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TR6 Adding a PCV valve
- Thread starter steveg
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poolboy
Yoda
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As long as the seal is good the cap isn't supposed to vent. I wouldn't be surprised if it did leak a bit though.
I have but never installed the Good Parts PCV kit. I think I must have bought it for the other engine that was in this car.
https://www.goodparts.com/product/pcv-kit/
This is the sketch RG provided for it's installation.
I have but never installed the Good Parts PCV kit. I think I must have bought it for the other engine that was in this car.
https://www.goodparts.com/product/pcv-kit/
This is the sketch RG provided for it's installation.
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Hello Steve & Poolboy, I really don't like that arrangement in the drawing. What I don't like is that the PCV is plumbed into the vac line to the brake booster. Even though the vac should be drawing everything to the manifold as we all experience oil goes everywhere. I can see over time that the oil would migrate to the brake booster. A brake booster vac line is a clean line its routing being from the intake stream to the booster. This provides the brake booster with maximum vacuum available and there is nothing else there to contaminate it. In providing a connection as in the drawing you are doing two things not normally present in a brake booster line or a PCV system. Firstly you are exposing the booster to possible contamination and secondly you are possibly reducing the amount of vacuum to the booster. That is because the given amount of vacuum available from the engine is now spread out through out the crankcase with its associated leaks. The vacuum will be compromised reducing its ability to operate the booster efficiently.
Of coarse in my mind I don't think it is a worthwhile effort to put a PCV system on a vintage engine. The only reason that a PCV system works on today's cars is because the technology of today compensates for the intrusion of waste gases into the cylinders. Things like variable cam timing, fuel injection and computer controlled engine operation allow such efficiency that the engine can still perform well with waste being dumped into the cylinder. Yes in the '70s engines ran with PCV systems without the new technology. But they did it poorly. We had poor driveability, engine surging and just talk to any professional mechanic to hear the complaints of what they had to go thru to keep the engines running reasonably well. Even to the point of modifying the carburettors and tune specs in defiance of the regulations. These old vintage engines are so inefficient in drawing in the intake charge that any intrusion of waste gases is just going to make things worse. Just note how many drivers of vintage engines will say "my engine runs best when it is a little rich". Of coarse it does. The intake passages are so in efficient that the cylinders need all the fuel they can get. Not more waste gas.
So that leads me to my solution. My solution is based on the premise that any environmental benifit from putting a PCV system on a vintage engine is so negligible that the benefit is inconsequential and a waist of time. There aren't that many vintage engines running around and their use is minimal. So my solution is to do truely what the term means, that is ventilate. Make it like the early engines were, vented to the atmosphere. Either a downpipe or a filter on the end of the crankcase opening. Attached is a picture of my Healey vent for the crankcase. This has the added benefit that the fumes no longer choke up the rear carb which is where the hose originally went. The rear carb is as clean as the front one. That K&N filter doesn't even weep oil and believe it or not my rear main seal doesn't wet the floor. So the answer is Just Vent it, Don't Plumb it.
Of coarse in my mind I don't think it is a worthwhile effort to put a PCV system on a vintage engine. The only reason that a PCV system works on today's cars is because the technology of today compensates for the intrusion of waste gases into the cylinders. Things like variable cam timing, fuel injection and computer controlled engine operation allow such efficiency that the engine can still perform well with waste being dumped into the cylinder. Yes in the '70s engines ran with PCV systems without the new technology. But they did it poorly. We had poor driveability, engine surging and just talk to any professional mechanic to hear the complaints of what they had to go thru to keep the engines running reasonably well. Even to the point of modifying the carburettors and tune specs in defiance of the regulations. These old vintage engines are so inefficient in drawing in the intake charge that any intrusion of waste gases is just going to make things worse. Just note how many drivers of vintage engines will say "my engine runs best when it is a little rich". Of coarse it does. The intake passages are so in efficient that the cylinders need all the fuel they can get. Not more waste gas.
So that leads me to my solution. My solution is based on the premise that any environmental benifit from putting a PCV system on a vintage engine is so negligible that the benefit is inconsequential and a waist of time. There aren't that many vintage engines running around and their use is minimal. So my solution is to do truely what the term means, that is ventilate. Make it like the early engines were, vented to the atmosphere. Either a downpipe or a filter on the end of the crankcase opening. Attached is a picture of my Healey vent for the crankcase. This has the added benefit that the fumes no longer choke up the rear carb which is where the hose originally went. The rear carb is as clean as the front one. That K&N filter doesn't even weep oil and believe it or not my rear main seal doesn't wet the floor. So the answer is Just Vent it, Don't Plumb it.
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OP
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I have the Moss finned valve cover; the cap has a 1/16" vent hole. The stock cap would need a vent.
The Good Parts drawing is functionally the same as this:
EDIT: Vette - with respect, there is much information online detailing the engine-benefits a PCV has in vintage, hotrod, custom setups.
For example:
http://www.hastingsfilter.com/Literature/TSB/94-2R1.pdf
http://mewagner.com/
The Good Parts drawing is functionally the same as this:
EDIT: Vette - with respect, there is much information online detailing the engine-benefits a PCV has in vintage, hotrod, custom setups.
For example:
http://www.hastingsfilter.com/Literature/TSB/94-2R1.pdf
http://mewagner.com/
carpecursusII
Jedi Trainee
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You do not want a vented cap to be used with a PCV system, it will draw a ton of air and over lean the mixture, not to mention burn excessive oil.