COMET CENTRAL

I have been away for a while, but I have a question about a 406. It has a six pack set up, but there is no large vacuum port on the rear carburetor. Whoever built the motor/car put a 90 degree fitting on the back of the intake and a 5/8" hose that hangs off the back of the motor. Oil dumps out on the ground and all underneath the car. Any help with how this motor should be properly vented would be greatly appreciated.
Thanks in advance.

You can see the vacuum port for the power brakes, but no port for the crankcase. The hose off to the left is just an open hose

Is the oil cap in the valve cover vented ?? pop

Yes, both caps. Hope you are doing well Pop

I would think that the hose should go over to a cap in V cover with a pcv in the oil cap & the other side v cover a breather oil cap/or hose from oil cap up to carb air filter so engine gets clean air .

Yeah, I think that's what I have decided to do. I need to tap the breather for a 5/8" hose

I was thinking the VC's on a 406 were smooth....pop

I'm not sure if they are original for that motor. I have seen several with that valve cover though. It's a 61 motor in a 66 Fairlane

These are the ones I use on both sides. just took out the pcv valve from driver side, put a hose up to bottom of air cleaner. doesn't get messy like the little breathers. So I now have a spare pvc for the pass side one ,hose to back of intake. kinda pricey. there are cheaper ones.
https://www.summitracing.com/parts/bsp-21120/overview/

BTW, We have a new section for comet's sister cars, we'd love to see more of that fairlane!!

The orig 406 valve were smooth with no caps.Oil was added through a stand pipe on the front of the intake with a vented cap.The hose in question was basically the way yours is now. What I would do is cap off that hose fitting,put a T fitting where the booster fitting is now and run a hose with a PCV to one of your vented caps and a filtered cap or the air cleaner deal you talked about on the other cap. There really shouldn't be that much oil coming out of that hose. It might be a sign of excessive blowby.A leak down test is probably in order.
That said,the 406-405 is probably my favorite motor of all time. Had a 63 Gal with one that would rev to the moon.Nobody really knew what it was all about (including me) since we lived in Chevytown.Sold it for 500 bucks!

vicegrip wrote: That said,the 406-405 is probably my favorite motor of all time. Had a 63 Gal with one that would rev to the moon.Nobody really knew what it was all about (including me) since we lived in Chevytown.Sold it for 500 bucks!

$500, i bet you wish you could have that back.

Thanks Vicegrip, I am most likely going that route. The car doesn't belong to me, but I am suspicious of the condition of the motor. My main goal was to get the carbs working right, but the linkage may need some modifying, but I want to get the venting problem solved too.

IF I had it to do over,instead of building a 390 for my 66 f100 ,I would have punched the 352 to a 406 ,as I have the 1963 406 tri pwr heads and the 3x2 set up,even the correct air cleaner,but I knew I had the standard bore and standard crank for the 390,so's I built the 390 and used the 406 heads on it with a 428 1966 PI single 4bbl alumn intake,with a holly....runs great,,but I wish I'd built a 406....pop

First off I am not an expert on FE motors. I have only worked on a few. My sister had a 406 in a early 60’s Merc. I worked on. It had a road draft tube off the back of the intake that bolted in the back of the intake were the plate where your 5/8”ftg is. The road draft tube was shrouded or had a baffle to keep oil splash from lifters splashing oil up the tube. I would pull the fitting out and put some RPM’s to the motor and see if oil is splashing out the hole. I would do it with a warm motor. Oil splashes more when it’s hot. If it splashes out baffles could cure it. If it comes out as just smoke it needs engine work.

popscomet wrote:IF I had it to do over,instead of building a 390 for my 66 f100 ,I would have punched the 352 to a 406 ,as I have the 1963 406 tri pwr heads and the 3x2 set up,even the correct air cleaner,but I knew I had the standard bore and standard crank for the 390,so's I built the 390 and used the 406 heads on it with a 428 1966 PI single 4bbl alumn intake,with a holly....runs great,,but I wish I'd built a 406....pop

Pop, I bet it will light the tires up on your truck. Post a good burn out video for us.

StPro wrote:First off I am not an expert on FE motors. I have only worked on a few. My sister had a 406 in a early 60’s Merc. I worked on. It had a road draft tube off the back of the intake that bolted in the back of the intake were the plate where your 5/8”ftg is. The road draft tube was shrouded or had a baffle to keep oil splash from lifters splashing oil up the tube. I would pull the fitting out and put some RPM’s to the motor and see if oil is splashing out the hole. I would do it with a warm motor. Oil splashes more when it’s hot. If it splashes out baffles could cure it. If it comes out as just smoke it needs engine work.

It's definitely kicking oil out. I have tomorrow off work, so I will see what I can do with it. I had a 428 in a 56 f100, but I never had any issues with oil leaks. I only had the truck about 6 months, and I hardly drove it, so I never really noticed the baffle or vent tube from the back of the intake. That was 30 years ago too