carburetor neck

[geezer#99]

Originally Posted by S_Gibson

Not to bring an ancient thread back from the grave, but I've been pondering what to do with this hose that is sticking up connected to nothing. I just found this thread while browsing another another.

I have a hose that just sticks up from my passenger side valve cover that looks like it has one of these flame arresters. Reading this post is it safe to say it is not needed with the air cleaner I have? If not should I just leave it sticking up as is, put a breather over the passenger side cover or just remove it and plug the hole? I'm guessing plugging the hole is unwise. There also appears to be a place on the bottom of my air cleaner the I could attach run this hose to, but I would need to find a molded hose to make the 2 bends.

Suggestions?

You need to filter the air that is drawn into your motor with that hose. It likely originally hooked to the riser barb.
You can hook it to your present air cleaner. You don’tneed A molded hose. Use a short length of hose with a plastic 90 degree elbow. You can buy barbed elbows in the plumbing section of the hardware store.
You can’t plug the hose or plug the valve cover. You need an air supply into your motor to make the pcv work right.

[Steeveedee]

Originally Posted by S_Gibson

Not to bring an ancient thread back from the grave, but I've been pondering what to do with this hose that is sticking up connected to nothing. I just found this thread while browsing another another.

I have a hose that just sticks up from my passenger side valve cover that looks like it has one of these flame arresters. Reading this post is it safe to say it is not needed with the air cleaner I have? If not should I just leave it sticking up as is, put a breather over the passenger side cover or just remove it and plug the hole? I'm guessing plugging the hole is unwise. There also appears to be a place on the bottom of my air cleaner the I could attach run this hose to, but I would need to find a molded hose to make the 2 bends.

Suggestions?

That would be the hose that has filtered air to replace what blow-by the PCV valve pulls out. As it is, you are allowing dust and moisture to enter your engine's guts.

[dmjlambert]

Originally Posted by S_Gibson

...
Suggestions?

Yes, what geezer#99 and ncpetersc said. What I would add is:
If the place on the air cleaner housing that would accept the hose is open and just sucking in unfiltered air, you should probably correct that anyway, so you might as well hook up the hose leading from your flame arrester on the valve cover.
If you are interested in the most "stock" setup, you would get one of those spacers with the hose connector on it as shown in the very first post with the arrow pointing to it, and get an original style air cleaner, and you would be complete. I have seen the stock air cleaner assembly usually is listed for about $60-$90 used here on the board and on eBay, and the spacer goes for about $15-$35.

[S_Gibson]

Thanks a ton for the input. I was about to pull it out of the valve cover hole and put a breather aver it. I shall connect this to the inlet hole on the bottom of the air cleaner. I took this picture when I got the truck weeks ago, but just noticed both these items last weekend when I started cleaning up the nasty looking engine compartment.

I also noticed I need spark plug wire looms. Someone put an HEI distributor on the truck, but the wires are zip tied together laying against the exhaust manifolds.

Another item under the hood that looks (non) stock it the Edelbrock carburetor. I know the previous owner traded 2 miniature pony for this engine about 5 years ago. That may have been when the air cleaner was replaced.

[Steeveedee]

Two ponies for a bunch of horses? Good trade!

[S_Gibson]

Originally Posted by Steeveedee

Two ponies for a bunch of horses? Good trade!

Lol, heck yeah. They were two cute miniature ponies. One a blonde the other black. He is a neighbor and my daughter used to go over every day and play with those ponies. His wife always joked they were just lawn ornaments so when the engine in the truck went out he traded the two ponies for this new engine.

He wasn't a mechanic and was the 3rd owner of this truck. The second owner of this truck lives about a half mile away from us and is his mechanic. He also mentioned the original owner is a local as well. This truck has lived it's entire life within the same 5 miles since it was purchased nearly 49 years ago.

I was just stoked when he decided to finally sell it. Then he offered me a heck of a deal on it. Imagine I paid him about what those 2 miniature ponies went for

[GerhardH]

Originally Posted by dmjlambert

Ok folks this is what I ended up doing. I searched high and low and made several trips to parts stores, speed shop, and to the Chevrolet dealer. I went to AutoZone, O'Reilly, Advance, and nobody could help me with grommets for the valve covers. A guy at the speed shop said to go to O'Reilly and buy a couple of breather covers, open the packages and chuck the new breathers in the trash and get the grommet out of the package, and that was the only way I was getting a grommet. I thought that sounded like something I didn't want to do. I became acquainted with a guy in the parts department at the Chevy dealer that had been around since the days of 67-72. He ordered me some that did not turn out to be the right size, but he researched further and ordered some that fit. 3 trips to the Chevy dealer and now I have some that fit. Perfectly.

