Oil breather cap and Draft tube questions

Hey guys, I am fairly sure the 144 in my falcon is starting to get tired, its runs well and has decent performace but has a slight gudgeon pin knock. It does not blow any smoke from the exhaust or use any oil, however after a long run there is smoke coming from the oil breather cap, but not out of the draft tube. Is this normal on these engines with a little blow-by or could my draft tube be blocked?

You'll always get some mist out of the breather on a draft tube engine. If its a pretty steady but light stream all is well, if one cylinder has a broken ring/s you will see a choofing effect from the breather and the ammount will be pretty large.
The draft tube can get blocked but this is easy to test. If at idle and blowby is at an acceptable level and the engine is just expelling hot light gasses you will get, as i said, some light mist from the breather and not much if any from the draft tube, as the engine makes more blow by gasses you start to get more mist from the breather and some from the draft tube also. The gases are hot and will naturally rise to the breather, if there is too much gas it will come from the draft tube too.

Now, to check if the draft tube is blocked, real easy, drive till you normally would see gasses from the breather at idle, now just block the breather and see if the gasses now come out of the draft tube, if yes then all is well, if no then the draft tube is blocked. It is easy to remove and clean. You can also clean out the draft tube fitting cavity in the block but be carefull not to let the sludge and crust go further into the engine.

Im thinking thats normal. Its warm air and the breather is the high point in the engine so thats where it rises to and escapes unless there is some force acting on it like the car moving creating an air draft around the draft tube which then creates a suction through the engine.

The 61 Vette had a vented breather cap and road draft tube. However, on the high horsepower / high rpm engines they had an issue with oil blowing out of the breather and coating the engine. The factory came out with a bulletin to install non-vented caps on engines if the customer complained about the oil blowing out the breather. So, I guess some discernable blow by is normal for road draft tube engines.
Doug

4Litre_SiX":1svhv0se said:

.... has a slight gudgeon pin knock.

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Gudgeon Pin? Where Ya be, matey?

What they said; it's mighty difficult to get much road draft suction at the draft tube when you are standing in front of the car with the hood (bonnet?) up. I have been in central Montana where the wind blows enough that it would nearly suck the oil out of the crankcase, but most places you actually need to be driving to accomplish much.
Joe

Gudgeon Pin? Where Ya be, matey?

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It's all a question of location. Linguist doing field work in rural England asked a local about a place with the most characteristic dialects.

"Dialects? Thar be no dialects hereabouts. But down the road a bit they have one. Us larfs at they."

Thanks for the replies guys, its much appreciated and makes me feel a bit better! Im from Australia by the way, you guys probably call them wrist pins? Anyways I have done the tests that have been described in this thread and it all appears to be normal. The car is question in a 62 XLFalcon Deluxe. The factory vacuum wipers have been converted to 2 speed electric items. Leaving a perfectly positioned vacuum pipe from the intake manifold that has been blocked off. Im thinking I could fit a PCV valve to the back of the rocker cover and run the hose to this vacuum port? I'd also block off the draft tube at the same time. Has anyone set theirs up like this?

4Litre_SiX":2xhy4ohs said:

Im thinking I could fit a PCV valve to the back of the rocker cover and run the hose to this vacuum port? I'd also block off the draft tube at the same time. Has anyone set theirs up like this?

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Just remember that when you fit a PCV you also allow the engine to draw air thru here. So the carb will lean out, so you must recalibrate the carb to suit.

Can and will do, thanks guys.

Will I get enough enrichment with the mixture screw or will I need the jets changed? The reason I ask is I will be rebuilding the carby soon