PVC valve installation on 1961 - Hood air cleaner clearance

[Willis]

I am just about to install a rebuilt engine in my 1961, it was manufactured with a down- draft ventilation. I can order a 1962 PVC valve set-up, with a carburetor spacer with the vacuum tube. I read in the forum that because there is a difference in intake manifold dimensions,between the 61-62 there may be a hood clearance problem using the "62 plate. With engine out I don't have anyway of determining how much clearance there is between the hood and air cleaner. Does anyone know the clearance measurement? Has anyone been here before? Is there a real need to update to a PVC valve over the travel-down- draft?

[Joe Johnston]

No real "need" to do the PCV conversion now or latter for that matter. I changed my 57 and eliminated the down draft tube as it also eliminated fumes and an occasional drip. This just just plumbs the crankcase fumes into the intake to be burned instead of directly vented to the underside of the car.

[jrfjr]

Hi, I can't address specifics as related to clearance, etc, but in general, I think it is a really good idea to fit a decent PCV system.

My first car was a '60 Ford Starliner (wish I still had it!). It had a draft tube, and had spent most of its life driving around town at low speeds. When idling at a stop light, large amounts of nasty smoke would come out from underneath, and wrap around the front of the car. I could never get it to run right.

No doubt the rings were shot, but when I rebuilt the engine in 10th grade (1975) auto shop, I found the engine was full of crud. Oils were not great back then, and that also probably contributed to the sludge build-up - there was 3/8" covering the lifter valley. My shop teacher pointed out that most of the trouble, in his opinion was due to the lack of a PCV system, and also probably due to not properly maintaining the car as it aged. He pointed out that PCV systems were fitted to delivery vehicles long before the gov't mandate because they spent a lot of time idling, and without the PCV system, the engines would need to be overhauled more frequently. The draft tube only works when the vehicle is moving fast enough (25mph?) for air to move across the face of the tube, causing a vacuum to pull out the blow-by combustion products.

Anyway, my $.02, and worth what you pay for it. I also realize that once restored, these cars probably won't be used as regular transportation, and in a lot of cases, originality must win out. Good luck. Jim

[bbogue]

From my experience, trying to convert a 61 to a 62 type PCV system is a non-starter due to the thicker carb spacer causing hood clearance issues...apparently a taller intake on the 61's. Do a search on this forum of road draft tube to PCV conversion and you will learn a lot. FWIW, there was a PCV system available for 61 cars. You can simulate that a lot easier than the 62 type. I have something similar to the 61-type on my 61 (no hard tubing) and it seems to work just fine. One member fabricated something very similar to the 61 system using hard tubing. From his pictures I don't know how much closer to original anyone could get.

Good luck.

Bill

[Willis]

Thanks for the quick responses. I've ordered the '62 PVC set-up. I'll compare the plates and proceed with caution. The hood/aircleaner clearance must be less than an inch. I wish there was another '61 around here so I could put a ball of Play Dough on the air Cleaner to get clearance. One of the reasons I purchased the car is because it is rare, I haven't seen one In the Coeur d' Alene Idaho, Spokane Wash. area; of course if I had done better planning I would have had the information before I took the engine out. Your timely advice probably saved me misery and money. Willis

[Willis]

i am a new member of VTCI so the advice to check the past forum information on "down draft/PCV valve" conversion was great. The (California) intake manifold connection looks clean, but I would like to here about any down-side to this modification (vacuum from the manifold port) before I proceed. Willis

[bbogue]

Willis,
While your engine is in pieces you might take a look at the PCV intake manifold hole in front of the carb. I think you'll see that it feeds at most a couple of cylinders. This "unbalanced" flow of crankcase fumes from the PCV I think is a non-issue unless there is significant blow-by. Just my opinion. I would prefer to introduce the crankcase vapors via the carb spacer for more even distribution but I couldn't make it work with a 62 carb spacer. A drop-down air cleaner might have worked but the stud on my stock Autolite carb would have been well into the hood insulation, possibly into the hood itself, I don't recall the exact degree of interference. My installation was further complicated by 1/4" spacers added at the motor mounts due to the headers I installed.
Good luck.

Bill

[Alan H. Tast]

If you're intent on using the '62-'63-style PCV system with the spacer, PCV fitting/tube/hoses, and hose nipple on the rear of the intake, I'd recommend that you find a used '62-'63 intake and swap out the '61 version. You can swap out the intake with a few hours' worth of time and be sure that it will clear the hood. Using the taller '61 manifold with the '62-3 spacer will create a problem since it will raise the carb at least 1/2-5/8".

