1955 ford with a 302 engine/oil question
 

Hello everyone,hope all of you had a great Thanksgiving Day. This morning I decided to do an oil change on this 302.As I drained the oil,I noticed that the oil was a milky color instead of just plain dirty oil.The engine is not overheating at all but could it still be a blown head gasket causing this milky looking oil? Need some suggestions on this problem. Thanks.

Re: 1955 ford with a 302 engine/oil question
 

winter is coming on.when you have an old engine or to much stop and go this happens.blow by when an engine is cold causes this.

Re: 1955 ford with a 302 engine/oil question
 

Check the PCV system or road draft tube for proper operation. The fill cap screen/mesh should be clean also. Finally, make sure the thermostat is operating properly and engine is coming up to operating temperature. Blown head gasket will typically exhibit white exhaust.

Re: 1955 ford with a 302 engine/oil question
 

Try a cooling system pressure test to be sure, it needs to hold. Worked on a car once the customer kept bring back in with antifreeze all over under the hood. Pressure tester said it held good. Older mechanic came and looked at it, put pressure tester on, pumped it up and the said start it and rev it up. Around 4000 rpm we had antifreeze flying everywhere coming from head gasket. Head bolt had stretched and was ready to snap between first thread and shank. Besides head gasket on a 302 coolant runs through intake manifold and timing cover. Try a pressure tester.

Re: 1955 ford with a 302 engine/oil question
 

Thanks guys. I will check all the things mentioned here. Will let you know what I find out on the problem.

Re: 1955 ford with a 302 engine/oil question
 

Are you losing water and gaining oil? Is so then you have a leak. No white smoke out the tailpipe, then probably not a bad head gasket. Maybe not running the car long enough

Re: 1955 ford with a 302 engine/oil question
 

Well,I did a coolant pressure test and it held good and no leaks at all. I also did a combustion leak test and the fluid did not change from blue to yellow so it looks like the head gaskets are ok.Temperature is okay at 180 degrees after idling for 20 to 30 minutes.I also did a compression test and all cylinders are between 145 and 150 lbs.
I am going to drive it around town Monday for at least an hour and see how it runs.
If no problems are seen,it should be ok now. I think that the problem is not running it enough to get everything back to normal. Thanks for your help and suggestions.

Re: 1955 ford with a 302 engine/oil question
 

it doesnt hurt anything some old fords i drove had the dipstick froze in in the morning.they went for years.

Re: 1955 ford with a 302 engine/oil question
 

Depending on the temperature and humidity where the car is parked/stored, and like the outside of a glass of your favorite icy cold beverage... the inside of a cold engine can condense moisture which drips to the low points, same as the oil.
Infrequent short trips don't get the oil & engine hot enough to evaporate the water out. Your idea of an hour long drive should be a good one.
.

Re: 1955 ford with a 302 engine/oil question
 

Winter of 69 I was out of school for Christmas break. Cold and damp in Seattle as usual. I drove short distances for a week, probably never 5 miles and not above 40mph. I went out and pulled a valve cover to set the valves and it was full of dirty yellow foam. When I wiped it out it was obviously mostly water. I freaked out, but my Dad came home and said “go drive it about 30 miles on the freeway”. Sure enough 20 minutes across town and a 30 mile dash at 70 (no traffic in those days) when the car cooled off it was clean as usual. I wouldn’t believe it if I hadn’t seen it.

Re: 1955 ford with a 302 engine/oil question
 

Is the PVC SYSTEM functional on the engine? Do you know about what year the 302 is?

Re: 1955 ford with a 302 engine/oil question
 

Thanks to all for your help. The pcv is working ok.I have a new pcv valve and I have full vacuum on it.With the engine running,I put my finger at the end of the valve and It has good suction. I will find out tomorrow how well it runs when I go for the 1 hour run.

Re: 1955 ford with a 302 engine/oil question
 

OK...

Not trying to correct you or anything of that ilk ...

The best way to determine PCV SYSTEM operation/integrity (IMO) is to put a vacuum gauge on your dipstick tube and see if there is any vacuum (with engine running - beat you to it oldmics :p ).

