Blown head gasket

[Guest chaser1602]

50 desoto flat 6. do flat heads blow head gaskets like more modern v 8 engines. Does water run through the head also. Got steam from the tailpipe

[Guest Silverghost]

Yes flatheads also blow head gaskets.

Water does indeed circulate through most flat cylinder heads.

Some flatheads are more prone to head gasket problems than others !

It seems that the longer 6 s and straight 8 s are more prone to this problem .

Get a quality copper-clad head gasket and use a good gasket sealer like Permatex Copper Coat on both sides of the gasket.

Be sure to properly re-torque the head in the proper sequence to the proper torque spec.

After several hundred miles

Re-torque head bolts again.

Make sure the cylinder head is not warped !

If it is warped a good machine shop can true it up !

Good Luck~

I hope your head is not cracked or rusted through !

[Guest chaser1602]

Thanks for the info and I hope no cracks also

[Steve_Mack_CT]

Chaser, search this topic in the Packard section. 34 Packard Roadsta gave me a great suggestion that helped a lot - use a set of carpenter's clamps to grab the head - they have the grip and will make handling the removal and reinstallation a lot easier. On the straight flatheads the faillure is usually at the back of the block further from the coolant source. Not too bad of a job, and generally not the end of the world either.

Follow Brad's suggestions especially about "chasing" the gasket down after a few hundred miles. My machinist, also a Packard restorer told me they compress a lot and many times hobbyists think they are done once the head is reinstalled.

Remember to drain the coolant or you will get a mess and change the oil once the job is done. I would take the head to a machine shop - they checked mine over for next to nothing.

Good luck with it!

Edited October 22, 2010 by Steve_Mack_CT (see edit history)

[Owen_Dyneto]

You might want to browse the general headgasket replacement advice given for a Packard eight at:

PackardClub.org • View topic - 359 Head Gasket

[Guest Fitz]

When I rebuilt a flat head engine, like other, I retorque after the first warn up and after some hundred miles, but at first , I torque to 15/20 pounds for one day, let it rest. It give the block and head a chance to match together and reducing stress.

It work great for me.

Fitz.

[Guest De Soto Frank]

Flathead MoPars do not necessarily blow head gaskets anymore than any other make / engine design.

If they do, it's usually because the engine was run in an overheated condition and the head warped.

I've been driving unrestored 1940's MoPars for the last 25 years (nearly 100,000 miles between them), many of them high-mileage, and none have blown a head gasket.

First thing to do is check the compression with the engine warm. All cylinders should be within 10#s of each other. Two cylinders next to each other with low compression suggests a gasket failure between them.

"Steam" from the exhaust is not always an indication of a coolant leak. A cold engine / exhaust system will produce a cloud of water vapor out the tail-pipe, particularly in cool weather; this should go away after the engine reaches operating temperature (160-180 deg F) and stays there for 5-10 minutes. If you continue to get clouds of white vapor that evaporates quickly(smoke from burning oil has a bluish tinge, and hangs in the air longer), then start looking for a coolant leak. If you're running anti-freeze solution, the white smoke will have a "sweet" smell to it.

If it does look like a coolant leak, another test is with the engine cold, remove the fan belt ( to disable the water pump ), remove the radiator cap and add coolant as necessary to bring the level above the tubes / baffle, then start the engine.

Have a helper goose the throttle a couple of times while you look into the radiator filler; a stream / collection of air-bubbles after each "goose" suggests combustion pressure escaping into the cooling system. (Note: leaving the fan-belt on/water pump active will induce circulation which will render the test ineffective.)