66 L72 L36 PCV carb clip orientation

[Ronald L.]

On UPC L72 Sheet C3 they show a clip that does under the pass front carb nut to hold the pcv hose in place. On TF cars I have pics of this clip open face up. The asy manual illustration shows id open face down.

Which is correct?

Second - is it L36 only that gets the second clip inserted under the left side manifold bolt? That part does not seem to show in the 66 AIM...

[Michael H.]

Re: 66 L72 L36 PCV carb clip orientation

On UPC L72 Sheet C3 they show a clip that does under the pass front carb nut to hold the pcv hose in place. On TF cars I have pics of this clip open face up. The asy manual illustration shows id open face down.

Which is correct?

Second - is it L36 only that gets the second clip inserted under the left side manifold bolt? That part does not seem to show in the 66 AIM...

Here's a pic of a brand new 66 425 HP. The open end of the carb stud mounted clip appears to be facing up.

I think only the L36/390 HP had the clip attached to an intake manifold bolt.

[Jack H.]

Re: 66 L72 L36 PCV carb clip orientation

"The asy manual illustration shows id open face down."

Remember, the AIM was intended for GM internal communication (design engineering to production). They did NOT take great pains getting the drawings 100% accurate if the PN's called out were self-explanatory to those who assembled the vehicle.

So, things like the exact placement of tie wraps, the exact qty/vehicle, their specific orientation often varied widely from what's depicted in AIM drawings. Between the obvious nature of the parts involved and the quantity per vehicle called out by the bill of materials, it just wasn't worth the drafting expense to make the AIM be a Mona Lisa...

[Ronald L.]

Re: 66 L72 L36 PCV carb clip orientation

Thanks guys, that is why I asked for the clarification.

Michael, two things, L68...did you mean L36/390HP?

And second, pictures is so small can't see anything after it has been db-ized, would it be possible to send me via email a larger picture?

[Michael H.]

Re: 66 L72 L36 PCV carb clip orientation

Thanks guys, that is why I asked for the clarification.

Michael, two things, L68...did you mean L36/390HP?

And second, pictures is so small can't see anything after it has been db-ized, would it be possible to send me via email a larger picture?

Yup, sorry. Should be L36, not L68. I'll correct my post.

I'll try to get/post a better picture.

[Rich P.]

Re: 66 L72 L36 PCV carb clip orientation

Interesting picture. Looks pre production not sure but looks liks a painted black A/C lid and the lable on the fan shroud. And no HP rating.

Rich

[Michael H.]

Re: 66 L72 L36 PCV carb clip orientation

Interesting picture. Looks pre production not sure but looks liks a painted black A/C lid and the lable on the fan shroud. And no HP rating.

Rich

Rich,

It's not pre production, but it is an early car. Yes, the air cleaner is black, just like a 396 engine in 65. That would be correct for early 66 L72.

There's at least one more item (well, items actually. there are two symetrically opposite items) in the pic that are "borrowed" from a 65 396. See if you can spot it.

[Rich P.]

Re: 66 L72 L36 PCV carb clip orientation

Looks like acorn fuel line nuts.

It's been 10 years since I did my last 66 L-72 did all fuel lines run like this or did later ones run up inside the water pump?

I love quiz time

Rich

[Michael H.]

Re: 66 L72 L36 PCV carb clip orientation

Looks like acorn fuel line nuts.

It's been 10 years since I did my last 66 L-72 did all fuel lines run like this or did later ones run up inside the water pump?

I love quiz time

Rich

Yup, you got it. The carburetor bowls are carry over from 65 with the small acorn nuts.

The fuel line is correct as is.

How about the clamp on the radiator over flow hose? I've seen several original 66 big block cars with this same clamp.

Warning sticker or coolant instructions label on the fan shroud.

[Rich P.]

Re: 66 L72 L36 PCV carb clip orientation

Yes I have seen the Whittek #2 clamp on overflow hoses on 66 and 67 BB's.

Rich

[Ronald L.]

Re: 66 L72 L36 PCV carb clip orientation

My Dec 65 BB from a long time ago had that clamp on the over flow.

Back to the topic...

