When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have been going through making necessary fixes to my newly acquired 442. When I got to OAI air cleaner I noticed numerous issues after referencing an assembly manual.
Based on my research it looks like I do not have the proper intake manifold for an OAI application. Need you all to confirm. I believe this because it looks to be missing the PCV hook up that goes from the manifold to the back of the carb.
All real 1970 W-30 motors used two breathers (one in each valve cover). The PCV valve was routed from the FRONT of the carb to that nipple. A real W-30 intake will have the nipple installed. If yours does not, then it's a repro.
In any case, only W-30 cars used that intake and that PCV setup. The W-25 O.A.I. system was available on any 442 with the stock iron intake. For AT cars, the PCV was in the valve cover and only a single breather from the other valve cover went to the air cleaner.
Of course, your aftermarket Holley carb won't have the same PCV connections as the original Qjet anyway, so this is all moot.
ebay has the 90 degree elbow, i'm not sure if the exact pcv valve is available new. if the holley has a large vacuum port at the base you can probably route a longer hose to it. if you return to a quadrajet, try to find an early 70's unit with the correct pcv tube fitting in the front. forget an original w30 carb, they are going for about $3000 now. nice car, good luck
I've never seen one of the aftermarket W-30 intakes up close. Not to trash your car but whoever makes them they sure did a sloppy job on the "Olds W-455'. Olds used a pressed in steel nipple on those intakes but no one is repopping them that I know of, only the rubber 90 degree piece that slips over it. You could pull the intake,drill a hole & thread it for a short 1/8" pipe nipple. The o/d of the nipple is close to the diameter of the factory steel one & the rubber piece covers it so you won't see it. But like Joe said I wouldn't bother unless you can find a Q-jet. Your car appears to have "F" heads on it but they're not unfortunately. The casting # on your head is 403686. That is the infamous "E" head that had the bottom of the E ground off to make them F heads. The correct casting # on a W-30 F head is 404438
Thanks everyone for the help. Of course you generated more questions
The intake is an edelbrock reprod. This is a non original engine and it looks like the last owner put stuff together to make it work. As Joe noticed the Holley. Unfortunately my partial build sheet that I found did not indicate whether this was a OAI optioned car.
My goal is to make it as true to the original as I can without breaking the bank. Since I have most of the OAI stuff I will go that route.
For OAI w25 cars how was PCV setup? If you all can recommend a better book on this subject I would welcome that. The GM assembly manual is lacking on PCV setup hence my post.
My goal is to make it as true to the original as I can without breaking the bank.
Not to criticize, but by definition, "original" means that particular car is as it was when it left the factory, with the parts that were installed on it then. That ship has already sailed in your case, since the original parts are apparently long gone. If you want to be factory correct for a 442 with the W-25 option, fine, but your car is a long way from factory correct and will take a lot of money to make it so.
First, it isn't a W-30, but it has numerous "unoriginal" faux W-30 parts, most importantly the fake "F" heads that were fabricated and an incorrect repro intake that isn't even close to original. If your intent is to build a correct W-25 442, then you need to lose the aluminum intake and bogus heads for starters, since non-W cars came with E heads and an iron intake. If your intent is to build a W-30 clone, you need correct (and extremely expensive) F heads and intake. I also suspect (though you didn't provide a photo) that the car has the wide W-30 side stripes, since just about every 1970-72 442 now has them. These would not be correct for a W-25 car either.
You see where I'm going? Your car will never be "correct" without a massive infusion of cash and parts (and frankly that will not be a wise investment if you are concerned about resale value). I'd suggest that you do the things that make you happy and enjoy the car as is. If a correct PCV routing makes you happy, then get a Chassis Service Manual, which shows the PCV routing for both AT and MT versions of W-25 cars. I'm pretty sure that diagram is in the assembly manual also.
The reality is that 99% of the people who see the car won't know what is correct or not, and if you are concerned about OCA or AACA judging, you will need to spend thousands of dollars to get there. Good luck with whatever choice you make.
Thank you all for the help. Joe you are correct on the striping. When I go back for a repaint it will be repainted to the original black and I will have the W30 stripes removed.
This has been a fun learning experiencing and I truly appreciate the additional help. I will research and come back if I have questions.
Additionally thank you all for the compliments on my car.
October 22nd, 2016, 04:14 PM
