MTFCA Forum

I have done all the regular things over the years, put cardboard behind, yard stick pieces, tightened and so on. The tank baffles are still soldered in and were pinned years ago with the solder. What have you all done to stop the drumming?

Remove the baffles from the muffler.

Has nothing to do with the muffler! Are you sure the noise is coming from inside the tank? There should be two strips of webbing material at the top and a fiber panel behind it. The straps which hold it in place hook in the area above the tank below the windshield with threaded end through the firewall with nut on the engine side. They should hold the tank tight. I am presuming the tank is in the cowl. Some models have it under the back seat.
Norm

Hows your over flow pipe? Could it be hitting a baffle

Original gas caps were pot metal with a steel base washer.
Very common to find that washer in the bottom of a tank.

Norman, just because John didn't add a smiling emoji to his muffler post does not mean he was not joking. A loud muffler will certainly drown out a drumming fuel tank noise.

Thank you John. I had a chuckle over your comment.

Allan from down under.

Tighten all 8 frame to firewall bracket bolts and the body bolts. It’s likely the dash / body not the fuel tank. Also do you have the proper gasket / weatherstrip on the fuel door / cowl vent?

It is the tank for sure. Stops when passenger pushes up on the bottom. (coupe) Tank is tight with straps and has insulation on the straps and cardboard behind. Nothing loose inside.

Allan wrote: ↑

Mon Nov 04, 2024 8:01 pm

Norman, just because John didn't add a smiling emoji to his muffler post does not mean he was not joking. A loud muffler will certainly drown out a drumming fuel tank noise.

Thank you John. I had a chuckle over your comment.

Allan from down under.

You got it. T's make a lot of noises. I find it best to ignore the normal rattles until they change into knocks & bangs.
Just enjoy the ride.

How about some of that insulating/sound deadening stick on floor stuff?

The cars tend to take a resonating sound at certain speeds. My wife says she hears bagpipes when I am driving along. She has some hearing loss so she hears some frequencies more than others. I don't hear the bagpipes. I have rocky mountain brakes from Temecula on mine and I hear the rods rattling when on bumpy roads.
Norm

Did I miss it? But I did not hear anything about the top straps.

When I hand built the cowl tank for my speedster I use only one baffle. It used to drum appreciably as the fuel level dropped< so i kept the tank topped up. When I had it out later to fix a miniscule weep on a welded seam, I added two rods between flat sections of the tank, welding them at each end to seal them. No more drumming then.

Allan from down under.