PCV conversion questions
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Mountain Pass
Joined: Nov 2020
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I just glanced at your smoke thread again. It's normal to have white steam coming out of a road draft tube once the engine is up to temp. You want the engine to run 180 or warmer to drive moisture out of the oil. Moisture is in the blow-by gases. Anytime you burn anything...natural gas, gasoline, firewood, etc..water is a by-product. The PCV system or in your case a road draft tube pulls that moisture out of the crankcase.
As for all that oil on the firewall, you may just have a weird oil leak...though I'd think your mechanic could find that. Sure is a LOT of oil. Oil leaks usually dribble down the engine block and onto the ground or splash back to the tranny and on to the rear differential. What you have looks more like an oil eruption.
As for all that oil on the firewall, you may just have a weird oil leak...though I'd think your mechanic could find that. Sure is a LOT of oil. Oil leaks usually dribble down the engine block and onto the ground or splash back to the tranny and on to the rear differential. What you have looks more like an oil eruption.
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Mountain Pass
Joined: Nov 2020
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Yeah, you can think of a leak down test that way. It should show you if you have leaking intake valves, leaking exhaust valves, leaking rings, or all three leaking. Get the engine to operating temp and make sure your truck is blocked so it won't move when you pressurize a cylinder.
I think "push rod cover" is the valve cover. I'm guessing you'd need a new valve cover if you switched to a PCV system. I don't know. I'm curious what reasons folks gave you that a PCV system is better than a road draft tube. You won't notice any measurable engine performance.
PCV system is only there to keep the oil cleaner by scavenging blow-by gasses. If it gets clogged then you might build up enough crank case pressure to push oil through engine seals and gaskets. But you don't have that, just a road draft tube. And the road draft tube does as good of a job scavenging crankcase blow-by gases as the PCV system.
I think "push rod cover" is the valve cover. I'm guessing you'd need a new valve cover if you switched to a PCV system. I don't know. I'm curious what reasons folks gave you that a PCV system is better than a road draft tube. You won't notice any measurable engine performance.
PCV system is only there to keep the oil cleaner by scavenging blow-by gasses. If it gets clogged then you might build up enough crank case pressure to push oil through engine seals and gaskets. But you don't have that, just a road draft tube. And the road draft tube does as good of a job scavenging crankcase blow-by gases as the PCV system.
Cargo Master
Joined: Jan 2016
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There is some power gain by applying a vacuum to the crankcase to help seal rings tighter but you won't get that on a standard PCV setup.
For venting the crank case, it's at least equally if not more important to get the oil temp up enough to drive out moisture and combustion gases regardless if there is a PCV system or draft tube.
I don't mean to poo-poo your plans though I do think you've been led a little astray. On a modern, emissions controlled car I keep the PCV system and maybe even add a catch can. On one of these classics, there really is no measurable benefit to swap from draft tube to PCV system.
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Mountain Pass
Joined: Nov 2020
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Adding or deleting a PCV system may require recalibrating the air:fuel ratio. However, if you ran your truck with a draft tube and then switched to a PCV system I doubt you could measure any difference so long as your carb was optimized for each scenario. Unless a PCV system is tuned perfectly, it will cause build up of snotty goop on your intake valves and possibly on your piston rings. That won't help mpg.
There is some power gain by applying a vacuum to the crankcase to help seal rings tighter but you won't get that on a standard PCV setup.
For venting the crank case, it's at least equally if not more important to get the oil temp up enough to drive out moisture and combustion gases regardless if there is a PCV system or draft tube.
I don't mean to poo-poo your plans though I do think you've been led a little astray. On a modern, emissions controlled car I keep the PCV system and maybe even add a catch can. On one of these classics, there really is no measurable benefit to swap from draft tube to PCV system.
There is some power gain by applying a vacuum to the crankcase to help seal rings tighter but you won't get that on a standard PCV setup.
For venting the crank case, it's at least equally if not more important to get the oil temp up enough to drive out moisture and combustion gases regardless if there is a PCV system or draft tube.
I don't mean to poo-poo your plans though I do think you've been led a little astray. On a modern, emissions controlled car I keep the PCV system and maybe even add a catch can. On one of these classics, there really is no measurable benefit to swap from draft tube to PCV system.
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