Holley 4150/4160 Plastic Floats And Air Gap Manifolds

[toobroketoretire]

Several years ago on a HOT summer afternoon I began having trouble with my engine as it ran pretty rough when I was driving it and even worse when it was idling. I pulled it into my garage and noticed a STRONG smell of gasoline Uh oh. With it still running I opened my hood and a split second later KA-BOOM.............. it erupted in flames that went up to my garage rafters. I immediately shut it off and began spraying water onto the base of the flames and finally got the fire out. So what happened?

Holley has used three different kinds of floats; the common brass floats, plastic floats, and the "Nitrophyl" floats that are a solid black foam (like a QuadraJet float). My #3310 had the plastic floats and the front float got a split in it so it filled with gasoline; dropping the float and causing massive flooding from the front vent tube. As the gasoline shot out of the vent tube it saturated the front of my air filter and ran out; filling the large cavity under my intake runners with gasoline. Then a spark inside my HEI set it off. The Air Gap manifolds are great as long as there is no gasoline leak because gasoline will remain in the huge cavity..................a whole 1-1/2 QUARTS of gasoline.

I took my 4 spare #3310 Holleys apart and found one of them had the latest Nitrophyl floats so I put them into my Holley and threw the worthless plastic floats away. I was awfully lucky it happened in my garage and also lucky my garden hose just happened to be lying next to it. The fire melted the oil pressure line in two and melted both of the HEI connectors but that's all it did. Had I been driving it my '71 would have been destroyed because of that plastic float. If you are running a Holley I strongly recommend you update it to the latest Nitrophyl floats to prevent a float from filling with gasoline.

Oh yeah, and I now carry a fire extinguisher in my rear storage compartment just in case something like this ever happens again.

 

[Mac]

Closest I've come to something like that was with my father's 1971 GMC pickup. I'm not sure how or why but the top plate of the carb was loose. I smelled gasoline and was concerned. So I pulled to the side of the road, jumped out and left the motor running. I lifted the hood, spun the wingnut on the air cleaner then and saw raw gas dripping off the carb onto the hot exhaust manifold. Yikes!!

I backed away in shock, then, leaving the hood open, I walked around and shut off the ignition... and waited for a while to make sure nothing was going to go up in flames. After tightening the top of the carb back down, no further issues.

Mac

 

[toobroketoretire]

Closest I've come to something like that was with my father's 1971 GMC pickup. I'm not sure how or why but the top plate of the carb was loose. I smelled gasoline and was concerned. So I pulled to the side of the road, jumped out and left the motor running. I lifted the hood, spun the wingnut on the air cleaner then and saw raw gas dripping off the carb onto the hot exhaust manifold. Yikes!!

I backed away in shock, then, leaving the hood open, I walked around and shut off the ignition... and waited for a while to make sure nothing was going to go up in flames. After tightening the top of the carb back down, no further issues.

Mac

I was shocked to find fire extinguishers are so inexpensive..............less than $15 from Walmart. After that fire I'll be carrying a fire extinguisher all the time. It could save my C3 or someone's life.

 

[gmjunkie]

I was shocked to find fire extinguishers are so inexpensive..............less than $15 from Walmart. After that fire I'll be carrying a fire extinguisher all the time. It could save my C3 or someone's life.

Me personally,I'm not much of a Holley man!

"Holley" Trusted brand by Automotive Arsonists for over 100 years!