Flame arrestor at passenger side valve cover

[03BlkZ]

Ok gents please excuse my ignorance but I got a question. I am in the process of reassembling my 70 C10 from its restoration and I need to know if in need this guy or not. Looks like a flame arrestor that the hooks to the passenger side valve cover then to the hose and runs back to the carb/air cleaner. What is this actually for and could I just used a breather in that position? My engine is a 350 and will be using the Edelbrock performer rpm intake with the summit 650 CFM carb with electric choke and vacuum Secondaries. Again excuse my ignorance. I am still pretty new to working on older vehicles. Here is a pic.
Thanks!

[sick472]

The flame arrestor is usually abandoned when most redo the engine bay. The breather spacer, on the other hand, may come in handy to get the air cleaner to clear the carb workings (depending on your parts combo). I still use the spacer with a single snorkel air cleaner and an Edelbrock carb.

[03BlkZ]

Originally Posted by sick472

The flame arrestor is usually abandoned when most redo the engine bay. The breather spacer, on the other hand, may come in handy to get the air cleaner to clear the carb workings (depending on your parts combo). I still use the spacer with a single snorkel air cleaner and an Edelbrock carb.

I was planning to use the original factory air cleaner but I haven't checked the fit with the new carb. I wasn't sure if the carb needed that air for anything or if I could just put a breather there. Thanks

[Steeveedee]

That side is the gozinta for filtered air that the PCV system removes. I'd leave the arrestor inline, or optionally you could put a screen inside the air cleaner where that hose hooks up. Older vehicles used a simple screen. Check around in the '60-'66 forum, you should be able to find a pic. Just having a breather will potentially allow dust into that valve cover, depending on how dusty the conditions are. The spacer will ensure that the air cleaner housing clears the carburetor air horn. The air cleaner housing may clear anyway, you'll just have to check.

[chevy71super]

What ever you do just be conscious of your ventilation system. I fought oil leaks for years. Recently I went back to the original PVC design with a “vent” on the right side up to the air cleaner using early 70’s Camaro parts and a PVC on the left. Solved most of my oil my leak problems. Engine is now properly “ventilated” and with good gaskets oil leaks are a thing of the past!

PS. I didn’t understand how important a proper engine ventilation system was until I read through the posts on this board on the subject. Great group of knowledgeable people on this board!

[dmjlambert]

I was looking for the post and thought I had it bookmarked but I guess I can't find it now. Somebody here made an explanation that: normally the vent side with the flame arrestor is where fresh air goes into the engine, and the PCV valve side is where the blow by and other unburned fuel/oil saturated dirty air comes out of the engine. That dirty air is then sucked into the intake and burned as fuel. There are conditions of load especially as the engine gets more wear, there is more blow by and air will actually come out of both the fresh air inlet and the PCV valve. That is when it is useful to have the flame arrester and hose to the air cleaner, so that dirty air is also sucked into the carburetor and burned. If you use a breather, which is a minimal filter, that dirty air will come out and dirty the valve cover and engine compartment and stink up the cab.

[03BlkZ]

Ok so I did a test fit on my engine and to use the original air cleaner I will need to retain these parts. Does anyone know where I can find the rubber hose or what it's even called so I can research buying parts. I think the flame arrestor is good to reuse I will just clean it up ad well as the metal riser but the hose is severely dry rotted. I guess I could always just go to a parts store and buy some hose but this one looks pretty bent. Thoughts? Here is a pic of my engine just for the hell of it.

[dmjlambert]

I think your best bet on the hose is to post a want to buy ad in the part section. They come up for sale on eBay sometimes. eBay is where I got mine. The hose will often come with a flame arrester and perhaps also the air cleaner spacer.

[03BlkZ]

Originally Posted by dmjlambert

I think your best bet on the hose is to post a want to buy ad in the part section. They come up for sale on eBay sometimes. eBay is where I got mine. The hose will often come with a flame arrester and perhaps also the air cleaner spacer.

Thanks

[Grumpy old man]

When looking for spark arrestor or hose don't forget that marine engines use a similar system and aren't priced too bad . Double check size before ordering . cut to fit .

https://marineenginedepot.com/hose-c...flame-arrestor

[71CHEVYSHORTBED402]

Originally Posted by Grumpy old man

When looking for spark arrestor or hose don't forget that marine engines use a similar system and aren't priced too bad . Double check size before ordering . cut to fit .

https://marineenginedepot.com/hose-c...flame-arrestor

Great information Grumps, I need one myself.

