G506 Class 525 (G7133) restore

[jeffhuey1n]

Update: while reading David Doyle’s G506 book, I noted that all original G506 engines were painted OD green. My engine is a bright GM orange. Looking over many pages of data on the internet, I found a site that lists certain numbers cast on each type engine. Here’s the site: http://1954advance-design.com/Stovebolt-engine/casting-numbers.html. In short, what I have is a 235 cid motor which was used on 1954 trucks. The block was also used on trucks and cars in 1955. That explains the shiny orange paint job. This adds to the difficulty of how far to refurb the truck. I just don’t have enough parts to make it 100% at this time. So, make it work is probably what I’ll do. It’s still going to be a fire truck, regardless.

 

[jeffhuey1n]

The engine code, which took a bit of cleaning to find, says it was built at Flint Michigan in 1954 and was a 235 cid, 115 HP, regular engine. Furthermore, it was built as a truck engine based on part numbers cast in to various places around the engine. Today’s tasks were to remove the fresh air vent, remove the rest of the firewall parts, remove the sound proofing and finisf getting the cab wiring out of the way. Got it all done and also removed the starter. I’m amazed by the excellent condition of everything. The hoses must be original, they broke like hard plastic when I removed them. I’ve started the cleanup of the engine and the engine compartment. That will take a bit of elbow grease to get it all cleaned up properly. So far, only minor repairs needed on the firewall. Just some rounded out holes and lots of dirt, oily dirt and greasy dirt.

 

[jeffhuey1n]

Updated info: after much searching and head scratching, I’ve figured out the probable Registration number. There’s a truck in Doyle’s book “Chevrolet G506” that has an excellent photo spread with all pertinent info. It was delivered in November 1943. That puts it in the same fiscal year (FY) as my truck. The FY started on 1 Aug 1943 with truck number 1001. Using its data I extrapolated the missing number using some algebra. And my truck’s number is 33020xxx. I can now put the correct information on the hood and proceed with repairs. Once it warms up a bit...

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Just when I thought I had it figured out... all fire trucks of that era, especially late war, start with “50”. I think I’ve narrowed it down based on another truck with similar registration numbers. Shucks, I doubt anyone will get to excited about it if I’m off by a digit or two. Figuring out this stuff is half the fun of owning old green trucks.

 

[jeffhuey1n]

Cleanup has begun. My goal is a 100% cleanup +/- a percentage point or two of all crusted on dirt/grease/unwanted paint. With most stuff out of the way, I started cleanup on the engine. I’m using Dawn liquid in water as the cleaner. I’ve got a industrial electrical tooth brush that works okay. Also using small sponge paint applicators, a wood handled steel brush and a spray bottle to do the rinse down. I chose Dawn because it lacks the nasty chemical stench and hazardous health effects. Here’s day one’s efforts:

 

[m1010plowboy]

If they can use Dawn on a DUK then you can surely use it on a CCKW. The different flavors smell great too. Mediterranean Lavender dish soap is sitting on the shelf but don't tell the boys. Simple Green is still a favorite of ours too. That beast cleaned up great so whatever you're doing works.

We can sure see where the 50's GMC 302 inline 6 cylinder engine gets its roots. The block design is real similar and just so simple looking. I wanted to get the M135 on the road so I washed the engine like you're doing, replaced the valve cover gasket and drove it. I did a light re-torque on all the pans and it mostly stopped seeping.

How far are you taking the engine?

 

[jeffhuey1n]

If they can use Dawn on a DUK then you can surely use it on a CCKW. The different flavors smell great too. Mediterranean Lavender dish soap is sitting on the shelf but don't tell the boys. Simple Green is still a favorite of ours too. That beast cleaned up great so whatever you're doing works.
We can sure see where the 50's GMC 302 inline 6 cylinder engine gets its roots. The block design is real similar and just so simple looking. I wanted to get the M135 on the road so I washed the engine like you're doing, replaced the valve cover gasket and drove it. I did a light re-torque on all the pans and it mostly stopped seeping.
How far are you taking the engine?

. I want to completly clean the entire engine. Also, I’m going to remove, clean and repaint parts such as the engine block filter bowl, the air filter, the fan, pulleys and generator. It won’t look brand new but it’ll definitely look much better should I want to show the truck. On a side note: the replacement engine is rated at 115 horsepower. The original was rated at 83 HP. I can see why they wanted to upgrade.

 

[nattieleather]

There can be many reason the engine was replaced. More power being one of them. I would just paint the engine OD like the original should have been and not worry about it. Nobody is going to look at it and say "hey that's the wrong engine." Painting what's in there that works is easier than trying to find and original that may or may not work.

 

[jeffhuey1n]

There can be many reason the engine was replaced. More power being one of them. I would just paint the engine OD like the original should have been and not worry about it. Nobody is going to look at it and say "hey that's the wrong engine." Painting what's in there that works is easier than trying to find and original that may or may not work.

