Crankcase Ventilation

[NORTH]

I'm pretty well convinced my 65 has a non original engine in it. Thanks for all the info.

I've noticed that there is a lot of smoke coming from the oil fill tube and from under the car from the crankcase vent tube. I have looked in the shop manual for clues to this problem but so far have not seen the answer. Could this engine just be tired and have a lot of blow by? Has anyone else experienced this problem?

 

[2-77s 1-85 2-86 TCs]

Yeah, I believe that means there's excessive blow-by in the engine. In which case, I'd say get another motor or rebuild that one. The way I look at it, you might as well get it overwith if you may need to do it later anyway. Check to make sure I'm right about the blow-by, though. It may be other things, also, that you could check without needing a rebuild, but I'm pretty sure about what I said. By the way, it could be valve seals in the head, or it could be your rings are bad. How long did the car sit before you got it?

Rick

 

[Joe Vandatta]

I think you are getting blow by. The best way to find out is to run a compression test. Low and unequal readings would make it obveious that you have sealing problems. If you have a lot of miles on the engine you had best opt for a rebuild if you are going to keep the car.
Joe

 

[tbird5866]

NORTH: As I recall, 1965 Thunderbird 390's did not have a crankcase vent tube. Does your car have one? It should have a PCV valve in the RH valve cover. No?

 

[t-bird-art]

Ford stopped putting the crankcase venelation tube on the Birds after 1962. 63 and after have PCV (positive crankcase venelation where the intake manifold sucks fumes out of the crankcase back into the engine to burn). The old draft tube simply sucked the fumes out of the crankcase and away into the atmosphere.

 

[t-bird-art]

Worn valve seals mentioned above cause oil to be sucked in the cylinders and black smoke out the tail pipe. Again, compression test done properly will show rings permitting blow by into crankcase and out the draft tube and oil input tube. Don't give up yet. Carbon build up around therings will case harden when an engine sits un-used for years. The rings have to flex as they travel up and down the tapered cylinder walls. Pull the pugs and put 2 oz of transmission fluid in each cylinder. Let sit for a week. After a week turn the engine over with no plugs and blow the excess transmission fluid out the spark pug holes. ( Put towels over the fenders). Re-test the compression. No improveent in readings= rebuild. Some improvement= do another week of soaking. All reading to spec= go to other problems!

 

[Joe Vandatta]

The 66 had a closed system so you must not have the original engine. From what you have said I would replace it with a rebuilt 390 if you are going to keep the car. All 64-66 390's had a closed system.

 

[t-bird-art]

We have all been too quick to rebuild or buy a rebuilt engine in the past- just because "it smoked a lot " and jumped to the conclusion the engine was " tired and worn out". I have driven (2) of the early 60's 390 cu.in. to over 200K and found the rings do not wear out even with that mileage. Yes, blow-by the rings occurs but not because the rings are "tired". It occurs because the ring grooves get so encrusted with carbon, the rings no longer expand and contract traveling up and down the tapered cylinder walls. Cleaning carbon out of the grooves as indicated in my previous reply is the answer as all early T-Bird owners are faced with a $1-$2,000 rebuild . Of course the 390's need front/rear seals + Main and rod bearings if oil and filter changes have been neglected but that is considerably less expense that a complete rebuild. In additon, it is impossible today to find a mechanic who has the training, education or experience or equipment or willingness to do the job right. The bottom line of the above. Make every effort to get your Dream Car that has had proper care and maintenance over the years.

 

[NORTH]

I appreciate all of the input on this issue.
Maybe I wasn't clear on the kind of smoke problem I have.

The car does not smoke out the exhaust, it only smokes out the crank vent tube and out the oil filler cap. It definitley does not have a pvc valve, which indicates it is an early 390.

I have no idea why someone would put an older engine in the car. It has a graet body and interior. I did not pay much for the car, so I'm not real concerned about it. My main issue is does this smoke indicate there is something wrong, or is this normal for an open vent system?

 

[t-bird-art]

Good Grief North. You don't have the picture yet. Crankcase gets smoke from combustion blowing by the rings.Crankcase gasses exit the oil filler tube and crankcase vent tube.

 

[NORTH]

Got it.

I thought you were refering to black smoke out the tailpipe in an earlier reply. Just thought I would make sure we were on the same page.

Thanks for the input. I plan on getting the engine checked out soon.