The Stovebolt Site Forums The Shop Area Engine Shop Getting ready for KC. Screw fell into the intake.

I decided to do some cleaning to get the truck ready for the trip to KC. While cleaning under the hood I knocked one of the rear air cleaners off. I have had difficulty keeping it on, it uses set screws that don't hold very well so I tightened one side and went to the other and it did not seem to what to hold. I took the cleaner off and no set screw. Question is where did it go, down in the carb or on the floor and how long has it been gone. The carbs were taken off a couple weeks ago and clean and adjusted. ?????????? Something to fuss about on a 1300 mile trip.

Ron
If it happened a couple weeks ago and you have been driving it, well, it's too late now.
Just a thought, how about replacing the set screws with wing bolts?
https://www.amazon.com/Thumb-Screws-1-4-20/s?ie=UTF8&page=1&rh=n%3A16410621%2Cp_11%3A1%2F4%22-20

See ya Friday and you have my number if you have any issues.

Don

It happened last night.

Got a magnet? Pass it around the general area and see what sticks. I would think the chances of it falling down the throat of the carburetor would be pretty slim. Have a safe trip and say howdy to the gang for Ms Kathy and I.

I had a 1963 Falcon in my college days and something fell through the carb and chipped a piston. The repair bill was to be $75 but when they got done they had added $50 more, 1964, so I called my father and he came down and disputed the charge so they went back to the original charge.

Try the magnet like the guy from Central Oklahoma advises... A friend of mine bought a car real cheap for a simular thing when he found the wing nut from the air breather in the carb and it choked the motor out ,,the owner sold it for way less.. of course my friend didnt know this til after her bought it.. so the magnet is good advice Ron. just in case.. have a good trip and most likely you do not have this problem

WELL, I decided to start it and I have a clattering sound so I shut it off immediately. I can not see how such a small set screw could get to the piston from the carb, it has 2 carbs and the manifold is setting at down angle from the intake. Would there be enough vacuum to suck it into the cylinder?

If it did drop into the carburetor throat and you started the engine the screw is now either rattling around in the intake valve train or bouncing on top of a piston. I’m really surprised it went that way but stranger things have happened. Now it’s time to move this discussion up to the Engine Bay for help.

Magnet on a cable (don't want to loose the magnet too!)
or
Shop vac (nylon stocking in the hose line to see what you catch)
or
Bore Scope (don't lose that little camera in the passages)

About 45 years ago, before I was bitten by the "buy American" bug, I bought a 1970 Toyota Corona, with about 150k miles. It was ready for a major tune-up, and I noticed there was only 1 screw (and 1 empty) hole holding the choke plate in place. Didn't hear any strange racket, so drove about another 50k miles, and then rebuilt the engine. Number 3 piston top had a perfect indentation of a choke plate screw. Evidently, the screw made it through both intake and exhaust valves; at any rate, it was no longer in the engine.

If it were mine, I would TRY:

(1) Installing a new bag in the shop vacuum
(2) Gently rotating the engine by hand until a piston was at top dead center
(3) Remove the spark plug from that cylinder
(4) Put the adapter on the vacuum that allows it into tight places, and go through the spark plug hole.
(5) Replace the spark plug
(6) Repeat 2 through 5 five more times
(7) Check the vacuum bag.

No guarantee, but what I would try.

Jon.

1963 GMC Carryall V6, doing a carb O/H in a rest area along side I-40 back in 1973. After everything was back together I noticed one mounting nut missing. Found another in my toolbox and we were on the road again, I thought. As soon as I fired up the engine it sounded like a rod was trying to beat its way out the side of the block. 90 miles away from home and dirt poor we had no choice but to move on. Drove the final 20 miles to our destination (big dune buggy meet) with the hard clacking driving me nuts. After the meet was over we headed the 110 miles back home pulling the buggy on the trailer. About 40 miles from home the noise went away. No noticeable difference in how the truck ran. It bugged me so much that I pulled both heads finding the missing nut melted into the top of #4 piston. Put it all back together (left the nut where it was) and put another 20000 miles on without any troubles.🛠

WOW! Takes a lickin' and keeps on tickin'!

Thanks for sharing, Dean

Pull the spark plugs. Use a borescope through the plug holes to inspect the combustion chambers. The one I use has a probe 5MM in diameter, and fits through a .22 caliber rifle barrel. It's even got a 45 degree mirror attachment for looking sideways. I think I gave less than $50.00 on Ebay for it, and it paid for itself the first time I used it on a mechanical inspection because I didn't have to waste half a day sitting around while someone pulled a cylinder head to confirm a damaged piston.
Jerry

This NOT an engine story but a story about my upcoming trip to KC.

So..... you don’t want any help with the engine noise? You’re the one that brought up the engine noise. Let me know and I’ll have the thread deleted.