the bolts in the front are OK you can reuse them. If not a good puller will bolt to the damper pulley. Do NOT use a puller at the edge of the damper pulley. Damage to the pulley will ruin it. There are some threaded holes to bolt the puller to the pulley. Clean them out and use the proper bolts to attach the puller. It takes room to pull out, but you have the radiator to remove any way so should be alright. So you need 2 bell housing mounts, a front mount(4 parts) and a radiator support mount(2 of those on most trucks) Some early AD have a single radiator support mount in the center, but most have 2. Finding the other 2 bits for the front mount might take a bit of searching.

Thanks Steve,

Good references. Assuming the bell housing mounts are the "rear motor mounts" I didn't see any of the appropriate years in the link but will look around (or maybe the 47-53 will work since I have a '53 engine.)

I will make sure to get a bolt-in puller for the pulley and assume that it's the two holes, 180 degrees apart in the inner ring (https://goo.gl/photos/5GD664HvLcfohbKD7) that are the threaded holes.

Good to know about the Radiator support mount too - my old one did not have any mounts except the side mounting brackets.

Thanks again!

Doug

Yes on the pulley. Those are the proper holes to mount the puller. Yes as well on the Bell Housing mounts. They are the rear engine mounts.

I am planning (soon) to replace my front engine mount (in my '40 with a '53 235). I will pull the front pulley as instructed.

Is there a proper way/place to raise the engine from below so I can remove the old mount and put the new one in? I do not have an engine hoist (and my garage roof would probably cave in if I tried to use that:-)

Thanks for any advise,

Doug

You could jack the front of the engine by the oil pan rail. Stand a piece of 2X4 on end beside the oil pan, use a bottle jack or whatever you have that might work.

OK another issue - I was prepared to remove my harmonic balancer, etc to place the front motor mount & bolts in but I see that the front of my crankshaft is peened over and I do not think I will be able to get my balancer off.

I'm thinking there must be a way to bolt from the bottom, maybe weld nuts to the plate (where the square holes are?) that goes above the rubber block?

Has anyone done something like that? You think It might work?

Thanks - Doug

I have welded nuts on the top side and ran the bolts up from the bottom many times.

You don't even need weld nuts. You can just run the bolts up from the bottom. The engine or chassis doesn't care which end the nut is on. I would be more concerned with why your crank is peened over? That is a first for me.

Awesome! That is really good news. And am I correct that it is the top plate (that goes under the cover) that I would weld the nuts to?

doug

Jacking by the pan rail generally crushes the pan gasket.

That makes sense about crushing the gasket. Would you suggest an alternative approach that does not involve a hoist?