And if you're intent on using the '62-3 system on a '61 manifold, you will need to cut down the height of the air cleaner stud and look into finding an aftermarket open-element air cleaner and look into a variety of short air filter element heights to "dial in" your clearance. Personally, I'd look into the repop open element air cleaners marketed for '63-'64 hipo Falcons/Fairlanes and very early '64.5-'65 Mustangs - that's what I used for my car when I had an aluminum intake mounted on it.

[Willis]

Now that I have all this great information I'm probably going to put the PCV valve set-up I ordered on the shelf until I can find a '62/'63 manifold then change the whole thing out. Does anyone know if the late '62/'63 manifold will interchange on a '61 engine, with only the hight being different? Are the '62/'63 manifolds the same? I'll have to put it back to stock to get it out of the mechanic shop for now. I appreciate everyone who took their time to write about my issue; it allowed me to make informed decisions .

[tbird]

The 62/63 manifold will fit on to your 61 engine without modifications.

[bbogue]

"You can swap out the intake with a few hours' worth of time and be sure that it will clear the hood."

I am sure some of the more experienced members can do this in a few hours. No disrespect intended. Alan's experience and knowledge can only be admired. But this is not for a junior mechanic like me, with a minimal garage, and without a more pressing need. I hear that these manifolds weigh about 75 lbs and that great care must be taken to clean the gasket contact surfaces before installation, else there will be leaks. I also hear that some of the intake gaskets are not used, some sort of sealant instead, which one? If you do this please research it thoroughly before you do so. And then there is the somewhat controversial benefit of the coolant flowing through the carb spacer. For me, with a newly rebuilt engine a therefore minimal blow-by, the 61-type PCV system is plenty good enough, and it's more original to the car. Also, should you replace the carburetor at some point, it is likely that the replacement will have a PCV port.

Best of luck whatever you do.

Bill

[GeoffInCarlsbad]

So for my two cents, I am tying my PCV to the Vacuum Pump Exhaust port that is behind the distributor and in front of the carb. If you have the 1961 Shop Manual, you will find a picture of this set-up there. I have included it below along with pic of where it sits in my intake manifold.

I do have some minimal blow-by, and my hope is that the fumes will burn or exhaust out through the exhaust systems.

[Alan H. Tast]

"You can swap out the intake with a few hours' worth of time and be sure that it will clear the hood."

I am sure some of the more experienced members can do this in a few hours. No disrespect intended. Alan's experience and knowledge can only be admired. But this is not for a junior mechanic like me, with a minimal garage, and without a more pressing need. I hear that these manifolds weigh about 75 lbs and that great care must be taken to clean the gasket contact surfaces before installation, else there will be leaks. I also hear that some of the intake gaskets are not used, some sort of sealant instead, which one? If you do this please research it thoroughly before you do so. And then there is the somewhat controversial benefit of the coolant flowing through the carb spacer. For me, with a newly rebuilt engine a therefore minimal blow-by, the 61-type PCV system is plenty good enough, and it's more original to the car. Also, should you replace the carburetor at some point, it is likely that the replacement will have a PCV port.

Best of luck whatever you do.

Bill

I should have been a little clearer with my response. The time it will take to hunt down fittings, fabricate the tubing, brackets, etc. to replicate the '61 system probably will be close to the same as you'll spend to replace the intake manifold and add the '62-3-style PCV system. Obviously it would be easier to leave the '61 manifold in place and fabricate the pieces needed for the system, but you will also have to find and swap out the fitting at the back of the manifold to get rid of the draft tube. From a time standpoint I think it would be a wash, but from an authenticity (or close to authentic) standpoint, as well as being easier to do without swapping intakes or fussing with trying to find a non-original air cleaner/filter height combination that would work, I'd recommend to replicate the '61 system as shown in the pages from the '61 Shop Manual.

[Willis]

I want to thank everyone who has offered advice on the PCV issue. I've learned a lot about the car but more about how valuable this forum is.

[Ozzy351]

Willis, if you are interested, here are some photos of the PCV system I fitted to my '61. The metal tube and valve itself were relatively easy to find via Ebay and are NOS items and were inexpensive. The rubber hose is off (dare I say it) a Toyota 4 x 4 and was readily available from my local radiator hose shop. A few inches just needed to be trimmed off to get the correct length. The more difficult item to find was the brass intake fitting and the most difficult, the metal tube with the hose fitting that fits into the rear of the manifold where the draft tube fits. Both of these last two items were generously sourced for me by Jim Wulf. He did stress at the time that the rear manifold fitting is getting extremely hard to find nowadays.






Ozzy