I have oil coming out of the dip stick tube under heavy acceleration. The 8BA is used in vintage drag racing. What could it be?
you may be able to minimize it with a pan vac system also be sure the dipstick seal is good i ended up with a pan vac system on my drag car and a dipstick seal corrected most of it the vac system stopped the rest you just have to know it will **** a bit of oil out with the pan pressure
> >heavy acceleration. The 8BA is used in vintage drag racing > Try lighter acceleration. It's gonna lose to vintage stovebolt 6s anyway.
I agree with the others about venting being in adequate. Also do you have a spring or clip to hold the dipstick down?
On my (french) flatheads there is a rubber bung which gets expanded when the dipstick knob is turned clockwise. Thus this possible exit is completely air- (or water) tight. On my blown flathead I am sure I have a bit of blowby but the crankcase vent is open so there is no pressure on the dipstick.
Has it always done it? or has it gotten worse over time? An answer to those questions might help point toward the possible cause.
You could use a 0-10 or 15 psi gauge to see of over pressurized pan from blow by or Vent to small . Typical engine has 4 psi in crank case . Remove dip use hose & gauge . Check vent size like others said .
If you prevent the oil from coming out of the dipstick tube without correcting the crankcase / blow by problem it`s going to find another outlet. Creating more problems.
Never mentioned the oil level in the pan? If it's up near the full mark the crank might be slapping oil during hard acceleration. Might want to keep oil level down a half quart.
Yup, same. That's why I asked above. Cheapest and easiest flathead improvement there is Imho.... Fixed other stuff too. No g***y smell wafts fr under the hood at stop lights. Lake pipes don't black up, etc.
The high the CR in the chamber, the higher the pressure in the crankcase. It blows out gaskets and seals, drips and smells. It also robs the engine of horsepower as the pistons have to fight that pressure everytime they slide down the cylinders. Add a PCV valve and you be happy you did. On an 8BA it goes in the road draft tube hole where it lines up with the crankcase vent tube under the intake. I bought this one. The adapter has an O ring to seal it, and the valve is from a late model jeep so you can stock up on them. 1949-53 Ford Flathead PCV Valve Conversion
Think of it like a soda cup with a lid and straw. If the soda is coming up thru the straw, the pressure in the cup is enough to push the soda up and out of the straw. Vent the cup. PCV is not original, a road draft tube is, but if it's been modified and you can get a good kit, I'd suggest that as the fix. If the engine has excessive blowby, that may not cure the issue. This applies to any engine.
Everyone's on the right track here, but IME once the blowby reaches a certain point no amount of PCV is going to take care of it. If the rings are shot, if they're stuck, if the cylinders are worn, then blowby is going to happen, and there's nothing you can do but rebuild the engine. Surely try adding PCV first, but if it doesn't address the problem you know what you have to do...
@twenty8 Completely true. I tried to cover the basic question in a general way. The issue of the dipstick could be handled by a locking stick, but would not address the root cause (crankcase pressure). I haven't dealt with tech at an event where they have a lot of flatheads or other engines without PCV. Most racers do not have operational type 4 PCV. I know coolant overflow is not allowed to just vent to the track, but do not know if they check and enforce the same for crankcase. I have not seen this for trans and axle vents.
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