pcv direction or orientation (stumble on idle)
06-20-2014, 05:00 PM
#1
Le Mans Master
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pcv direction or orientation (stumble on idle)
I have it hooked up to the front of the base on a edelbrock carb. Also, the front breather sometimes backfiring off slightly whenever I drive.
What direction is the pcv RPO 242 suppose to go?
For some reason I cannot get the engine to idle correctly. Lots of surging and bucking when I drive it.
I have tried to adjust the carb mixture screws, timing advance and changed the springs on the distributor. I have the vacuum hooked up on the right front side (passenger side) on the carb port.
Anyways, I thought I would ask you all first before I do anything else. How should I check for any vacuum leaks? Can I use carb cleaner and spray it down?
What direction is the pcv RPO 242 suppose to go?
For some reason I cannot get the engine to idle correctly. Lots of surging and bucking when I drive it.
I have tried to adjust the carb mixture screws, timing advance and changed the springs on the distributor. I have the vacuum hooked up on the right front side (passenger side) on the carb port.
Anyways, I thought I would ask you all first before I do anything else. How should I check for any vacuum leaks? Can I use carb cleaner and spray it down?
Last edited by jimh_1962; 06-20-2014 at 05:05 PM.
06-20-2014, 05:14 PM
#2
Le Mans Master
Jim - Not sure if this is going to help you or not but here's a pic of the Edelbrock #1406 on my 300 327 in the 65 Coupe. PCV line is connected to the front baseplate orifice and the vacuum line is connected to the (slightly) lower of the two front vacuum take-offs, the one on the driver side.
Mike T.
Mike T.
06-20-2014, 05:24 PM
#3
Le Mans Master
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that helps! I have it hooked up the other side so maybe that's part of the problem.
I still cannot figure out the stumbling. I am running a petronix ignitor II.
I still cannot figure out the stumbling. I am running a petronix ignitor II.
06-20-2014, 05:42 PM
#4
Le Mans Master
I meant to add that the PCV could be hooked up to either front or backside pipe connection since they both connect to the baseplate passages. On your 62, if you are running a true PCV, is your incoming replenishment air coming from the air cleaner down to the rear draft tube hole in the block? As to the stumbling, what sort of vacuum reading are you seeing?
Mike T.
Mike T.
06-20-2014, 05:47 PM
#5
Le Mans Master
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Yes, true PCV. It is connected to the back of the block with the breather underneath the intake. The needle slightly bounces around 11 HG. Very slightly. The tach does the same thing. Under load it was popping.
06-20-2014, 06:42 PM
#8
Team Owner
RPO-242 is very straight forward and an 'open' PCV system. The road draft tube hole has an adapter on it (or a rubber grommet) and a rubber hose leading to the PCV valve which is attached to the carb at FULL manifold vacuum (e.g. taken off BELOW the throttle plates at the base of the carb). The setup requires a VENTED oil filler cap or it won't work. Selection of the PCV valve is critical. The original CV-590s are what some use. The air cleaner is uninvolved in an 'open' system like the RPO-242.
I went with the Standard SIV-100 (or Fram-FV100 or NAPA 2-9255)...you don't want the normal vacuum affected more than a factor of 2; actually the minimum 'pull' necessary to scavenge crankcase vapors is ideal. In fact I put a 'restrictor' in the rubber line to the PCV valve to reduce the 'pull' to optimize the system.
Its worked great for like 5 years now...
Crankcase vapors are scavenged (sucked out) of the lifter valley (through the tomato can vapor separator) into the PCV valve which meters the fouled air into the intake via manifold vacuum where it is burned with the fuel mixture. The vented oil filler cap allows air to be drawn into the system from the outside to compensate for what is sucked out of the crankcase and burned.
I went with the Standard SIV-100 (or Fram-FV100 or NAPA 2-9255)...you don't want the normal vacuum affected more than a factor of 2; actually the minimum 'pull' necessary to scavenge crankcase vapors is ideal. In fact I put a 'restrictor' in the rubber line to the PCV valve to reduce the 'pull' to optimize the system.
Its worked great for like 5 years now...
Crankcase vapors are scavenged (sucked out) of the lifter valley (through the tomato can vapor separator) into the PCV valve which meters the fouled air into the intake via manifold vacuum where it is burned with the fuel mixture. The vented oil filler cap allows air to be drawn into the system from the outside to compensate for what is sucked out of the crankcase and burned.
Last edited by Frankie the Fink; 06-20-2014 at 06:52 PM.
06-20-2014, 06:55 PM
#10
Team Owner
06-20-2014, 06:59 PM
#12
Team Owner
Threaded part goes towards the carb. This is my rig with the PCV on the back of the original rear carb on a dual quad '61.
06-20-2014, 07:09 PM
#14
Team Owner
If you think the PCV setup is causing your problems you could put a plug in your carb base where the PCV valve goes and just leave the road draft tube open to atmosphere for a quickee test. This essentially takes the engine back to the stock configuration (or very close).
If your bucking and backfiring clear up then something in the PCV setup is the issue.
If your bucking and backfiring clear up then something in the PCV setup is the issue.