Smokin oil fill tube

thrush544 · Post by **thrush544** » October 24, 2009, 3:10 pm

Ran into town today to pick up a few things. When I got out of the store to go home my 62 stalled a few times at stops and was hard to start. I was less than 10 min in the store so it shouldn't have cooled down. I had to pretty much feather the gas most the way home to keep her running. I am figuring I need to replace or rebuild the carb. Did not smell gas as if the float stuck. Anyway when I got home and opened the hood the oil fill tube was smokin bad checked the oil and it's about half a quart low. What else would cause that, any ideas?
Thanks.

God bless

ABA · Post by **ABA** » October 24, 2009, 3:57 pm

Was the dip stick sticking out of the tube some?

OGNC · Post by **OGNC** » October 24, 2009, 4:04 pm

Blow-by from a cylinder. Either by the rings or even a bad valve stem seal will cause it. My Y-block in my 59 F-100 does the same thing and it has since I have owned it. It is about time to rebuild the powerplant in the old girl...

Obsa · Post by **Obsa** » October 24, 2009, 7:21 pm

Does your truck have a PCV system or is it the old road draft tube ventilation type? If you have the latter it might be clogged with carbon. The old school way of cleaning them is to remove the tube from the engine and build a small fire out in the shop yard and place the draft tube into the fire to burn the carbon out.

ABA · Post by **ABA** » October 24, 2009, 7:57 pm

OGNC wrote:Blow-by from a cylinder. Either by the rings or even a bad valve stem seal will cause it. My Y-block in my 59 F-100 does the same thing and it has since I have owned it. It is about time to rebuild the powerplant in the old girl...

Yeah that's what I was thinkin'...had it so bad in one engine the dip stick would be sticking up 1/2" or more.

Obsa · Post by **Obsa** » October 24, 2009, 8:18 pm

Y blocks have Road draft tubes I know for sure the one in the son's 63 does and it was full of carbon when he got it. The way they work is they hang down behind and below the engine under the truck. The airflow over the end of the open tube creates a low pressure area that draws out the crankcase vapors. A very simple system that works well when the tube is not clogged up.

64 f100 · Post by **64 f100** » October 25, 2009, 12:38 pm

64 had the pcv system and I believe it was the first year for it. The one ton I just bought does not have it, so maybe the bigger trucks lagged behind on this item. The road draft system lets you leave a cloud of smoke behind you and often clogged up, creating a back pressure problem forcing oil out the rear main. Nearly all the old yblocks with any mileage, had this problem. The pcv system really helped this problem out, as the road draft tube did not work all that well. The suction of wind going past the tube did not work all that well especially at low speed, in my opinion.

Rich

Obsa · Post by **Obsa** » October 25, 2009, 2:59 pm

Rich,

You stated "Nearly all the old yblocks with any mileage, had this problem. The pcv system really helped this problem out, as the road draft tube did not work all that well. The suction of wind going past the tube did not work all that well especially at low speed, in my opinion. "

I believe that this is because the road draft tube was a maintenance item that rarely got maintenance. The first mechanic's job I worked at right out of High School was at a somewhat shady old codgers shop who would buy old cars and trucks usually under 100 dollars or less that were heavy smokers the owners mostly thought they needed major engine work and practively were giving them away. Almost to a T the first thing he would do was to pull the RDFs and use the fire trick on them. It did not fix them all but well over half responded to this treatment.

64 f100 · Post by **64 f100** » October 25, 2009, 6:47 pm

I have no doubt that some of the time the cleaning helped, it certainly couldn't have hurt. I think the pcv system does not eliminate any serious problem no more than the road draft tube. The pcv system does have one advantage in putting the fumes back into the engine where these may be burned, instead of just coming out from underneath the car or truck.

Rich

thrush544 · Post by **thrush544** » October 26, 2009, 7:48 am

Thank you for the wealth of information. I will check on her tonight for the tube and see if she's clogged. Seems to have good compression. I don't know if she has hardened valve seats which is a concern. I'll do a compression check as soon as I get my 2001 fixed.

Thanks again for all the help,

God Bless,
Ed