1964 F.I. PCV location??

[David G.]

PCV's were placed, as I remember, into the Doghouse base, passenger side, with the return hose running back into the Oil filler tube on a '64 F.I. Doghouse. Does anyone have the exact configuration in a picture or illustration that shows this connection in detail: clips, connectors, rounting of hose, etc. I do not have a 63/64 JM; the years I have are after the F.I. production ceased. In all the many Corvette books I own, I can not find a single photograph that shows the PCV on a '64 Doghouse.

BTW John, this new format is great! Congratulations! Great job.

David Grayson
Saint Louis

[Bill W.]

Re: 1964 F.I. PCV location??

David, I believe '64 and '65 FI cars did not use a PCV valve. They used a metered orfice in the front of the doghouse that was plumbed into the oil fill tube. Filtered air was supplyed to the crankcase vent at the back of the block from a 1 inch tube coming off the air meter adapter. Sorry, I don't have any pictures. Hope this answered your question. Bill

[Duke W.]

Re: 1964 F.I. PCV location??

That's correct - no valve on any '64 and '65 Corvette engine PCV systems.

A design with a valve returned in '66. ('61 to '63 PCV systems had a valve).

The best illustrations of the PCV hardware are in the AIM for each year.

Duke

[Dan H.]

Re: 1964 F.I. PCV location??

Duke, what about the early '375' units?

[Duke W.]

Re: 1964 F.I. PCV location??

I'm not sure what you mean. The 375 FI units were used on '63s. The PCV valve screws into an adapter at the right rear corner of the plenum.

On 380 units plenum this port is used for the VAC.

Early '64s use the 375R unit, but I'm not sure if it used the '63 PCV setup with a valve or the the valveless system.

One the of the FI experts can probably tell us.

Duke

[Dan H.]

Re: 1964 F.I. PCV location??

Duke, Check out page 229 of Nolands book, the top picture is of a 64 with a 375 unit which still has the PVC valve as in 63 model year. Then some 380 units with the front elbow fitting etc.
Dan

[Duke W.]

Re: 1964 F.I. PCV location??

The early '64 engines used a "375R" FI unit, which was a "left over" '63 375 that was recalibrated for the 30-30 cam, and you can see that the 375R retains the '63 PCV design.

I also believe these early '64 FI engines used "left over" 1963 distributors with the '63 VAC and centrifugal curve. I expect these units would have ported vacuum advance unless the air meter was modified from the '63/375 ported vacuum advance configuration.

On the 380 unit the plenum port used by the PCV valve in '63 is used to provide full time vacuum signal to the VAC as you can see in the center photo. The 380 PCV inlet goes from the air meter to the back of the block via the large hose/pip that you can see in the bottom phote. The PCV outlet is from the oil filler tube to the fitting in the front of the plenum and this fitting has a calibrated orifice to control flow when manifold vacuum is high.

Note that the normal PCV flow in the '64 (380) system is opposite the direction of the '63/375 early '64/375R PCV system except at WOT when it can reverse. All '64 PCV systems are of this same valveless architecture, which is a significantly different design than earlier systems that had valves.

Duke

[Mike L.]

Re: 1964 F.I. PCV location??

On a 375R fuel unit the PCV is located on the pass. side, same place as a 1963 375 unit.

[Michael H.]

Re: 1964 F.I. PCV location??

I also believe these early '64 FI engines used "left over" 1963 distributors with the '63 VAC and centrifugal curve. I expect these units would have ported vacuum advance unless the air meter was modified from the '63/375 ported vacuum advance configuration.

I don't think any early 64 FI engines with a 375R FI unit used a 63 vacuum advance unit. The vacuum source was direct manifold vacuum, just like the 380 unit that replaced it.
The same small hex fitting that was used on the side of the 380 unit was also used on the 375R but it was located at the back of the plenum in the location normally used for power brake vacuum.

The parts book shows only the 1116236 for all 64's with FI. No mention of the 1116201 which was used for all 63 FI's.

(I don't know how this worked on 64's with the 375R unit AND power brakes)

[Duke W.]

Re: 1964 F.I. PCV location??

Corvette News Vol. 8 No. 2 has a 1965 tune-up specs chart. For 365 and 375 HP they give two sets of centrifugal specs, and a footnote for the second specs, which are identical to '63 says "Early 1963 production only". The vacuum advance specs are for the 236 VAC.

The above really doesn't make any sense, and it looks like I misconstrued this as early '64s using "left over" '63 distributors, but it does look like early '64 SHP/FI engines may have used the lazy '63 centrifugal curve.

It's quite possible they just changed the internal parts in the '64 distributors without changing the part numbers.

Geez, 30-30 cam, FI single plane manifold, and a lazy centrifugal curve....

Duke

[John D.]

Re: 1964 F.I. PCV location??

I don't think any early 64 FI engines with a 375R FI unit used a 63 vacuum advance unit. The vacuum source was direct manifold vacuum, just like the 380 unit that replaced it.
The same small hex fitting that was used on the side of the 380 unit was also used on the 375R but it was located at the back of the plenum in the location normally used for power brake vacuum.

The parts book shows only the 1116236 for all 64's with FI. No mention of the 1116201 which was used for all 63 FI's.

