My car only had the valve cover breathers, and I got tired of oil getting pushed out of those, along with the intake and dripping from the pan seals. I tried a PVC set up to the back of the intake, and the car didn’t want to idle very well, and it looked hokey, same when I ran it to the back of the carb. I am sure someone smarter than me can give me a lesson on duration and vacuum with a long duration cam.
I decided to go with the header evac kit from Jegs (cheaper, but you get what you pay for). I also have some Hedman Headers on the car, they have some weird collectors and clearance issues so I opted to tap the evac valves into he header pipe vice the actual collector. I am changing over to my Hookers one day, and the pipes are cheap and easy to put in. Biggest reason, I had the exhaust system off the car, and not the headers, easy to weld on!
I got the kit, read the directions and sort of followed them. All you need is a stepped drill bit that goes up to at least 1-1/8”, a die grinder or grinding stone for your drill, welder, tape measure, tape and of course the kit and some 5/8 heater hose.
First thing, following the instructions I wanted to ensure my valve cover breather caps were not directly over the rockers or push rods, avoid some oil splash. Although my Canton valve covers are bossed and stamped for breathers, it is right over the rockers and there are no baffles or splash shields in them. I placed some of the easy release blue painters tape down the center of my valve covers. Then I measured from the fire wall to the space between the rockers on the 1 and 2 cylinders, I put the valve cover back on, and used the firewall again as the base line, and marked the valve cover at the distance I had measured between the rockers.
I then measured the centerline of the valve cover at the mark and drilled a small pilot hole. Using my step bit, I drilled a 1 & 1/8” hole in the valve covers. I deburred and cleaned them out really good to ensure I had all the aluminum shavings out of them, put the grommets in and bolted the valve covers back on the car, then pushed the breather caps on.
The header evac pipe nipple is beveled at 45 degrees on the header or pipe end, so I laid it on the header where I wanted it, marked it with a sharpie, drilled a pilot hole then drilled it with a step bit. This pipe has to go into the header/pipe at a 45 degree angle to work properly, meaning the pipe is 45 degrees to the header or pipe and the end of the nipple inside the header is parallel with the pipe. To get this to fit correctly you mark the oblong hole, drill the pipe then grind out the hole to achieve the angle and fit.
Depending on the header collector size, 2.5 or 3 inch etc, the nipple should only extend a given amount inside the header or pipe. My pipes are 2.5 inch and it called for ½ inch extension into the pipe. With the one way valve screwed onto the nipple, I inserted it into the hole and eyeballed how much of the nipple and valve I wanted extending from the pipe (be sure the valve is far enough off the pipe to get a wrench on it), marked it, added a ½ inch to the nipple and cut it at a 45 degree angle. Once all this was cut and fabbed, I took the valves off and welded the nipples into the pipes.
Once it all is welded in, I installed the exhaust, ran the 5/8 heater hose from the breather to the header valve, cut the hose to fit and put hose clamps on to hold the hoses in place.
All but the hose comes with the kit, so it’s pretty simple. The one way evac valves are really EGR valves for a 74 Pinto, why do I know this. When I tested the car, it leaked oil worse! After some good folk on here told me to check my one way valves, I found out one was stuck closed and the other was barely operable. I went to NAPA, and got new valves p/n 29000-06 (thanks CAHORN), screwed them on, and now I have no leaks and very minimal dripping from rear pan seal!
There is a lot of good discussion on this in many forums, a lot of great ideas about vacuum pumps and other systems, this one worked great for me! I do run Flowmasters on my car, and drive it on the street. Even with these mufflers I have good vacuum at the valve cover with this set up.
When I change out engines and go back to my Hookers, I will get a couple of nipples and weld them into my collectors where they should be.
As always, enjoy and be safe.
Gydyup - 67 Mustang Coupe
Today
