I'm on a real question posting roll today! I have a 1955 Cadillac 331 in my roadster, and its having a big oil issue: I'm getting lots of oil puking out the breather at higher RPMs. Its actually gurgling out of the oil fill tube and all over my cowl; And I'm not burning oil out the pipes. I bought the engine running and driving but here's what I changed: Stock valve covers had a 1/4 hole on each with a tube running to the air cleaner. The valve covers are now pre 55 script style, but we tapped small breathering holes in the back of them. I also replaced the valley pan with a non- baffle, non breather finned version... Could this be part of the problem? Would this cause oil to puke all the way out the fill tube? Anyone else ever experience this? What else to check? Thanks, jay PS- Anybody got a set of old, chromed script valve covers lying around?
Oh, the motor is definitely got miles, but it doesn't burn oil- It runs about 40 PSI at RPM- This is a weird pressure problem that forcing the oil flow out of the breather
Is there a baffle in the fill tube? When I shortened mine on the S2D motor (Very similar) I pulled out the baffle and pushed it into the shorter fill tube. TZ
Although I am not familiar with the exact details of the early Cad engine, I tend to agree with the thought that you have too much blow-by causing the crankcase to become pressurized and causing some oil to get blown out the tube. Does your engine have a draft tube? Is it open and clear? Is your new breathers in the end of the valve covers connected to manifold vacuum? Like a PCV is? I think the baffles in the valve cover breathers and valley pan could have a lot to do with it. Your oil pressure does not really affect this problem if it is blow-by crankcase pressure.
you're supposed to have a road draft tube,right? my '61 cad has one.you might have to mill and drill a spot in your valley cover to re-install the road draft tube.or do some real breathers on the valve covers.yes,i know all about how hard you had to look to find the earlier cursive script ones...
I put a Moon finned aluminum valley pan onto my '59 Caddy mill about three years ago and had to make a slight mod to it. Here's how it goes....Moon doesn't give you a provision on the valley pan for the road draft tube, but you need something on there to get the pressure out of your crankcase (this is why you have the oil puking). Drill a hole in the valley pan, and tap it for a 90 degree br*** fitting. Go to the hardware store and get some 3/8" flexible toilet tubing (it's about $.50 and it's already chrome) and a nut and crush washer to fit over it. Screw the fitting into the valley pan, put the tube onto the fitting pointing it towards the rear of the motor and put a piece of hose onto the back of the tube. Put a PCV valve onto the hose (I think I used one for a Caddy 500), and a piece of hose onto the other end of the PCV valve, running this end to the back of the carb. The reason for the tube was so I could get the PCV valve to the back of the motor so I could change it easily without having to yank the intake. Depending on where you drill your hole, you might not need it. I have Offenhauser valve covers with no breathers in them (just the stock factory oil filler/breather in the front of the motor). This should get the pressure in the crankcase down and get it to stop puking oil. I've run my motor about 80,000 mile in the last three years and it's been great. Let me know how it goes.....
Do I need to run the vent line back to the carb, or could I just run it out the back of the motor towards the ground?
Are you running the stock oil filter? The reason I ask is because I just put a `54 Cad in a A-RPU and didn`t run the filter.First I used a 5/16 hose where the filter went.Oil pressure was up at start up,then dropped to 8/10 after it was warm.Car also blew oil from breather and I`m running the down draft tube.Next took hose off were filter went and plugged holes.Oil pressure shot up to almost 100.Next put filter on and everythings OK. I also have a Tri-power `59 cad in a `34 roadster that has Offie vally cover(no breather hole and no draft tube)I put a Cal Custom 90degree breather on the top side of each valve cover and the breather cap on the oil fill tube(never seen any baffles in them,only fuel pump)It`s runs great,no problems. Don`t know if this helps,but that`s my story. JR... ps...I am having a ***** of a time with the dual quads on the RPUs 331. They are very blubbery,poping,farting and running rich.I changed them to progressive linkage and it got worse.Need to go back to direct linkage and sort it out. It`s not a fun driver now,I`d hate to go to a single 4brl. They are the oringinal Carters.(WFB?) QUAD GUYS ANY TIPS?
I`ve seen a few Caddy and Olds motors running 90 degee breathers near the top of there oil pans.That might help? JR...
Instead of running a line to the back of a carb, you could drill and tap a vac*** hole into the back of the intake where no one can see it. Blownranger - what intake are you running the dual quads on? I'm running a Weiand dual quad with 2 new carter AFB's (600 cfm each) with adapter plates on the intake and it runs great (non-progressive - I never tried it the other way).
Stock `54 El Dorado.A 20,000mi motor and oregion carbs. Factory intake.Sent heads out for a valve job,new timing chain,and pertronex ing.Motor was clean as a whistle inside. Would love to find Edmonds 2x2s. JR...
I looks like you have the option to run your vent to the carb or to the ground. Does the draft tube just direct the g***es to the ground or is it designed to draw with vacuum like the intake does. I heard the theory behind the draft tube is a vacuum is caused by the air rushing under it, drawing out the fumes. If this is true a rubber hose might not cut it. TZ
Install the PCV valve. That should take care of the problems and also keep the oil mess off the area behind the road draft tube. I installed one into the back of the front carb base on my dual quad setup. Seems to work well so far. warbird
hey JAY. INSTALL a TUBE dropped axle, and one of those FAKE quick change rear end covers....... OH and if that doesn't fix it...... call those GUYS at BILLETPROOF, they should also be able to HOOK you up with 305 small block, a MAIL TRUCK, a JEEP, and a CHOPPED VW, with RED RIMS,,, oh and some MIKE NESS AUTOGRAPHS KIRK! was selling on ebay... that should probably cure your PROBLEM.. if not maybe you can get some of those CHROME EDELBROCK 305 covers from RICKYRACERS,, his MEXICAN *** cut three holes in each one and they have SIX breathers,, SOMETHING about his DRIVE to BILLETPROOF, pulling the trailer filled with COWS for FASHION show ,,,, he said the WEIGHT was causeing his motor to need more breath... XOXOXOXOX germ
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