That is excellent work! And what a beautiful truck. You sure dont see many of them. Thanks for all the pics.
Well the truck made it home: As I've come to discover, these trucks and the 6 cylinder "conversion" are prone to overheating issues. The engine is a 55-57 GM, as per the casting number.. When the front end (core support) was shimmed to correct the hood gaps, the fan interfered with the lower neck. After t*******, it left this.... And as you can guess, it overheated on the way home. Supposedly there is a relocation kit to raise the water pump up higher on the front of the block, but I need to know if this is the correct water pump and pulley to use with that kit, or do they need to be replaced. We are going to pull out the radiator for a pressure test and likely recore. The fan will be swapped out for a 15" model (providing that fits ok...) So can any of the 6 cylinder guru's familiar with this kit tell me if I need a new pump/pulley or is what we have compatible? Oh.....and something else needing some buffing touch-up when that is done...
That turned out really well! Beautiful truck and the buff really makes a huge difference! I have a question about buffing and paint finish, if you don't mind. I have a car with a quality black base/clear finish. In artificial light it looks flawless, in indirect sun it looks flawless, but in direct sun you can see machine marks/swirls. Do you think one more glasing buff would take that out? I don't want to get carried away and ruin what otherwise is one of the best paint jobs I've ever had. I've tried 3M glasing by hand and it didn't help, but didn't want to go to a more agressive compound. Thanks. I don't have anything to add about the overheating issue, other than it looks like it really needs more fan or some kind of shroud so the fan can pull some air through the core.
I got to thinking about the cooling system and had an idea, though I may be barking up the wrong tree. Is the system pressurised? My 36' Pontiac had a non pressurised system and the block had drilled rods in the water jackets to spray water on the cylinders. If the GMC still has the factory system, it may not be pressurised, but the 55-57 block was probably designed for a pressurised system and most likely won't have the right water flow characteristics to work with a non-pressurised system. Does that make sense? I really don't know much about early GMC trucks, but was thinking this could be the problem.
I believe it does still have the non-pressurized system, which is likely adding to the issue. Then if we do convert it to pressurized while recoring a radiator, the chrome radiator cap will need a pressurized cap adapted to it as well. I never get the easy ones..... On your black finish, the final step of the buffing process should be the swirl remover on the foam pad. I think this is the step you'll need. Unless 3M has changed their formulation in the past year or so, most of the body shops around here changed to using Presta products as they had issues with 3M on dark finishes.... looked good until you roll it out in the sun. Once they start to have rework to get something out the door, they look for another product.
I bet if you convert to a pressurized system and figure out an asthetically pleasing way to pull more air through the core, your overheating issues will go away. The pressure on it's own might do the trick if you have enough core area. No paint stores in the area, so I don't think I can readily get Presta products. I have access to some 3M and very limited Meguires. I'll look for it online. What issues are shops having with 3M? Haze? Discolor? Or just not enough cut? I have quite a bit of 3M stuff left over from my sign and motorcycle painting days. FinessIt system and some final glaze. I use a series fo three foam pads, hard with FI1, soft with FI2, and a soft waffle with the glaze. I haven't tried it on the car as the guy who painted it did the buff.
It seemed it didn't do the job. As you described, it would look fine inside under lights, put it outside and it was hazy or cloudy looking. You'd probably have better luck using the older 3M stuff than the newer. Seems the main ingredient of the newer stuff (first on the list, aqua) is water. Ever wonder why so much slings off the pad? Btw, Presta does sell online from their website.
There is a simple and common fix for your water pump location . . . kits are sold regularly on eBay by Chevy Dave. $40 + shipping and a little personal time with the tools and motor and you are on your way to cool cruising! http://cgi.ebay.com/ebaymotors/1955...tZVintageQ5fCarQ5fTruckQ5fPartsQ5fAccessories
Thanks for the link, yes I've seen that kit. But I needed to know if the pump and pulley presently on the truck will work or do I need to get something different?
You buy a new "old" pump for a 216/235 from 1941..1954 - and you put an older harmonic balancer with a smaller pulley on it so as to not overspeed the new pump (which has a much smaller pulley) . . . Typically you take these parts from the original 216/235 that you pulled from the truck - but in this case, your original motor was an Oldsmobile and obviously completely different. So in summary - Adapter Kit New pump from the auto parts store (comes with a pulley on it - pick the pulley width to match your generator) New Harmonic Balancer with a pulley width to match your generator New Belt New Fan
Love six cylinder engines, love G.M.C. trucks, love this beautiful truck that is rare and sweet. Your adjusting and paint cutting is very impressive. Nice to get the low down on some new product, dark paint can be cruel. Thanx for your wonderfully detailed thread, ~sololobo~
Is that script just painted on the tailgate? I have never found a 36-37 with anything but the smooth tailgate. That is as nice of example as I have seen, nice, but he got a little carried away with the black accents IMO.
Thanks for the comments guys! We had planned to remove the front end during the water pump relocation, and given some slight leaks found in the radiator, it only made sense to go with a new one while apart. Although they did not have a direct replacement due to the air deflectors and mounts on the original, props go out to the guys at Walker Radiator. We sent them the old radiator to salvage the rare parts for the new radiator, and they sent a replacement in short order. Their price was just a few dollars cheaper than a recore from a local shop, and they used new tanks....so he should have years of driving ahead. It did take a couple trips to the local Napa store to get radiator hoses that match up to everything, so the owner did get a "treasure map" list of all the new parts that went in. He has been driving it with no further issue with overheating. To my knowledge, that is the original tailgate, with the logo embossed into the metal. I think what you are referring to as Black accents is actually green to match the fenders.
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