The air intake may be blocked, the engine has a large oil leak(s) drawing outside air, etc.

Please, no food fights. I just got my laundry bill from the last go-around ... :rolleyes:

Re: 1955 ford with a 302 engine/oil question
 

KULTULZ is correct. 302s that have the PCV located in the rear portion of the intake manifold are notorious for "gunking" up and not pulling fumes and moisture out of the crank case. If it is in the valve cover there should be a "cage" with "steal wool" in it. Make sure it is clean as it will clog up over the years especially if you don't heat soak the engine on a regular basis.

Re: 1955 ford with a 302 engine/oil question
 

Ok guys.I took my wagon out for a drive and I drove for about 50 miles and made it back home ok with no problems at all.Engine did not overheat,no white smoke at all eighter. After I got home,I checked the oil and it was back to normal,not milky anymore. It must of been moisture like some of you guys said. It ran really nice.Almost done with it.I had ordered a speedo drive gear and that's what I'm going to replace next to see if I can get the speedometer to work.
Thanks to all for your help.

Re: 1955 ford with a 302 engine/oil question
 

Quick question- how much vacuum should I have from the dipstick? I know it varies with throttle position. Or is it more important to just see any vacuum reading to show it’s pulling?

I will be adding a PCV valve to my Y block and would be a great idea to check the system this way.

Thanks,
Mike


Sent from my iPhone using Tapatalk

Re: 1955 ford with a 302 engine/oil question
 

Measure the amount of vacuum in the crankcase.

https://dannysengineportal.com/wp-co...cuum-guage.jpgvacuum gauge With the engine at normal operating temperature, block off the PCV breather tube or vent to the engine (usually the hose that runs from the air cleaner housing to the valve cover on the engine). Pull out the dipstick and connect a vacuum-pressure gauge to the dipstick tube. A typical PCV system should be pulling about 1 to 3 inches of vacuum in the crankcase at idle. If you see a significantly higher vacuum reading, the intake manifold gasket is probably leaking and pulling vacuum on the crankcase (replace the leaky intake manifold gasket). If you see no vacuum, or find a buildup of pressure in the crankcase, the PCV system is plugged. Or it may not be pulling enough air through the crankcase to get rid of the blowby vapors.
NOTE: If the engine has a leaky oil pan, valve cover or intake manifold gasket leak, or leaky crankshaft seals, it will not be able to develop much vacuum in the crankcase because it is pulling in outside air (which is also unfiltered and can further contaminate the oil).

To find a crankcase air leak, you can lightly pressurize (no more than 1 to 3 psi) the crankcase with shop air via the dipstick tube or oil filler cap or breather after blocking all the other vents. Do not use any more air pressure than this or you may create leaks where there were no leaks before. Then use a spray bottle to squirt soapy water around the gasket seams and seals. If you see bubbles, you have found an air leak (replace the gasket or seal as needed).
A smoke machine also works great for finding crankcase leaks as well as vacuum leaks. A smoke machine generates a smoke-like vapor by heating mineral oil. The mist can then fed into the intake manifold to check for intake manifold vacuum leaks, or into the crankcase to check for internal engine air leaks. Any leaks will allow the smoke to escape and you will see the smoke on the outside of the engine.

SOURCE- https://dannysengineportal.com/pcv-p...ion-valve-faq/

Re: 1955 ford with a 302 engine/oil question
 

@Kultlulz - will that "dipstick check" method work on a y block that has the original oil filler cap? Seems like in the original design that location is where the intake of air to go through the crankcase was placed...

Re: 1955 ford with a 302 engine/oil question
 

Yes, either/both OPEN or CLOSED SYSTEM.

SOURCE - http://www.secondchancegarage.com/public/239.cfm

Re: 1955 ford with a 302 engine/oil question
 

Thanks for the great info on the pcv system Kultulz.I followed the link you put here and read the article.Very informative and educational.Will keep it handy for future use. I am going to double check the pcv in my 55 to make sure its working properly.I noticed where it mentioned that if the pcv system is not working properly,the oil can be contaminated,causing internal problems in the engine.