Engines Locked Up?

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
grumpy?
I purchased a 1968 lemans with what the previous owner swears is a 350 pontiac v8,
the engines locked up and wont turn even with a breaker bar on the crank,
but the previous owner swears it ran when he parked it in the 1990s,
it looks decent, and the cars not in bad overall condition otherwise.
I assumed the engine was in need of repairs and the price was decent, so what now?


well if it was my car Id certainly start by assuming the engine needs a total rebuild as you certainly have no idea as to its true current condition,
It may just be in need of a minor refresh, ie new rings bearings and a timing chain, and new lifters, maybe a new cam. but without careful visual inspection and careful measuring your simply guessing at this point.
Id certainly suggest you verify casting numbers and take lots of accurate measurements

heres a few related threads
read them,
doing so,
should help you avoid a great deal of wasted time and cash


http://garage.grumpysperformance.com/index.php?threads/can-you-unseize-a-seized-engine.5995/

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/page-2#post-88656

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68850

http://garage.grumpysperformance.com/index.php?threads/scat-cranks-related-info.10930/#post-74729

http://garage.grumpysperformance.com/index.php?threads/bearings-and-oil-flow.150/#post-68205

http://garage.grumpysperformance.co...d-what-goes-in-the-dumpster.13135/#post-68515

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.co...g-with-a-local-machine-shop.14419/#post-74389

http://garage.grumpysperformance.com/index.php?threads/engine-removal.15849/#post-95080

http://garage.grumpysperformance.com/index.php?threads/pontiac-cam-and-crank-info.362/#post-2778

http://garage.grumpysperformance.co...on-ring-info-youll-need.509/page-2#post-71538

http://garage.grumpysperformance.co...-you-lose-sight-of-the-goal.15705/#post-94023

http://garage.grumpysperformance.com/index.php?threads/pontiac-performance-tips.451/#post-63761

http://garage.grumpysperformance.co...tech-you-may-not-know.11663/page-3#post-55307

http://garage.grumpysperformance.com/index.php?threads/some-pontiac-related-links.4125/#post-42587
 
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Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
61L2Y%2BilmcL._SX385_BO1,204,203,200_.jpg


purchase of a few related books sure helps

https://www.amazon.com/Rebuild-Pont...03K1NQZE0XC&psc=1&refRID=987Z4QG2W03K1NQZE0XC

https://www.amazon.com/Build-Max-Pe...5VQD4Q226SG&psc=1&refRID=P69RJMX8T5VQD4Q226SG

https://www.amazon.com/How-Build-Pe...X41XZ39PFEZ&psc=1&refRID=PS11RATA6X41XZ39PFEZ
 

johnnmo

Active Member
To free up a engine that has sat and is locked up, try this it works for me.
Leave the engine assembled, connect a source of really hot water to the block--there are several ways. You dont want the radiator involved.
Remove spark plugs and put plenty of light oil in each cylinder. Even trans fluid is ok Marvel mystery oil too.
Now turn on the HOT water source and get the block as hot as you can--well 160 or hotter. Try to rotate it with a breaker bar. If it is still stuck. Cool it off, I drain the hot water and fill it with cold.
Repeat this for several days, or all day if you are really dedicated to it.!! What you are doing is moving the cylinder and rings to loosen them. I have not ever had this fail.
Well, it won't work if it has a rod thru the side!
Works for stuck rings.
 

stepside

Well-Known Member
This side of the pond we are using coca cola or dish washing soap(fairy) to free up rusted piston rings
 
Last edited by a moderator:

T-Test

solid fixture here in the forum
I use to use diesel fuel by filling completely through the top of intake/ carb and let sit for 48 hours. Remove plugs and see if it would turn, if not, let it sit another 48 hours and if not free then, would drain and tear down.
Either way you would have to do a refresh minimum and/or complete rebuild . Make sure block isn't cracked somewhere before you spend any money on the engine.
 
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