[Rich72C10]

Interesting thing talking about marine engines... My intake ended up having a nice crack in it. I was able to find a NOS Marine Intake that was not only manufactured much later than '72 but was the exact match for my 72 engine!

[LockDoc]

-
Try your local parts store for the hose. I got one at NAPA a few years ago. They had to order it and it came in the next day. Take the old one with you.

LockDoc

[Ol Blue K20]

I got the hose from Napa too. I just bought a 3/4" heater hose with a 90* at the end and trimmed it to fit.

[rechinca]

If you’re considering or wanting an aftermarket air cleaner instead of the original style, you just need to get a flat base and not a drop base. I had to do that to fit the HEI / Edelbrock Performer and 1406 carb combo. JUST fits.

[pjmoreland]

Gates part # 28475 fits well in place of the original spark arrestor hose. I bought it at O'Reilly. It doesn't have the hard plastic inner liner like the original though. I had to route mine to the driver side valve cover since I have Vortec heads. I cut the Gates hose a little longer than the original to account for the added height of my aftermarket intake manifold. I had to cut a new notch on the top of the air cleaner spacer to accommodate the alignment boss on the air cleaner since the spacer is on backwards.

[randy.powell]

Classic Industries has this hose also...
RP

[Rich72C10]

Originally Posted by Grumpy old man

When looking for spark arrestor or hose don't forget that marine engines use a similar system and aren't priced too bad . Double check size before ordering . cut to fit .

https://marineenginedepot.com/hose-c...flame-arrestor

Thank's Grumpy, assuming the diameter is okay, then just cut to fit past the 90 degree?

Boo, out of stock

Edit: Wonder about this Dorman 46061 Crankcase Ventilation Hose

• Helps ensure proper engine performance and engine longevity
• Made from oil-resistant materials

The Dorman 46061 has an inside diameter of .441 In. (app 7/16") and an outside diameter of .732 In. (app 3/4")
It is a very sturdy molded rubber PCV hose.

Just need to pull off the hose again (I wrapped in tape for now) and measure it.

[dmjlambert]

There's other marine engine stores to consider as well. Just poking around on the Internet I see this https://www.myinboardmarine.com/prod...e-pcm-r045008c

[Rich72C10]

thanks!

[DocZz]

Originally Posted by pjmoreland

Gates part # 28475 fits well in place of the original spark arrestor hose. I bought it at O'Reilly. It doesn't have the hard plastic inner liner like the original though. I had to route mine to the driver side valve cover since I have Vortec heads. I cut the Gates hose a little longer than the original to account for the added height of my aftermarket intake manifold. I had to cut a new notch on the top of the air cleaner spacer to accommodate the alignment boss on the air cleaner since the spacer is on backwards.

Looks awesome!

[71CHEVYSHORTBED402]

Originally Posted by dmjlambert

I was looking for the post and thought I had it bookmarked but I guess I can't find it now. Somebody here made an explanation that: normally the vent side with the flame arrestor is where fresh air goes into the engine, and the PCV valve side is where the blow by and other unburned fuel/oil saturated dirty air comes out of the engine. That dirty air is then sucked into the intake and burned as fuel. There are conditions of load especially as the engine gets more wear, there is more blow by and air will actually come out of both the fresh air inlet and the PCV valve. That is when it is useful to have the flame arrester and hose to the air cleaner, so that dirty air is also sucked into the carburetor and burned. If you use a breather, which is a minimal filter, that dirty air will come out and dirty the valve cover and engine compartment and stink up the cab.

Interesting. Helps explain why my C20 leaks so much oil. "Chrome don't get you home".

[Rich72C10]

Well, after cleaning out my Flame arrestor and ~50 miles later not a single drop of oil.

I would have little streams of oil on the pan and on the cover before I cleaned the Flame arrestor. I can't believe it was so easy to fix after all this time trying to figure out my oil leak.

[Grumpy old man]

If your looking for a new one don't forget the vette suppliers .

https://www.corvettecentral.com/1521...iABEgKSgvD_BwE

[Rich72C10]

Thanks grumpy for that too, I think mine cleaned up okay but I might just get one for the hell of it!