Trans-Am tribute crankcase ventilation

[masergt]

So I posted a thread on the main page on this 1968 Tran-Am tribute.

1968 Trans-Am Tribute

I am curious about the crankcase ventilation set up plumbed from both valve covers to a cannister (I presume it's crankcase ventilation and not part of a dry sump set up?). Can someone explain it's function and, assuming it's ventilation, does this provide some enhanced function?

[gotstang]

Oil vapor collection in place of a PCV system, so that the car doesn't smoke during extended high RPM use....at least that's my guess.

[amorrow02]

Right, just looks like a fancy catch can for the crankcase vapors. I've also seen longer breather tubes added to stamped steel valve covers that extend upward on '65-8 roadracers, as well as nifty setups like on the later '69-70 T/A cars that have tubing connecting both banks with two inline breather caps.

[roadracer]

The catch tank is a modern day requirement required by most sanctioning bodies and was not run in the day.

There is no performance advantage, in fact,..it adds weight (= bad).

[JonK]

Originally Posted by amorrow02

I've also seen longer breather tubes added to stamped steel valve covers that extend upward on '65-8 roadracers

Does anyone still sell these? I'd like to find a pair of stamped steel with the long fill tubes that have a ~45* angle to them like I've seen on some roadracer/transam mustangs.
Jon

[gotstang]

Originally Posted by JonK

Does anyone still sell these? I'd like to find a pair of stamped steel with the long fill tubes that have a ~45* angle to them like I've seen on some roadracer/transam mustangs.
Jon

Cobra Auto or Shelby Parts or someone makes them, but they charge through the (insert expletive here) nose, something like $500. If you could come up with all the bits, I bet you could get a set welded together on the cheap. (Hint: I own a welder )

[amorrow02]

Yea, just get some steel tube sized for standard push-on breather caps, and some plate steel for the gusset reinforcements, and weld away. Someone could probably bend them for you easily, or just get the tubing from a shop capable of pre-bending what you need.

I just picked up a couple pairs [new to welding, so I'm sure I'm gonna screw up] of '70 351C valve covers to replicate the '69-70 setup for my '70.

[henry_v]

Crankcase oil vapor ingested via the PCV system decreases horsepower.

[jeff33702]

Originally Posted by henry_v

Crankcase oil vapor ingested via the PCV system decreases horsepower.

..and causes detonation which would be a real risk with these iron-headed high-compression motors.

[couper69]

The catch can is required by most all Vintage Road Race organizations and SCCA . It's primary function is to collect any oil due to blow by or from an engine failure - The whole point is to keep oil off the race track.