254 Engine Troubles/Questions

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sammywayne23
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254 Engine Troubles/Questions

Post #1 by sammywayne23 » Thu Aug 30, 2018 5:26 pm

Hi guys,
I am new here and also new to these engines but have been reading over the threads the past few days so bear with me. Great info and a wealth of knowledge here. So a few years ago I purchased an F6 with a 254 (PO says it was rebuilt in the 90s) and between work and school I got it running this past May. The first two starts I had the engine running without the coolant system hooked up, ran well for running for first time just for maybe 15-20 seconds. I then hooked up my hoses and hooked up my radiator, filled with coolant. Well coolant wasn't circulating so I checked thermostat and it was bad and replaced it.

This fall I am combing over the engine (dropping pan, new head gasket, etc) and I would like to check for cracks when I have the engine on a stand. I pulled this valve covers this week and there wasn't any sludge in there, really clean springs looked like they were painted yesterday. I would like to go through my coolant system to check for leaks as it had white smoke from the exhaust when last running. Is there a good way to check for coolant leaks in the block? Want to be sure before I proceed and when I drained the oil the viscosity was much lower, I couldn't tell if I had coolant in oil or it was the additive I put in for my rear seal. Also where do these engines usually have cracks at typically?

If I wasn't in college right now Id love to do a full rebuild but I don't think I have the funds, maybe in a few years.

Sam

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bubba22349
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Re: 254 Engine Troubles/Questions

Post #2 by bubba22349 » Sat Sep 01, 2018 10:54 am

One area they can crack is from the exhaust valve seat to the intake seat or into the water jacket. These can be repaired using the pinning process. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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B RON CO
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Re: 254 Engine Troubles/Questions

Post #3 by B RON CO » Sat Sep 01, 2018 8:19 pm

Hi, maybe there is no reason to just take it apart. You can re torque the head bolts after some heat cycles.
I would run it and watch it to make sure it doesn't overheat.
You should run it at @ 2000 RPM, rolling the throttle to break it in.
I would put my hand over the radiator to check for cold spots. Cold spots show blockage which could lead to overheating.
If you drained the oil hot it will be thinner. If water was getting into the crank case, there would probably be a milky look to the oil and around the oil filler cap.
To check for cooling system leaks we use a pressure tester. I wouldn't go over 10 lbs. pressure.
A compression test will also give you good information about your engine.
Good luck
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
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