I have an original 63 fuelie. The problem is that engine oil is being sucked into the dog house through the PCV valve from the vent tube at the rear of the engine. Apparently at high speeds after there is enough oil in the dog house it is sucked into the cylinders and a huge smoke ball will come out the back. Today I took the car out and was powering up on a good straight run and at about 110 MPH, the smoke came boiling out the back. When I got back home I took the top of the doghouse off and there was a pool of oil in the doghouse. Here are some additional facts: I have previously put a new ballast can in the oil galley that is suppose to keep the oil sloshing from being sucked up the back vent tube that is hooked into the PCV. I also put in a new grommet on the rear vent pipe. Other than powering over 100 MPH, the car runs great. Has anyone else had this problem? I am open to ideas and suggestions.
-
-
Re: Help! I have a 63 Fuelie Problem
The same basic PCV architecture was used for all '63 engines. The correct valve is Delco PV590C or equivalent.
Have you checked the valve to see if the spring is intact and the valve basically functions?
What you refer to as a "ballast can" is called a "ventilator" by GM, and it's basic purpose is to function as a liquid-vapor separator, so liquid oil doesn't get pulled into the inlet manifold.
My L-76 would put out a cloud of smoke at times when it was fairly new and I got on it hard - I think due to excess blowby because the chrome rings took a long time to seat (I may have broken it in too gently.). It finally settled down at about 10K miles. Modern moly faced rings seat much quicker.
Oil ingestion via the PCV system can be problematic on any car (I had to redesign the system twice on my Cosworth Vega to find an architecture that didn't ingest oil), and it's even been a problem on late model Corvettes. The first thing to check is that the PCV lines are properly routed/connected/clear of obstructions and check that the valve is clean and functions. If you suck on the downstream side, the valve should start to close and restict the flow of air. If you blow backwards, it should not flow. This is the anti-backfire feature that is required on carbureted engines to prevent an inlet system backfire from propagating to the crankcase and causing and explosion. Since blowby is mostly unburned air/fuel mixture, it is combustible. This anti-backfire feature is not needed on port injection engines because the manifold is not "wet", which prevents backfire flame from propagating far up the runner, but it does no harm to have an anti-backfire device.
If the above checks out it could be excess blowby. The first thing to do is plug the fresh air inlet and disconnect the outlet line from the PCV. Then blip the throttle hard and feel for excess flow. If the flow appears to be high, run a compression check.
Some modern EFI cars do not have flow-through PCV systems. In other words, there is no fresh air inlet. The crankcase is merely vented to the air cleaner or throttle body. In the case of my '91 MR2 a hose from the cam cover (which has a liquid vapor separator built in) routes to the throttle body, which has a small resticted passage to below the throttle plate and a larger passage to above the throttle plate. This allows for a small but constant depression to keep crankcase pressure from building up, but not enough depression to draw a significant vacuum in the crankcase.
The OE system on my CV had a fresh air nipple on the air cleaner that routed to the bottom of the block, and the windage tray just inside has a liquid-vapor separator, but it didn't work and pushed oil into the air cleaner, especially under high dynamic loading and high revs at the track. The outlet was a nipple on the cam cover that routed to a valve and then to the inlet manifold.
My second design plugged the block inlet and replaced the outlet hoses/valve with a hose from the cam cover nipple to the former air cleaner fresh air inlet. It also includes an "oil trap" - a tee in the line with a clear vinyl tube that routes to the bottom of the car. The tube is plugged, but is easily accessible to visually inspect for oil and drain any oil accumulation. I do get a fraction of an ounce of oil in the tube once in a while, but no oil in the air cleaner and no blue smoke.
You could implement a similar architecture on you car by removing the outlet plumbing including the valve and plugging both the port in the plenum and outlet at the rear of the block. It wouldn't be to hard to setup as an experiment.
Blowby will then vent to the air meter inlet via the line that was the original fresh air inlet. No valve or anti-backfire device is necessary since the plenum is dry and a backfire flame will not be able to propagate to the air meter inlet.
I proved that this system architecture doesn't need an anti-backfire device on a port injection engine as I experienced a number of backfires on the CV after I reindexed the cams and was suffering from an excessively lean mixture. The analog ECU has several simple adjustments that allowed me to tune out the leaness, but before I got it dialed in I had several backfires, but no crankcase explosion.
Duke -
Re: Help! I have a 63 Fuelie Problem
Hi Pat, It's probably the weather in Alaska causing the problem. My answer is not near as sophisticated as Dukes and may not help at all. I agree with Duke when he said to temporarily remove the pcv and block the holes up. It should solve the problems if your rings are seating and installed properly. Make sure you have a "real" PCV and not a replacement first of all. Then don't use one of the blackened ones we need for judging. When you blacken a part you actually rust it. I have had trouble like yours with these valves and now I cheat. I actually seal off both ends of the valve and just blacken the outide. I remember having a early '64 FI car do the same thing as yours. Sent him a new shiny valve and he said it fixed the problem. My '63 will never reach 110 mph going on and off the trailer and I'm to old to drive that fast anyhow. Remember that this car is not one of those rockets you know all about. Slow down. JohnComment
-
i know of a guy who overhauled his engine because
it used oil and it still used oil after the overhaul. replacing the PCV valve with a genuine GM stopped the oil burningComment
-
Re: i know of a guy who overhauled his engine beca
Clem, Since you are finally an NCRS member why don't you come to the Pittsburgh Chapter annual show tomorrow morning at Kenny Ross Chevrolet. We are having an indoor show and have 12-14 Corvettes to judge. We could use your expertise in selling 50-50 tickets. Thanks for the answer on the PCV valves. I can recall having at least 4 or 5 complaints about these valves over the years. If I had a car I was driving a lot I would probably eliminate it like Duke said. Please come to the show as I am sure we would love to see you. A lot of your old friends will be their. All are invited. We are having a barbecue lunch also.
Dave Kitch put a notice about this event recently about a judge shortage. Thanks to surrounding chapters we made the quota.Comment
-
off to chuch sunday because mrs clem
says i can use all the help i can get.thanks for the inviteComment
-
Ahhhhh, Mrs. Clem very wise lady. *NM*
Comment
-
she has tried for 47 years,some one elses turn *NM*
Comment
Comment