(I don't know how this worked on 64's with the 375R unit AND power brakes)

Michael, ARE you sure about this info??? This is the first time I have ever heard anyone say that a 375R does not have a PCV valve in the same configuration as a 63. I don't typically disagree with you (well maybe I do) but...... Do you have original pics of the 375R. I mean this is some really interesting info. I don't agree though but what do I know. I really haven't restored that many 375R's over the years. A dozen would be a lot. But I will tell you that every one of them had the same look as a typical 63 unit when they went out the door. What about the ones that had power brakes Michael. Doesn't make sense. Not to discredit your vast source of info and knowledge. You know I never do that. (fingers crossed) John D.
I will be seeing CC in person soon and will ask him this question. Hold the phone. A buddy of mine has an original 375 R that he has owned for 30 years. The car is not restored but is in the process. I will ask him also. Others please chirp in. John D

[Michael H.]

Re: 1964 F.I. PCV location??

Michael, ARE you sure about this info??? This is the first time I have ever heard anyone say that a 375R does not have a PCV valve in the same configuration as a 63. I don't typically disagree with you (well maybe I do) but...... Do you have original pics of the 375R. I mean this is some really interesting info. I don't agree though but what do I know. I really haven't restored that many 375R's over the years. A dozen would be a lot. But I will tell you that every one of them had the same look as a typical 63 unit when they went out the door. What about the ones that had power brakes Michael. Doesn't make sense. Not to discredit your vast source of info and knowledge. You know I never do that. (fingers crossed) John D.
I will be seeing CC in person soon and will ask him this question. Hold the phone. A buddy of mine has an original 375 R that he has owned for 30 years. The car is not restored but is in the process. I will ask him also. Others please chirp in. John D

That's not what I said. Read my post again.

[Dan H.]

Re: 1964 F.I. PCV location??

I'm still looking at Noland Adams book, page 229 in my copy, that has three 64 FI factory pictures in it. The top is a '375R' unit, it still has the air meter vacuum advance line as in 63 '375' units, PCV valve etc. Has power brakes using rear vacuum fitting. GM must have just 'recalibrated' 375 units as a fill-in for early 64. All else looks like 63.
Dan

[Michael H.]

Re: 1964 F.I. PCV location??

I'm still looking at Noland Adams book, page 229 in my copy, that has three 64 FI factory pictures in it. The top is a '375R' unit, it still has the air meter vacuum advance line as in 63 '375' units, PCV valve etc. Has power brakes using rear vacuum fitting. GM must have just 'recalibrated' 375 units as a fill-in for early 64. All else looks like 63.
Dan

Dan,

Is the pic of the 375R one from the assembly plant or is it possibly an early one from engineering?
Supposedly, the only difference between a 375 and a 375R is the location of the vacuum advance line and it's source. (the PCV valve and location is the same as a 63 375 unit)
The 375R gets vacuum from a small fitting in the rear of the plenum instead of from the top of the air meter.
I think Jerry Bramlett has a good pic of a 375R on his website. I'll see if i can find it.

Add on; Just found the pic of a 375R on Jerry's website. Hope the link works.

http://www.jerrybramlett.net/images/1964_E.jpg

[John D.]

Re: 1964 F.I. PCV location??

Corvette News Vol. 8 No. 2 has a 1965 tune-up specs chart. For 365 and 375 HP they give two sets of centrifugal specs, and a footnote for the second specs, which are identical to '63 says "Early 1963 production only". The vacuum advance specs are for the 236 VAC.

The above really doesn't make any sense, and it looks like I misconstrued this as early '64s using "left over" '63 distributors, but it does look like early '64 SHP/FI engines may have used the lazy '63 centrifugal curve.

It's quite possible they just changed the internal parts in the '64 distributors without changing the part numbers.

Geez, 30-30 cam, FI single plane manifold, and a lazy centrifugal curve....

Duke

Duke and others, The 375R and early 7380 units used a weird distributor setup. The points distributor is known as the 063. It's 100% identical to the '63 '022 distr with the exception of the 236 16 VA. You know of course that the 022 distr used the 201 VA for the -097 cam.
Problems arose with the 64 063 distr though. The engineer forgot that just changing the vacuum advance alone was a screw up. They forgot about changing the weights, springs, and the cam -and also the football on top of the main shaft. Thus the advance curve on a 063 leaves a lot to be desired. To recap: the 022 and 063 distrs are the same deal except for the vacuum advances and the tags.
The 375 R unit typically has Y nozzles where as the 63 unit typically has w or x nozzles. The 375 R uses a weaker spring behind the enrichment diaphragm cover for the 30-30 cam. Same spring as the 7380 units. Other than the nozzles and the spring I do believe it's the same identical unit. I can't think of a think else that is different.
I believe I have told everyone why the 375 R unit exists so i won't get in to that now. It was strictly business. Using up left over inventory while refining the new 7380 unit as requested by the St. Louis bosses because they had it with the cranking signal valve and the 63 Corvettes that wouldn't start up. That's the inside scoop that you won't read. Unless of course you have a copy of the memo St. Louis gave to RP via Frank Sciabica. John D.