aav-26 stromberg carb

[mr41cadillac]

anyone have a  picture of the needle and parts on a  stromberg  aav-26 carbureator ? thanks john

[Steve Passmore]

To what needle are you referring?

[mr41cadillac]

I need the float hanger for aav-26 carb. I'm told without it gas could flood in the engine. anyone know where I can get this part, it goes thru the hole in the needle. I don't see it in the rebuild kits.  john

[Steve Passmore]

So your looking at the part defined as 'AR' named as 'Clip'  which is the part I have already shown you a picture of yes?   There is no way gas can flood the engine without this part as I have already said it does the opposite, it prevents the needle from sticking shut and starving the float bowl. I have just dismantled a carb looking for the clip but it has a replacement needle kit which has no clip hole in the needle anyway and was running for years like that.

[mr41cadillac]

ok that's what I thought. I took the top off the carb and I don't see anyway the needle can come out. I think my adviser is wrong in what he told me.  my rebuild kit does however have a hole thru  the needle. so it must though what you said. another thing, th e part that the needle goes in, the part that  screws  in , was finger tight, it has a gasket, so could this have caused the carb to leak ? john

[Steve Passmore]

another thing, th e part that the needle goes in, the part that  screws  in , was finger tight, it has a gasket, so could this have caused the carb to leak ? john

It sure would. The fuel would be able to by-pass the needle.

[mr41cadillac]

steve we put carb. back on with the part you sent picture of , runs great. my friend says you need this part since it prevents needle from falling out or also getting cocked. it would then cause hydro lock and could bend a rod. while rare in his 50 year careen he says he saw hydro lock occur 2 times and it was caused by the needle falling out. in fact he says carter did away with this part and came back with it after a lawsuit. thanks john

[Steve Passmore]

I have no idea what carbs your friend has worked on but I have lost count of the dozens of these aero type I have rebuilt and currently have two on the bench right now and if all the parts are correct and not damaged I can tell you its a physical impossibility for the needle to drop out or get 'cocked'   They are deigned that way.
Look at the two pictures, one with a clip and one without, and you will see that when the float is at its maximum bottom travel the needle is barely 1/3 of the way out of its housing. The float actually bottoms in the chamber before it even gets this far.    It can't happen.

Hydro-lock, seen it a few times. The very word hydro means water. A massive sudden ingestion of water into the cylinder when the engine is turning fast will indeed lock and cause bent rods. Usually happens when the car is driven into floods.  I can't in my wildest imagination visualize a situation where fuel could do this unless you drive through a flood of gasoline or scream the engine to top revs and pour a can of fuel into the carburettor.   
Even if the needle could drop out the car would start to flood and stall long before there was enough to fill all the cylinder to lock it up. It would take mass's of fuel and without the engine running where would this come from?  Electric pump? maybe, then the owner would have to be negligent to leave it switched on for long enough. After which the engine just would not start and most of this fuel would go to the sump, still not causing damage.

[mr41cadillac]

hes saying hydro lock can be water or gas. hes seen where the flat tab actually broke off.

[Steve Passmore]

Well if the flat tab broke off even having the clip there is not going to save needle dropping out. You must believe whatever you want to.

[mr41cadillac]

by all means your right steve

[pauldridge]

I have personally experienced recently, a "hydro" lock (a quick Google confirms this is correct terminology).

Surprising in my 1998 GMC truck.  It seems I've had an injector valve issues for quite some time.  While at the shop for diagnosis, a technician got in and attempted to start the truck.. it went about 1/2 revolution, then locked up.  We had to remove the head and pan to discover that a rod had literally snapped in two during the starting attempt.  We all surmise that the offending injector cylinder (yes, it was the same one) allowed fuel to flow into the cylinder, creating a lock.

pretty amazing that the starter would have enough torque to snap that rod, but we can't come up with any other explanation.

A new rod and new fuel rail, and the truck has now been back on the road for some 1,000 miles or so without further incident.