Crankcase ventilation Rover 3.9L V8 w/ Edelbrock carb

[donfaber]

In a nutshell (I'm 66 and still learning) - for my rover V8 with Edelbrock carb.... PVC valve from one valve cover to base of Carb, vent line from other valve cover to air filter inlet on carb.

[donfaber]

Is the setup I've described "correct?"

[DiDueColpi]

Absolutely Don. It's the classic way to ventilate the engine. And it will work just fine. You will have to play around with PCV sizes to fine tune it, mostly to stabilize the idle.
The more modern set up is to use a constant depression regulator to provide a regulated pressure drop inside the engine. This is a little more complex to achieve but it virtually eliminates oil leaks. That's the downside as you no longer know if your British car has oil in it.
Live like you mean it.
Fred

[donfaber]

 -- moved topic --

[donfaber]

Thanks, Fred!

[BlownMGB-V8]

Use the largest practical hose you can for the vent line. 3/4 is good and 1" isn't too big. 5/8" would be OK if these engines didn't have a reputation for blowby. Be sure there is a flame trap in that line.

Jim

[MGBV8]

"The more modern set up is to use a constant depression regulator to provide a regulated pressure drop inside the engine. This is a little more complex to achieve but it virtually eliminates oil leaks. "

Would love to hear more about this, Fred.  As Jim mentioned, these engines tend to be heavy breathers.

[donfaber]

Jim - I assume that's not the same as a breather - can you recommend a flame trap or supplier? Thanks

[DiDueColpi]

Virtually all newer vehicles use some form of this breather system Carl.
It's essentially a large pressure regulator connected between the crankcase and the intake plenum.
It maintains a constant pressure drop differential in the crankcase of around 2 psi. No other vents or breathers are used.
It works very well. We see engines with several hundred thousand miles on them that are perfectly dry.
A good example is the Jag/Rover part AJ87773 to give you an idea.

[ex-tyke]

Here ya go, Carl!

[MGBV8]

I need one!

[donfaber]

Let me know where u find it, Carl!

[BlownMGB-V8]

Is that any different from the big metal one used on the TR4? So no fresh air inlet with those huh?

Jim

[ex-tyke]

Seems to be used on 2000 - 2009 vintage Jags.
Could spend $50+ for a new one, try the wrecking yards or steal one off Kelly's XK8  .

[DiDueColpi]

Nope no fresh air Jim just a light vacuum. The Oringed part goes to the valve cover and the barbed fitting goes straight into the intake manifold plenum. A silicone diaphram and spring regulate the pressure in the crankcase.
Try undoing the oil filler cap while the engine is running Graham. You'll see what I'm talking about.

[BlownMGB-V8]

So... is that any different from the big metal one used on the 1966 TR4?

Jim

[MGBV8]

Sounds like an oversize PCV.

[donfaber]

Found #379-580 - for 70-71 TR6 - Moss Motors

[ex-tyke]

A GM version of the crankcase regulator valve # 25097699

[MGBV8]

"Found #379-580 - for 70-71 TR6 - Moss Motors"

Moss says that is a just flame trap, Don.

[BlownMGB-V8]

https://rimmerbros.com/Item--i-GRID200273

[donfaber]

Carl - I'm only installing a flame trap on left side - pcv already installed on right side. Seems to be the consensus?

Don

[MGBV8]

Right.  I got hung up on Fred's suggestion  of a crankcase depression regulator & forgot that you were only looking for a flame trap.  

I am intrigued by this CDR.  Not sure I really understand the difference between it & a PCV.  I have read that a CDR is a essentially a PCV for diesel engines. It functions in the opposite manner in regards to vacuum.

[BlownMGB-V8]

Part of a stainless steel pot scrubber pad makes a pretty good flame trap. You can use it in any suitable enclosure. As an example, I have about half of a pad strung out and drawn into 1" diameter length of silicon hose which runs from my  mechanical fuel pump block off plate up to the inlet of my Enderlie style intake scoop. You can probably see it in my avatar, the hose is blue which contrasts with literally everything else on the car. Rover uses a canister on the valve cover similarly filled.

I'd like to see an explanation of that regulator compared to the TR4 pcv. Is there a difference in the way they work?

Jim

[ex-tyke]

I'd like to see an explanation of that regulator compared to the TR4 pcv

Looks similar to the PCV that was used in ''65 - '67 MGB's , Spitfires and who knows what else  - I know my '64 never had one.
(photo courtesy of Moss)