The Stovebolt Site Forums The Shop Area Engine Shop maiden voyage...FAIL

Way too long a bad story to detail here, but the final nail in the coffin was all the coolant pouring out of the radiator. The fan chewed through the core at the bottom 1/3 of the fan's diameter. Towed home by AAA.

I had the radiator rebuilt by a recommended shop. Did they screw it up?
When I sight down the sides of the inboard surface, where the core attaches to the wings, it's uneven, with a wider space at the top and a very noticeably narrower gap at the bottom, so that the radiator seems to tilt inward at the bottom.

But I've also read that there are two water pumps used on these 235's, and that one is significantly thinner than the other. My power plant is a combination of two 235's to get one running engine. I don't think so, but it's possible one had that narrower pump.

Note: it was also running at the very top of the normal temp range for the entire trip.

Anybody else had this experience? Or can report that their radiator also has a narrowing space where the core attaches to the wings? Or have any other insight??

Thanks.

What year truck?

What years for the 235s?

What year water pump?
What year fan blade?

What year radiator?
What brand and part number (a link to an on-listing would help)?

A later-year 235 in an earlier year truck poses a variety of problems/considerations. This topic is one of the common topics that owners have to deal with.

Sorry.
'59 235, correct engine (same #'s as original block)
Water pump and blade are original.
Radiator came out of the truck as I got it, was taken to a shop for rebuild but they said the core was beyond repair, so they got a new core out of some outfit in L.A. and welded it to the original ears.
It bolted right up, no problems. And I'm quite confident the fan wasn't making contact until I was at speed on the road. Sure didn't notice any problem the few times I started it up in my garage. But the fins are trashed now, clearly from fan impact.

Sounds like bad engine mounts. Have seen more than 1 radiator damaged when an engine moved forward under braking.

If it was OK in the garage, then either the radiator moved backward (body shifting on the frame) or the engine moved forward (motor mounts didn't hold it in place).

As you probably know, front motor mounts for this truck are hard to come by. They were missing when I got the truck, and I got these from someone here on the forum. I'm confident they're correct for the truck.
So, bad installation or ....?
How does one diagnose and fix something that can only be witnessed when underway?

I don't remember ever seeing a radiator in one of those trucks with a tilted radiator core. It's possible the side mounts were attached to the core incorrectly, but the time to correct that situation would have been before the fan got into the core. I doubt that you'll have any claim against the radiator shop, but it won't hurt to try to get them to correct their mistake after the fact. If the motor mounts are in good shape, a gap of 1/2" or slightly more between the fan blade and the core at the closest point should be enough to prevent any contact. How about the mounts at the bellhousing? The fan blades being closer to the core at the bottom tells me you've probably got deteriorated or missing mounts at the rear.
Jerry

The rubber parts of all mounts are new.
I'm wondering if I didn't torque front and/or rear mounts down enough. I don't remember seeing any spec in the manual.

Do a Google search for 1959 Chevrolet Truck motor mounts and you'll find tons of new mounts. You can get just the rubber pads or the entire kit. Compare your mounts to the on-line images and see if they are correct.

Also check your fan to see if you have a cracked blade that flexed into the radiator at high speed...

Mike B

More inspection = the radiator is clearly tilted inward at the bottom.
Measure from the back edge of the wing to the back edge of the radiator and it's 1/2 " at the top and 1.25" at the bottom.
It's difficult to measure the fan clearance but distances are close to the reverse, that is, <1/2" at the bottom and >1.25 at the top. And that's with smashed fins at the bottom.
Shouldn't the fan and radiator be parallel at every point?

I'm wondering how much flex there is in the fan at speed. In the garage rpm is low whereas at 55 mph there might be enough flex to produce contact.
eh?

Thank you for helping me think this through. I need a new radiator, but if that's not the problem I'll eventually be buying a third!

Try jacking up the front axle one side at a time, to see if the radiator/fan clearance changes due to frame twist while encountering non-level terrain. Just put a floor jack under one side at a time even with the spring, and lift that wheel a few inches off the ground. You'll be surprised at how much the frame flexes and how clearances change.
Jerry

I can't speak about a '59, but on the '48 the mounting flanges on the sides of the radiator are on an angle. About an inch off vertical from top to bottom. That is because the radiator support is not vertical, it leans. It is much easier to see when you have all the sheet metal off and the radiator is alone on the frame.
The support leans to the front (or back, can't remember) and the radiator flange leans the other way so when they are bolted together the face of the radiator core is vertical and parallel with the fan.
Possibly the radiator shop reversed the angle when they soldered them on?

This is a small problem with a big expense. As said already you have to figure out, by looking at another stock 58-59, what is wrong. Take measurements and pictures. Glendale swap meet, the car show out there on Sat's or Pavillions. Then decide if it's you or the rad guy and too think of a core. Did you move out of AZ yet?

May sound crazy but just to see what happens how about starting the engine and WITH THE BRAKES ON have someone put it in gear and under a "load" watch to see what the engine does....raise up, want to twist to one side..... if the fan missed in the garage something moved. Were all nuts on all motor mounts?