. It may sound a bit strange but I kinda like the look of the bright orange paint. Also, since a 1954 model engine, the 115 horse engine is a all around good thing. I’m going to keep the repaint of the engine in the someday file. If I ever get too bored, I could always tear the engine down and do everything up to snuff. Thank you for the suggestion and ideas! Greatly appreciated!

 

[jeffhuey1n]

Day two of engine cleaning. For today, I continued cleaning the engine and engine bay. I pulled the pulleys, fan and generator with mount. I used my handy dandy sand blasting booth to clean up the fan and pulleys from the water pump, generator and crank shaft. I hadn’t looked too hard at the generator ‘cause it was working but now I find out there’s blades missing from the generator cooling fan. Not sure where to find one of them, yet. I continued cleaning the accumulation of dirt mixed with oil from the engine. Got most of the stuff off the front. Still have to clean the left (drivers) side and the under side of the oil pan. This task reminds me of cleaning out the Main Gear Box bay on the CH-53. If only I could still use the liquid freon... dump it on the mess and the mess went away. Ah, the good old polluting days when nobody paid attention to how we were doing the mission, just get the job done ASAP. Pics: before and after of the front of the engine, the cleaned up parts and the next challenge, the left side.

 

[hndrsonj]

I'd call John Bizal at Midwest Military and see if he has a fan for the generator....

 

[jeffhuey1n]

I'd call John Bizal at Midwest Military and see if he has a fan for the generator....

. Will do, thanks!

 

[50BMG]

Hey ,I'm not going to use my original motor,I had a 292 built,so if you need any parts contact me.I'm doing a full frame up hot rod resto.

 

[jeffhuey1n]

Hey ,I'm not going to use my original motor,I had a 292 built,so if you need any parts contact me.I'm doing a full frame up hot rod resto.

. The only thing so far is the generator fan. Non engine would be the tow hook on the front bumper. Would you happen to have them?

 

[50BMG]

The only thing on the motor non stock is they put an alternator on it.As far as the front tow hooks mine are cut almost in half,so I'm looking also.I have the complete motor Trans and all levers and acc.

 

[jeffhuey1n]

It

The only thing on the motor non stock is they put an alternator on it.As far as the front tow hooks mine are cut almost in half,so I'm looking also.I have the complete motor Trans and all levers and acc.

. My engine/transmission are complete except for the broken fan. There was a set of tow hooks on eBay. I don’t like the price, maybe it’ll work for you.

 

[jeffhuey1n]

Not much done today. Got the water pump off ‘cause it was leaking around the gasket. lol and behold! It’s the wrong pump! Not sure what the small aperture is but it probably needs to get flow through it to work right. One photo is the current pump, the second is the engine block and the third is what’s supposed to be installed. I hope they have military discount.

 

[jeffhuey1n]

It’s officially day three of engine cleaning. Got a bunch of crud off the head, valve cover, around the thermostat housing and started on the drivers side. I checked out prices for renting a steam machine and they’re a bit expensive. So, tooth brush, scrubby pad, Dawn detergent steel brush (several sizes) and elbow grease. Lots of elbow grease! Pics:

 

[jeffhuey1n]

Yesterday I primered the various engine parts previously removed. Since I had to remove the oil filler neck, I went ahead and got all the pieces parts cleaned up. They should be replaceable in the next couple of days. On the outer section of the crankshaft, there’s an adapter attached which allows the engine to drive the big water pump. Since the pump is broken, I’d like to free up the crankshaft so I can try out the hand crank engine startup. Not sure how to get the adapter off. I drove out the:: I’ll try a couple of things and if unsuccessful, I’ll put out a call for assistance. Pics:

 

[jeffhuey1n]

Got the shear pan reinstalled in the crank shaft. It wouldn’t go back in due to the ends being mushroomed. A little work with the grinder and poof, problem solved. This is the 4th(?) day of cleaning the engine. It’s 90% better than it was. I’ll be branching out to the entire front end, get it cleaned and ready to repaint. Since a steam cleaner as well as chemical engine cleaners were not doable, the Dawn dishwashing soap did great. There was an issue with this, however. Getting rid of soap residue. Since I’m working inside, pressure washer is out. I dug around and found as squirt bottle that worked. Not very well but it worked. My hand started hurting so I looked around for another idea. Then I saw it. I found it on the side of the road some time ago. It works but I had no real use for it. It’s a Nerf Super Soaker and it puts out some serious water compared to the piddly little squirt bottle. Pics: I’ve also started painting the engine peripherals.

 

[jeffhuey1n]

I started sanding the cab and the frame forward of the cab. Lots of little spaces to get into. Tedious is what it looks like. There was at least 4 coats of white paint that’s coming off before I get to the GI green. Pic: