66 327/350 carb question

[Rich G.]

[Peter M.]

Re: 66 327/350 carb question

Rich,
I don't have a 66, but I think that was the first year for the divorced style choke thermostat (sits in a well on the intake manifold).
The 66 exhaust manifold didn't have a choke stove. The flooding could be caused by many things, but this will give you a bump to the top.
Kind regards

[Leif A.]

Re: 66 327/350 carb question

Rich,
Peter is correct. If your '66 327 has the original (style) intake manifold and the original (style) Holley 4160 List 3367 carburetor, then you should have a divorced choke setup as shown in the picture below of my '67 L79. Your '66 should be the same type setup...if stock configuration.

[Gary B.]

IMG_0528.jpg

Gary

[Rich G.]

Re: 66 327/350 carb question

Thanks for that info. Looks like I am missing that set up but it could be added as opposed to having the “wrong” exhaust manifold . I do have the stock manifold. I will double check. The previous owner (22 years ago) put the carb with the electric choke on. I guess I’ll find out why when I look tomorrow.

Regarding the carb issue, I’m leaning toward a sticking float as it has not done the dripping in the last two days but we are going back at it tomorrow.

Rich

[Mark E.]

Re: 66 327/350 carb question

Nozzle drip is often caused by inadequate idle air bypass. Insufficient idle air bypass requires a higher throttle position (idle speed screw adjustment) to achieve idle speed. This engages the primary venturi at idle causing it/them to drip.

So two possibilities if this is the cause of the dripping-
- This carburetor is not calibrated for this engine, meaning your engine wants more idle air bypass than this carb delivers.
- At least one side of the idle air bypass is obstructed.

Does your other carb have this issue? If not, it could be because it's calibrated for this application.

[Rich G.]

[Mark E.]

Re: 66 327/350 carb question

Yes, it could be dirt or built up fuel residue. Also, sometimes they are resized or modified.

[Leif A.]

Re: 66 327/350 carb question

Leif,

This is the PVC hose I removed from my ‘66. I was under the impression that ‘66 and ‘67 L79s used the same hose. My hose has a formed-in, almost 90 degree bend just before it connects to the carb. I see that the hose on your ‘67 L79 does not have that formed-in bend. The ‘66 JG shows a photo of that hose, but it’s not possible to definitively tell from that photo if there is a formed-in 90 degree bend or not. The photo perspective in the JG is not ideal for making that assessment. Do you have any further insight into this issue?

Gary

[ATTACH=CONFIG]119584[/ATTACH]

Gary

Gary,
Do you know if the hose you're showing is factory original? Everything I've ever read (A.I.M., TIM&JG, P&A catalog) show just a length of hose as I pictured. The 427/390 and the later 350 cu in engines used the PCV hose with the 90* bend as the PCV was installed on the driver's side valve cover...although the good Doctor does show #3831055 as pre-formed. Dunno.

[Rich G.]

Re: 66 327/350 carb question

Thanks Mark. I watched a YouTube video on idle circuits so I know a little more now. Your suggestion gives us something to look at.

[Gary B.]

Re: 66 327/350 carb question

Leif,

I cannot attest to its originality. I found another posting by Scott Smith that shows a similar hose, with his supposition of originality.

https://www.forums.ncrs.org/showthre...664#post578664

[Gary B.]

IMG_0538.jpg

[Leif A.]

Re: 66 327/350 carb question

Leif,

I cannot attest to its originality. I found another posting by Scott Smith that shows a similar hose, with his supposition of originality.

https://www.forums.ncrs.org/showthre...664#post578664

The old LIC catalog suggests the hose with the 90 degree bend is specific to 427/4-barrel cars. The ‘66 JG has no mention of any PCV hoses having 90 degree bend, regardless of engine option. I think more research is needed for the JG if in fact some engines had the 90 deg bend hose, but the JG makes no such mention. Does the ‘67 JG talk about any PCV hose with a 90 deg bend?

Gary

Gary,
It does not.

[Leif A.]

Re: 66 327/350 carb question

Leif,

I think the reproduction hose I bought some years ago that I was planning on using was purchased from Doc Rebuild. In thinking about it, I think it’s fair to be suspicious of the claim of an “accurate … reproduction” when the same reproduction hose is meant to be used a replacement for three different GM part numbers. Three GM parts numbers implies three different hose designs.

[ATTACH=CONFIG]119593[/ATTACH]

I believe the GM part number for the PCV hose for ‘66/‘67 300 HP and 350 HP engines was 3831055. Which is one of the three numbers in the Doctors “accurate” claim.

Gary

Gary,
That is correct...but nowhere, as I stated earlier, does it show that hose to have a vulcanized/pre-formed bend.

[Rich G.]

Re: 66 327/350 carb question

Just to close things out, moving the metering block from the good carb (the one with the divorced choke which couldn’t be used with my aftermarket intake manifold) to the rebuilt carb with the electric choke that WAS still leaking internally, fixed that carb.