Anybody ever do their own? my buddie gave me an intake that has the boss. it just needs to be drilled. what size bit do i need? i have a drill press. what else should i know?
they did it in old skool rodz once for the wagon project, outlined the whole process. i don't have the article, but someone there may?
I'd make it about .005 smaller than the tube you want to use. That should be enough sqeeze to keep it in place. You want a good stright round hole. If it is not round the tube may slip out.
I bought a 350 sbc once and the intake ,which was an edelbrock performer, had been drilled for the oil tube. The oil tube was a after market chrome piece that didnt have a tight fit. I mean it fit ok, but wasnt like the original. I thought it might become loose and fall off onto the fan when in motion. Anyway i wound up selling it...
I did it. Clamped the manifold to a work bench. I then used a hole saw bit that was an 1/8 smaller than it needed to be. Cut the core out. Just used a hand drill and watched the angle it needed to be at. Then I bought a big jobber twist drill bit just under the size of the tube of ebay. I forget the size - something like 1 27/48 or something. I can check the actual size later if you need me too. It was 18 bucks. Used that jobber drill bit to get the hole real close. Then it was a matter of barrel sanding the hole with a die grinder to get the right fit. It was my expensive as hell 4-71 SBC manifold. Needless to say I was a bit nervous but it worked out fine. I saved that core. That part was a muther. Just do it. Good Luck I read that article in OSR and it didn't seem to help much if you ask me.
Yes, my son and I did it to a performer manifold. We drilled a small hole in the center of the boss from the bottom upwards. Then we used a large step bit and slowly worked it bigger. When we were close we used a die grinder and went very slowly for a nice tight final fit. It turned out very good. I didn't want to do it to a new manifold... but it looks nice on his 1963 283
I would advise against going too close to the exact size with the hole saw. My experience was the hole saw cut a little fatter than its diameter. Good Luck!
Try the hole saw in a s**** of aluminum first and check the size with your dial calipers, if it cuts a bit large then all you have to do is dull the teeth on the outside of the cutter. Even a slip fit should be fine, what with all the space age adhesives on the market.
Though it is not exactly precision or preferred, you can file it out to size once you are close. We did that on my son's aluminum intake after drilling with the largest bits we had. Filed it out carefully and then used some silver rtv sealer to cement the chrome tube in carefully to make sure it would stay put. Worked fine. This would also work to address a loose aftermarket chrome tube.
I drilled a performer with a huge drill bit. It wandered a little so I had to secure the tube with epoxy. Its still there 10 years later. There was a thread on this yesterday, I believe. Dave
Late to the party, but I did the same thing on mine, so for anyone else-- The "kerf" of the hole saw teeth is going to take out more meat than the advertised diameter of the saw. As Tudor said, sneak up on it. I cemented mine in with JB Weld when I was done, not just to hold the oil fill tube in, but to seal it as well--I've noticed oil seems to weap around fill tubes. -Brad
That looks great. Only one problem. Looks like you aren't going to run an air tube+PCV or breathers in the valve covers. You need one or the other. The early engines had a road draft tube on the back. Air going by the tube caused low pressure, drawing "bad" air out, while "good" air came in thru vented cap of oil fill on front of engine. In '62, Corvettes did away with the raod tube and put a PCV in-line from the back hole to the base of the carb. The oil fill got a ****** added to the tube, and a sealed cap. A hose was routed from the air cleaner to the oil fill ******. A PCV system going front to back (solid valve covvers) instead of the common side to side using connections in the valve covers. You are going to need another vent somewhere to draw out the "bad" air in the bottom end. Here are two pics, one shows the original draft tube laying on the manifold and you can see the Corvette style oil fill. The other shows the replacement fitting, where the road tube used to be, that Corvette's used to hook up a PCV inline to the carb. Tony
I did it on a 3x2 intake once - as others have said, I used a hole saw. Got it to be a snug fit & usd JB Weld to ensure it wouldn't fall out.
o.k. now i'm confused. so i need to vent the motor in another spot? can i do this off the manifold? i went through all of this so i would not have to cut up my vavle covers. please help.
You need fresh air in and vacuum (or the draft tube-which is arguably worthless) out. Usually a pcv valve comes from one valve cover to a vac*** on the carb. There is another thread on here about drilling a hole for a pcv valve in the rear of the intake so you can hide that too. Anyone have it saved?
Glendale, I understand wanting to run solid valve covers. They look great. I am not trying to tell you what to do, or that what you have done won't work. Just wanting to give you a heads up. I'd hate to see you have problems down the road. To get the air out of the bottom end there has to be draw, like a chimney pulls smoke out of a fieplace. Either low pressure created by air rushing past draft tube, or manifold vacuum just below the throttle plates. Draft tubes don't work when the car is sitting still, they pollute, smell, and tend to drip oil. PCV much better. The oil fill tube you installed probably has a vented cap. That should be your input side, now you just need a low pressure source to draw the air out. You probably don't have the spot behind the manifold for a draft tube. You can hook up back there by porting the manifold into the valley. Somewhere close to the distributor hole, but not into a intake runner. Run a line from there to an in-line PCV (search the shelves at O'Reilleys), then to a port below the throttle plates. Tony
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