I carefully clipped and removed the old grommets a piece at a time and made sure nothing fell down inside. Inserted the grommets and the PCV valve and flame arrester.

With the new grommet, inserting the flame arrester was extremely difficult. I used a little white grease and pushed and twisted, crawled up on top of the engine and put all my weight on it and pushed and twisted some more. Halfway through the process I removed the grommet and put it on the flame arrester and tried to work the grommet into the hole on the valve cover. That didn't work. I decided since this was going to be hard as hell, I would stop, take a break and do some good cleanup on the flame arrester and give it a shot of gloss black paint and work more to insert it after a couple of days. I put the grommet back on the valve cover and was eventually able to insert the flame arrester into it. It was not easy at all, it was hard as hell. But it did eventually pop in. Looks great now, and I won't be re-visiting that job for years (I hope).

I measured the valve cover holes at 15/16 inch.
Breather/flame arrester grommet part number 14091870
PCV valve grommet part number 3989350
PCV valve part number 6487779 (right angle elbow)

The PCV valve is the one with right angle elbow, I know that is not stock for 1969, but I like it. The one from Chevy is more solid built than the one I got at O'Reilly and I decided since I would just get the right part right there right now. The PCV valve grommet with the slant is probably also not stock for 1969 according to the parts guy, and the breather/flame arrester grommet would also work for the PCV valve just fine. But I like the slanted one.

Hello my friend do you have the number of the flame arrester too please?

[dmjlambert]

Hi Gerhard,
I don't know the number of the flame arrester and I believe that is a part that is no longer available new. I cleaned mine and painted it black. Is yours missing or old/dirty/rusty?

[GerhardH]

Originally Posted by dmjlambert

Hi Gerhard,
I don't know the number of the flame arrester and I believe that is a part that is no longer available new. I cleaned mine and painted it black. Is yours missing or old/dirty/rusty?

Thanks!
At the moment I like to build an exact blueprint of my engine:-)

[dmjlambert]

Are you partially done with the blueprint? I would like to see that. It sounds very interesting.

[Astro-Balls]

This is what the flame arrestor looks like on my '67. on the bottom of the air cleaner.

[GerhardH]

Originally Posted by dmjlambert

Are you partially done with the blueprint? I would like to see that. It sounds very interesting.

.

Servus David, here you can see everything done until now:

http://67-72chevytrucks.com/vboard/s...d.php?t=760400

[GerhardH]

Today during waiting for drying fresh paint, I have picked up some pictures:

[GerhardH]

#2

[GerhardH]

The arrestor is probably 3857476, but in the catalog is not mentioned for 1968 327?

[FirstOwner69]

The original from my early 1969 with a 350 is #3287094.

[GerhardH]

Yes I have the same.
See is the patent number, not the GM part number.

[GerhardH]

Found out that the NOS flame arrestor #3857476 is wrong- too big, see picture. Fortunatly I have a complete set from our fellow ROOGER KOOP here in the forum.

See: http://67-72chevytrucks.com/vboard/s...51#post8823851

Hose measurement:
ID : approx 10 mm = approx. 0.39" = probably 3/8"
OD: approx 30 mm = approx 1.18"

[GerhardH]

The set from ROOGER

[Swedchevy67]

Originally Posted by dmjlambert

Ok, folks, it arrived and fits well. Here is a related problem. After doing some research I figured out that the part that fits on the rocker arm cover is called a flame arrester. Then there is a hose that goes to the air cleaner spacer. It all fits together fine, except the guy who rebuilt my engine took the flame arrester and hose off of the rocker arm cover. There is nothing I can do to get the flame arrester back on. It is a simple round peg trying to fit in a round hole, and it just won't go. I even tried removing the flame arrester from the hose, cleaning up the flame arrester, greasing the end and putting a large socket over it and hitting it with a mallet. I do not see any obstruction. The rubber grommet is not soft like the one on the PCV valve side of the engine. Do I need to remove the rocker arm cover and replace the grommet? This one thing is turning out to be a pain in the rear.

I believe I got the same problem.
Don’t know the fitting order.

[dmjlambert]

I don't know what any of those items in your picture are.

Most of this thread is about the small block 350 engine spacer between the carburetor and air cleaner, and the hose that leads to a flame arrester that plugs into the passenger side valve cover. This makes up the breather part of the positive crankcase ventilation (PCV) system. The post that you quoted from me is when I described the great difficulty I had plugging the flame arrester into the passenger side valve cover. I ended up getting a new grommet, but it was still very difficult to insert.

The other half of the PCV system is a one way valve called a PCV valve on the driver side valve cover with a vacuum hose that goes to the base of the carburetor.