The Stovebolt Site Forums The Parking Lot Big Bolts Hello to all, ... let the adventure begin

Brand new to this forum, A week ago I, much to my wife's chagrin, I won a 1953 GMC 353-24 off Ebay I know it is kinda like buying the proverbial "pig in a poke" but I always wanted a big truck, it was close to home, and the price seemed right. It is a 161 wheelbase with a flat dumpbed and two speed axle. Admittly it is not not much in the beauty department,niether am I but that is a whole nother story . It has a 248 that is stuck at the moment, does anyone have any links to freeing a stuck motor? If the motor is unfixable, is anything really unfixable :rolleyes: are there any links to motor swaps on the big trucks? Thanks

Do a search of his site theere have been several threads on stuck motors. Had good luck wih diesel fuel?marvel mystery oil mixture poured it in he cylinders and let it set a few days. was able to bump it over with starter. make sure no one is standing near motor as fluid may be shot out spark plug holes. (found out by experence) Try the engine and driveline fourm in this site also. Welcome to the stovebolt page.

Yep, I second that. I think the Marvel is a little bit better than the diesel. You might also try the use of a breaker bar, cheater and socket on the end of the crank....with the disclaimer that I am new to big trucks also but it has always done the trick on the smaller vehicles (if it could be done) and I presume just about everything has a nut on the end of the crank. Just make sure you are tightening when you try to break it free or you will be momentarily happy for nuthin....and if you use a big cheater, don't push too hard...just persuade. Dont want to strip or break somethin down there.

Don't know about links, but if you pull all the plugs and fill the holes with diesel, and refill 'em daily for a week, then you can try to turn the crank manually with a big wrench on the cranknut. If it won't turn, do it for another week, then another. If the engine won't turn after 3 weeks, it ain't likely to without a major. The main thing is to give it time, and don't try too hard or something (probably a ring) will break. The more easily it frees up, the better your chance is of having a tight, trouble-free engine which doesn't use oil. So don't pull too hard. And, like KB3 says, stand clear of the plug holes when you pull.

-Mark

Great minds think alike . . fools never differ. I still like diesel.

I would use a penetrant like WD40 and the like. Let it set for a few days, rock the truck back and forth in gear until it's loose. Pull the valve cover and douse the valvetrain with it too.

Good luck and welcome to the Stovebolt,
Scott

I really like PB Blaster. And I think I just saw some in a gallon can at Lows. It is usually available in a spray can at good auto parts stores.
Grigg

I also have have good luck with PB Blaster. I pull the plugs and put about 3 or 4 ozs in the hole with a funnel. Ussally takes a couple days and they come loose. After its loose drain the oil, as thats were most of the blaster goes, and you dont want to pump it though the motor.

I'll now show my ignorance of ealy GMC's because when I read that you had a "1953 GMC 353" I started thinking "oh, 3-53 Jimmy diesel". But alas....it's a lil' ol' 248.

Good luck on unsticking it.

welcome to the big bolts,I have a 53'4400 and it had a 216 in it,it turns but I haven't messed with it yet.

Moneypit;
And Obsa, come to think of it;
a 3 or 4-53 detroit might be the hot ticket for that old truck. I know they were putting 'em in buses, so it'd probably be a correct application, and you'd have more power AND better economy.

I am not up on the gmc model numbers, but some of the Advanced Design medium sized and larger trucks came factory with 3-71, 4-71, and 6-71 Detroit diesels.

A 3-53 even with a turbo is not worth the trouble to swap into a truck. Not quite enough power.

However, A 4-53 with turbo is a nice swap in my oppinion.
I am just finishing the tough part of swapping a 4-53T in my 48 Chevy 2 ton.
Search this site for Detroit Diesel if you are interested.
And I welcome any questions on the subject, just start a new thread or send me a PM.
Grigg

Years ago I had a non-turbo 4-53 in an old MCI Courier (ex-Trailways bus) which I converted to a motorhome. It was sedate, to be sure, but on the highway it got 9+ mpg and would cruise at 55 very nicely indeed. Its curb weight with full tanks was a hair under 30,000#. The Detroitmeister told me I could enhance power output by simply changing to bigger injectors, but there was just enough as it was.

in line with 48bigtrucks suggestion someone in past suggested tapping valves with hammer to make sure they aren't stuck. I didn't on my 54 and bent a push rod.

The 248 in my truck appears to need major work. while checking with vendors on the net it appears that repair parts are close if not nonexistant. Now am wondering about engine swaps. I want to stay with a inline motor it appears that a 235 might be the easy way out. But also a later 250-292 might better in the long run. Any thoughts?

Somewhere else on this site I've read that a 292 is more of a challenge to swap because the block is different, but the 250 is a 235 on steroids. that I DO know.

I think the only difference on a 292 is the offset motor mounts. and the exhaust dump might be different. but i have been proved wrong before.

obsa, welcome to the madness. Good luck with your truck!
hotshoe36, I'm not sure what you mean by the 250 is a 235 on steroids. They are very different motors inside and out and mount in the truck entirely differently. Very few parts interchange.