Michael - there is no way on earth or any other planet that this clip goes face up on a 66 BB 390 HP with original intake and carb.

If you locate it face up you cannot install the air cleaner base. Well you'd have to bend the clip down 1/4 to 1/2 inch so the base fits down on the carb. That is of course if the repro part is of the correct configuration.


It makes a lot of sense its attached as shown in the AIM too, in that it keeps the hose low to go into the cross manifold clip just before going into that super rare original PCV valve...which valve should it be for a 390 HP anyway???



Now I have two other questions now that we are staring at the top of this intake:

1. The small clip that holds the vac advance tube - was that on the engine intake bolt prior to engine paint?

2. The throttle return spring bracket - was this on there & painted orange too?

[Joseph T.]

Re: 66 L72 L36 PCV carb clip orientation

1. yes
2. yes

[Michael H.]

Re: 66 L72 L36 PCV carb clip orientation

My Dec 65 BB from a long time ago had that clamp on the over flow.

Back to the topic...

Michael - there is no way on earth or any other planet that this clip goes face up on a 66 BB 390 HP with original intake and carb.

If you locate it face up you cannot install the air cleaner base. Well you'd have to bend the clip down 1/4 to 1/2 inch so the base fits down on the carb. That is of course if the repro part is of the correct configuration.


It makes a lot of sense its attached as shown in the AIM too, in that it keeps the hose low to go into the cross manifold clip just before going into that super rare original PCV valve...which valve should it be for a 390 HP anyway???



Now I have two other questions now that we are staring at the top of this intake:

1. The small clip that holds the vac advance tube - was that on the engine intake bolt prior to engine paint?

2. The throttle return spring bracket - was this on there & painted orange too?

Ron,

I don't think the carburetor stud mounted PCV hose bracket was used on a 390 HP.

I think the 390 HP used only the intake manifold bolt location bracket on the left side.

By the way, the actual bracket used in production for the 425 HP looks nothing like one pictured in the AIM. The "real thing" is flat, not bent down as pictured.

[Ronald L.]

Re: 66 L72 L36 PCV carb clip orientation

I know the carb clip has two simple bends, 390 and 425 are different parts as per LIC or any of the other big box parts stores. The 425 clip would work fine with the open face down.

Any one have other original cars 390 for comment?

In all the pictures I have of 390 or 425 66 cars, there is not a one that is correct in the usage of these clips, and other areas as well... bolts and brackets so the lack of this clip or the one under #2 bolt can't be judged by studying these cars too much, some were even routed to the rear.

Nor do any of these pictures with the carb clip face up show the air cleaner which means they were probably file pictures taken prior to addition of the air cleaner - you'll know its wrong then unless the AC asy was installed with the brutus method.

[Michael H.]

Re: 66 L72 L36 PCV carb clip orientation

I know the carb clip has two simple bends, 390 and 425 are different parts as per LIC or any of the other big box parts stores. The 425 clip would work fine with the open face down.

Any one have other original cars 390 for comment?

In all the pictures I have of 390 or 425 66 cars, there is not a one that is correct in the usage of these clips, and other areas as well... bolts and brackets so the lack of this clip or the one under #2 bolt can't be judged by studying these cars too much, some were even routed to the rear.

Nor do any of these pictures with the carb clip face up show the air cleaner which means they were probably file pictures taken prior to addition of the air cleaner - you'll know its wrong then unless the AC asy was installed with the brutus method.

There is only one clip/support shown for 425 HP in the AIM. It's flat with a loop for the hose at the end. It looks nothing like the drawing in the AIM for 425 HP. I have an original.

There is NO carburetor stud mounted clip/support shown in the AIM for a 390 HP engine. The only clip/support for 390 HP is the one mounted to a LH intake manifold bolt. It's not shown in the AIM because the clip/support was installed at Tonawanda. Not St Louis.

I've had the carburetor stud mounted flat clip with the open end up on my 66 for decades and the air cleaner definitely fits just fine.

Look at the pic of a new 425 HP on page 355 of the Noland Adams book. There is only one support, it's mounted to the RF carburetor stud and the open end is definitely up.
There is no left side support, at all.